Ontogeny of the cortisol stress response and glucocorticoid receptor expression during early development in channel catfish, Ictalurus punctatus.
The objective of this study was to investigate the ontogeny of the cortisol and GR stress response in channel catfish (Ictalurus punctatus) at several early life stages. To accomplish this, resting and stress-induced levels of tissue cortisol and the two catfish GRs (GR-1 and GR-2) expression were measured. Resting cortisol levels in newly fertilized eggs averaged 2.4 ± 0.2 ng/egg and decreased to 0.4 ± 0.01 ng/egg by day 5. Cortisol levels in newly fertilized eggs subjected to an acute stress (lowered dissolved oxygen from 6.5 mg/L to 1.8 mg/L) averaged 2.3 ± 0.1 ng/egg and decre...
Source: Comparative Biochemistry and Physiology. Part A, Molecular and integrative physiology. - February 8, 2019 Category: Physiology Authors: Peterson BC, Chatakondi NG, Small BC Tags: Comp Biochem Physiol A Mol Integr Physiol Source Type: research

The Environmental Tolerances and Metabolic Physiology of Sablefish (Anoplopoma fimbria).
This study focuses on the sablefish (Anoplopoma fimbria), an emerging aquaculture species that has a unique ecology in the wild. For instance, adults inhabit oxygen minimum zones and cool waters at depths up to 1500 m. Using Atlantic salmon (Salmo salar) (~1132 g adults) as a comparative species, we used intermittent-flow respirometry to characterize the tolerance and metabolic response of sablefish (~10 g juveniles and ~675 g adults) to acute increases in temperature (2 °C h-1) and decreases in oxygen level (~10% air saturation h-1). Adult sablefish were much more hypoxia tolerant than adult salmon [O2 lev...
Source: Comparative Biochemistry and Physiology. Part A, Molecular and integrative physiology. - February 8, 2019 Category: Physiology Authors: Leeuwis RHJ, Nash GW, Sandrelli RM, Zanuzzo FS, Gamperl AK Tags: Comp Biochem Physiol A Mol Integr Physiol Source Type: research

Is the teleost heart oxygen limited? - Insights using "hyperoxic" incubations of contracting cardiac tissue from rainbow trout.
In conclusion, the heart of female rainbow trout may be oxygen-limited in vitro and this study raises new questions about the choice of appropriate PO2 for experimentation, the relevance of elevated and varying PO2 to measurements of cardiac performance, and the possible existence of an oxygen sensor within rainbow trout cardiomyocytes. PMID: 30738911 [PubMed - as supplied by publisher] (Source: Comparative Biochemistry and Physiology. Part A, Molecular and integrative physiology.)
Source: Comparative Biochemistry and Physiology. Part A, Molecular and integrative physiology. - February 7, 2019 Category: Physiology Authors: Gesser H, Rodnick KJ Tags: Comp Biochem Physiol A Mol Integr Physiol Source Type: research

Temperature dependent pre- and postprandial activity in Pacific bluefin tuna (Thunnus orientalis).
In this study, we present results in a captive population that demonstrate strong effects of ambient temperature on the tail beat frequency and swimming speed of a pelagic fish in both pre- and post-prandial states. We measured the responses of a ram ventilator, the Pacific bluefin tuna (Thunnus orientalis), after digestion of a meal to explore the impacts of the metabolic costs of digestion on behavior and respiration. A combination of respirometry, physiological biologging of visceral temperatures, and activity monitoring with accelerometry were used to explore the metabolic costs of digestion and the impacts on ventilat...
Source: Comparative Biochemistry and Physiology. Part A, Molecular and integrative physiology. - February 5, 2019 Category: Physiology Authors: Gleiss AC, Dale JJ, Klinger DH, Estess EE, Gardner LD, Machado B, Norton AG, Farwell C, Block BA Tags: Comp Biochem Physiol A Mol Integr Physiol Source Type: research

Metabolic Effects of Epinephrine on the Crab Neohelice granulata.
This study was designed to identify the physiological role of Epinephrine (E) in the intermediary metabolism of the burrowing crab Neohelice granulata and how E regulates the metabolism in crabs fed with a high-carbohydrate (HC) or a high-protein (HP) diet. To answer these questions, we evaluated in vivo the effects of E injections on glucose and triglycerides in the hemolymph and tissue glycogen levels of crabs fed with HC or HP diet. An in vitro investigation was carried out to assess the direct effects of E on glycogenolysis, lipolysis and glycolysis pathways in the hepatopancreas, mandibular muscle and anterior and pos...
Source: Comparative Biochemistry and Physiology. Part A, Molecular and integrative physiology. - February 5, 2019 Category: Physiology Authors: Model JFA, Dos Santos JT, Da Silva RSM, Vinagre AS Tags: Comp Biochem Physiol A Mol Integr Physiol Source Type: research

The effects of salinity and photoperiod on aerobic scope, hypoxia tolerance and swimming performance of coho salmon (Oncorhynchus kisutch) reared in recirculating aquaculture systems.
Abstract Land-based recirculating aquaculture systems (RAS) have been used to rear salmon from smolt to market-sized adults, but high operating costs have limited their wide spread adoption. One clear advantage of using RAS for salmon aquaculture over open net pens is that fish can be reared under optimal conditions in an attempt to maximize growth and physiological performance and reduce overall production costs. However, few studies have attempted to define the optimal conditions for the long-term rearing of salmon. Thus, the goal of this study is to determine the effects of salinity and photoperiod, two factors...
Source: Comparative Biochemistry and Physiology. Part A, Molecular and integrative physiology. - February 4, 2019 Category: Physiology Authors: Fang Y, Chan VKS, Hines CW, Stiller KT, Richards JG, Brauner CJ Tags: Comp Biochem Physiol A Mol Integr Physiol Source Type: research

Effect of ration level on growth performance, body composition, intermediary metabolism and serum parameters in juvenile Patagonian blennie Eleginops maclovinus.
This study aimed to determine the optimum feed ration during 90 days based on growth performance, body composition, intermediary metabolism, and serum parameters. For this, fish were randomly assigned to rations of 0.5, 1, 2 and 4% of body weight. No fish mortality was registered, but all fish, developed fatty liver. The results of weight, length, growth performance (WGR, SGR), and body parameters (HSI, VSI and K) followed a similar pattern, with the lowest values observed in the 0.5% and no significant differences between rations of 1, 2 and 4%. The feed intake and feces increased with the feed ration. However, the perc...
Source: Comparative Biochemistry and Physiology. Part A, Molecular and integrative physiology. - January 28, 2019 Category: Physiology Authors: Oyarzún R, Martínez D, Soto-Dávila M, Muñoz JLP, Dantagnan P, Vargas-Chacoff L Tags: Comp Biochem Physiol A Mol Integr Physiol Source Type: research

Modulation of stress and innate immune response by corticosteroids in pacu (Piaractus mesopotamicus).
Abstract Understanding how stress and corticosteroid modulates the innate immune response is one of the keys to improving productivity and reducing losses in intensive aquaculture. Thus, we investigated the effects of dietary corticosteroids (7 days; long-term exposure) and transport (4 h; short-term stress) on stress and innate immune response in pacu. For this end, fish were fed with diets containing dexamethasone (100 mg kg-1) or hydrocortisone (200 mg kg-1), followed by transport, and then were intraperitoneally inoculated with heat-killed Aeromonas hydrophila or PBS (sham-inoculation). Fish were s...
Source: Comparative Biochemistry and Physiology. Part A, Molecular and integrative physiology. - January 28, 2019 Category: Physiology Authors: Zanuzzo FS, Sabioni RE, Marzocchi-Machado CM, Urbinati EC Tags: Comp Biochem Physiol A Mol Integr Physiol Source Type: research

A study on the physiological and behavioral mechanisms underlying the differences in survival capacity between two cyprinid fish species.
Abstract The crucian carp (Carassius auratus) and common carp (Cyprinus carpio) are close relatives and coexist in most of their natural habitats but with different levels of abundance. The crucian carp is usually more abundant than the common carp in high predation-pressure habitats. To verify whether the crucian carp exhibits a significantly higher survival capacity combined with additional antipredator strategies than the common carp, we measured the morphology, behavioral traits, fast-start escape swimming performance and survival time under predation in both fish species. Additionally, the relationships betwe...
Source: Comparative Biochemistry and Physiology. Part A, Molecular and integrative physiology. - January 28, 2019 Category: Physiology Authors: Fu C, Cui YL, Xu JJ, Wang Y, Fu SJ Tags: Comp Biochem Physiol A Mol Integr Physiol Source Type: research

Dietary inclusion effect of feed ingredients showing high feeding attractiveness to rockfish (Sebastes schlegeli Hilgendorf 1880) on the growth performance, feed utilization, condition factor and whole body composition of fish (II).
In conclusion, the greatest weight gain, amount of feed supply and CF of rockfish were obtained in the JM diet, followed by the SM, PM, SQM, SHM and Con diets, in order. PMID: 30695736 [PubMed - as supplied by publisher] (Source: Comparative Biochemistry and Physiology. Part A, Molecular and integrative physiology.)
Source: Comparative Biochemistry and Physiology. Part A, Molecular and integrative physiology. - January 26, 2019 Category: Physiology Authors: Kim HS, Cho SH Tags: Comp Biochem Physiol A Mol Integr Physiol Source Type: research

Effects of biodensity on the growth, stress physiology, and welfare of Arctic charr (Salvelinus alpinus) in freshwater.
Abstract Biodensity is a major factor affecting the production and welfare of farmed fishes. Arctic charr (Salvelinus alpinus) (average mass 176.9 ± 3.9 g) were held at biodensities of 30, 60, 90, 120, and 150 kg/m3 (4 replicates per treatment) during a 91 day study which examined key growth, stress physiology, and welfare parameters. During experimentation fish were fed to near satiety, and a random subsample of 20 fish (5 per replicate tank) were collected from each treatment every 21 days. Biodensity was found to have no significant effect on mortality rates or physical fin damage. Growth rat...
Source: Comparative Biochemistry and Physiology. Part A, Molecular and integrative physiology. - January 25, 2019 Category: Physiology Authors: Sevier A, Smith R, Benfey T, Danzmann R, Bernier N, Moccia R Tags: Comp Biochem Physiol A Mol Integr Physiol Source Type: research

What can we learn from glucocorticoid administration in fish? Effects of cortisol and dexamethasone on intermediary metabolism of gilthead seabream (Sparus aurata L.).
We described a higher energy expenditure associated to both corticosteroids resulting in lower growth rates of fish. Moreover, the effects of these compounds were tissue-dependant, with differences between both hormones. Thus, cortisol-fed animals accumulated triglycerides in the liver, while DXM treatment led to glycogen storage. Cortisol and DXM stimulated amino acids catabolism and gluconeogenic pathways in muscle and gills, but the effects were significantly enhanced in DXM-fed fish. The described effects highlighted differentiated mechanisms of action associated to both corticosteroids under chronic stress conditions....
Source: Comparative Biochemistry and Physiology. Part A, Molecular and integrative physiology. - January 25, 2019 Category: Physiology Authors: Jerez-Cepa I, Gorissen M, Mancera JM, Ruiz-Jarabo I Tags: Comp Biochem Physiol A Mol Integr Physiol Source Type: research

A novel crustacean hyperglycemic hormone (CHH) from the mud crab Scylla paramamosain regulating carbohydrate metabolism.
In this study, a new cDNA encoding type I CHH peptide, termed Sp-CHH3, was isolated from the mud crab Scylla paramamosain and its potential functions were investigated. The full length cDNA of Sp-CHH3 was identified as encoding a 127-aa precursor composed of a 27-aa signal peptide, a 23-aa CHH precursor-related peptide and a 75-aa mature peptide with a typical motif of CHH. Phylogenic analysis suggested that, Sp-CHH3 is a previously unreported CHH from S. paramamosain. Tissue distribution analysis showed that Sp-CHH3 was mainly expressed in the eyestalk ganglia, thoracic ganglia, stomach and the ovary. A RNA interference e...
Source: Comparative Biochemistry and Physiology. Part A, Molecular and integrative physiology. - January 25, 2019 Category: Physiology Authors: Liu A, Liu J, Chen X, Lu B, Zeng C, Ye H Tags: Comp Biochem Physiol A Mol Integr Physiol Source Type: research

Short- and long-term low-salinity acclimation effects on the branchial and intestinal gene expression in the European seabass (Dicentrarchus labrax).
Abstract The European seabass (Dicentrarchus labrax) is a teleost remarkably adapted to a wide range of water salinity, through osmoregulatory mechanisms, mainly operating in the gills and the intestine. As an important aquaculture species, its rearing in low-salinity conditions offers benefits for its inland culture. However, this demands a full comprehension of the European seabass osmoregulatory mechanisms and its response to acclimation protocols. The purpose of this study was to evaluate different acclimation protocols in terms of osmoregularity and stress response, following transferring of European seabass ...
Source: Comparative Biochemistry and Physiology. Part A, Molecular and integrative physiology. - January 25, 2019 Category: Physiology Authors: Kokou F, Con P, Barki A, Nitzan T, Slosman T, Mizrahi I, Cnaani A Tags: Comp Biochem Physiol A Mol Integr Physiol Source Type: research

Rapid metabolic compensation in response to temperature change in the intertidal copepod, Tigriopus californicus.
This study demonstrates a time course of rapid metabolic compensation in response to temperature that occurs in a small intertidal animal, and suggests intertidal invertebrates can thermally acclimate within a few hours of a significant temperature change. PMID: 30690151 [PubMed - as supplied by publisher] (Source: Comparative Biochemistry and Physiology. Part A, Molecular and integrative physiology.)
Source: Comparative Biochemistry and Physiology. Part A, Molecular and integrative physiology. - January 25, 2019 Category: Physiology Authors: Scheffler ML, Barreto FS, Mueller CA Tags: Comp Biochem Physiol A Mol Integr Physiol Source Type: research

Metabolic and functional impacts of hypoxia vary with size in Atlantic salmon.
Abstract The most capricious environmental variable in aquatic habitats, dissolved O2, is fundamental to the fitness and survival of fish. Using swim tunnel respirometry we test how acute exposure to reduced O2 levels, similar to those commonly encountered by fish in crowded streams and on commercial aquaculture farms, affect metabolic rate and swimming performance in Atlantic salmon of three size classes: 0.2, 1.0 and 3.5 kg. Exposure to 45-55% dissolved O2 saturation substantially reduced the aerobic capacity and swimming performance of salmon of all sizes. While hypoxia did not affect standard metabolic rate,...
Source: Comparative Biochemistry and Physiology. Part A, Molecular and integrative physiology. - January 25, 2019 Category: Physiology Authors: Oldham T, Nowak B, Hvas M, Oppedal F Tags: Comp Biochem Physiol A Mol Integr Physiol Source Type: research

Pharmacological characterization of the 5-HT1A receptor of Bombyx mori and its role in locomotion.
This study provides the first information of serotonin receptor on pharmacological in silkworm and on individual functions in arthropods. PMID: 30690153 [PubMed - as supplied by publisher] (Source: Comparative Biochemistry and Physiology. Part A, Molecular and integrative physiology.)
Source: Comparative Biochemistry and Physiology. Part A, Molecular and integrative physiology. - January 25, 2019 Category: Physiology Authors: Chen P, Xiong R, Zhao W, Chen X, Li T, Li H, Li Y, Shen W Tags: Comp Biochem Physiol A Mol Integr Physiol Source Type: research

Boldness in early emerging rainbow trout: A metabolic cost with no return?
Abstract The timing with which salmonid larvae emerge from their gravel nests is thought to be correlated with a particular suite of behavioural and physiological traits that correspond to the position of the individual on the bold-shy continuum. Aggressiveness, dominance and resilience to stress characterise bold individuals and are potentially interesting traits to exploit in aquaculture production. In the present study a series of experiments were performed, with the purpose of characterising behavioural, metabolic and production related traits in rainbow trout juveniles from different emergence fractions. Newl...
Source: Comparative Biochemistry and Physiology. Part A, Molecular and integrative physiology. - January 25, 2019 Category: Physiology Authors: Skov PV, de Jesus Gregersen J, Gesto M, Jokumsen A Tags: Comp Biochem Physiol A Mol Integr Physiol Source Type: research

Hymenoptera flight muscle mitochondrial function: Increasing metabolic power increases oxidative stress.
Abstract Insect flight is a high intensity activity, but biomechanical and metabolic requirements may vary depending on life style and feeding mode. For example, bees generally feed on pollen and nectar, whereas wasps also actively hunt and scavenge heavy prey. These variations in metabolic demands may result in different capacities of metabolic pathways in flight muscle, and utilisation some of these pathways may come at a cost of increased free radical production. To examine how metabolic requirements and oxidative stress vary between species, we explored the variation in flight mechanics and metabolism of the h...
Source: Comparative Biochemistry and Physiology. Part A, Molecular and integrative physiology. - January 21, 2019 Category: Physiology Authors: Hedges CP, Wilkinson RT, Devaux JBL, Hickey AJR Tags: Comp Biochem Physiol A Mol Integr Physiol Source Type: research

Gonadal steroids and energy availability during ovarian maturation stages of the Amazonian pirarucu Arapaima gigas (Teleostei: Osteoglossidae) in the wild.
Abstract The Amazonian pirarucu, Arapaima gigas, belongs to a phylogenetically basal group of teleosts (family Osteoglossidae). The commercial importance and the overexploited status of natural stocks of A. gigas brought the interest to rear it in the Amazon region, but rearing techniques are not fully understood to obtain reproduction success. Gonadal steroids (plasma and cephalic liquid), lipids and proteins (muscles, liver and ovary) of wild A. gigas females were analyzed during one year on Mexiana Island (Amazon Basin, Brazil) and ovarian maturation stages were described. The sexual gender determination method...
Source: Comparative Biochemistry and Physiology. Part A, Molecular and integrative physiology. - January 17, 2019 Category: Physiology Authors: Amaral JS, Venturieri RL, Moreira RG Tags: Comp Biochem Physiol A Mol Integr Physiol Source Type: research

Muscle growth mechanisms in response to isoenergetic changes in dietary non-protein energy source at low and high protein levels in juvenile rainbow trout.
This study investigates muscle growth mechanisms in juvenile rainbow trout in response to isoenergetic changes in dietary non-protein energy (NPE) source (F, fat vs. C, carbohydrates) at two levels of digestible protein to digestible energy (DP/DE) ratio. Fish (initial weight 32.4 g) were fed four diets having similar DE levels (~18 kJ g-1) with a high (HP/E~26 mg kJ-1) vs. low (LP/E~14 mg kJ-1) DP/DE ratio using F or C as major NPE source (7 week-experiment). The lowering of dietary DP/DE ratio increased myoblast determination protein 1a (myod1a) and decreased myostatin 1b (mstn1b) and cathepsin D (ctsd) muscl...
Source: Comparative Biochemistry and Physiology. Part A, Molecular and integrative physiology. - January 17, 2019 Category: Physiology Authors: Alami-Durante H, Cluzeaud M, Bazin D, Schrama JW, Saravanan S, Geurden I Tags: Comp Biochem Physiol A Mol Integr Physiol Source Type: research

Hypoxia alters the expression of hif-1a mRNA and downstream HIF-1 response genes in embryonic and larval lake whitefish (Coregonus clupeaformis).
Abstract Lake whitefish (Coregonus clupeaformis) embryos and larvae were exposed to hypoxia at different developmental ages to determine when the cellular response to hypoxia could be initiated. mRNA levels of hypoxia-inducible factor 1α (hif-1α), hsp70, and several HIF-1 target genes were quantified in embryos at 21, 38, 63, 83- and 103-days post fertilisation (dpf) and in larvae at 1, 2, 3- and 4-weeks post hatch (wph) following a 6-h hypoxia exposure. hsp70 mRNA levels were increased in response to hypoxia at all embryonic ages. By comparison, the first observed change in hif-1α mRNA in respon...
Source: Comparative Biochemistry and Physiology. Part A, Molecular and integrative physiology. - January 16, 2019 Category: Physiology Authors: Whitehouse LM, Manzon RG Tags: Comp Biochem Physiol A Mol Integr Physiol Source Type: research

Molecular characterization of ecdysis triggering hormone and its receptor in citrus red mite (Panonychus citri).
In this study, we identified and characterized the full-length cDNA of ETH and ETHR in citrus red mite Panonychus citri (McGregor). Phylogenetic analysis indicated that PcETHR was closely related to the insect ETHR subtype B. A calcium mobilization-based functional assay showed that PcETH activated the PcETHR in a dose-dependent manner. Furthermore, a sharp upregulation of PcETH before ecdysis was observed by quantitative real-time PCR (qRT-PCR), and it revealed a tight correlation of ETH signaling and the molting process. These are the first insights into the molecular characterization of ETH and its receptor in mites as ...
Source: Comparative Biochemistry and Physiology. Part A, Molecular and integrative physiology. - January 16, 2019 Category: Physiology Authors: Zhu L, Zhang W, Li G, Sun QZ, Wang JJ, Smagghe G, Jiang HB Tags: Comp Biochem Physiol A Mol Integr Physiol Source Type: research

Coping with climatic extremes: Dietary fat content decreased the thermal resilience of barramundi (Lates calcarifer).
Abstract Aquatic organisms, including important cultured species, are forced to contend with acute changes in water temperature as the frequency and intensity of extreme weather events worsen. Acute temperature spikes are likely to threaten aquaculture species, but dietary intervention may play an important protective role. Increasing the concentration of macronutrients, for example dietary fat content, may improve the thermal resilience of aquaculture species, however, this remains unexplored. To evaluate this hypothesis, we used two commercially available diets (20% versus 10% crude fat) to examine if dietary fa...
Source: Comparative Biochemistry and Physiology. Part A, Molecular and integrative physiology. - January 16, 2019 Category: Physiology Authors: Gomez Isaza DF, Cramp RL, Smullen R, Glencross BD, Franklin CE Tags: Comp Biochem Physiol A Mol Integr Physiol Source Type: research

Effect of increased rearing temperature on digestive function in cobia early juvenile.
S, Le MH, Rønnestad I Abstract The present study is focused to elucidate the main characteristics of the digestive function of this carnivorous fast-growing fish living at high temperatures. With this aim, we have examined the effects of an increased temperature from 30 to 34 °C on the daily pattern of gastrointestinal pH, enzymatic proteolytic digestive activity and the feed transit time in early juveniles of cobia (Rachycentron canadum), a species living in tropical and subtropical waters with an increasing aquaculture production. Fish were fed two meals a day. Gastric luminal pH was permanently ac...
Source: Comparative Biochemistry and Physiology. Part A, Molecular and integrative physiology. - January 11, 2019 Category: Physiology Authors: Yúfera M, Nguyen MV, Navarro-Guillén C, Moyano FJ, Jordal AO, Espe M, Conceição LEC, Engrola S, Le MH, Rønnestad I Tags: Comp Biochem Physiol A Mol Integr Physiol Source Type: research

The effects of crowding stress on the growth, physiological response, and gene expression of the Nrf2-Keap1 signaling pathway in blunt snout bream (Megalobrama amblycephala) reared under in-pond raceway conditions.
This study demonstrates that high density-induced antioxidant defenses were involved in modifications to the enzymatic and transcriptional regulation of Nrf2-Keap1 signaling molecules and that M. amblycephala growth was reduced in a crowded IPRS. PMID: 30641189 [PubMed - as supplied by publisher] (Source: Comparative Biochemistry and Physiology. Part A, Molecular and integrative physiology.)
Source: Comparative Biochemistry and Physiology. Part A, Molecular and integrative physiology. - January 11, 2019 Category: Physiology Authors: Yang Z, Xu G, Ge X, Liu B, Xu P, Song C, Zhou Q, Zhang H, Zhang W, Shan F, Sun C Tags: Comp Biochem Physiol A Mol Integr Physiol Source Type: research

Comparative analysis of vertebral transcriptome in Japanese seabass (Lateolabrax japonicus) fed diets with varying phosphorus/calcium levels.
Abstract Aquaculture jeopardizes the aquatic environment by discharge of the most dietary phosphorus (P) into the water. Reducing the dietary P level is a common approach for decreasing the P discharge but it may result in increased risk of P deficiency leading to vertebral deformities. However, the molecular mechanism of vertebral deformities is poorly understood. We assessed vertebral transcriptome and compared the genes associated with bone metabolism in Japanese seabass (Lateolabrax japonicus) fed three diets containing different P and Ca levels including: diet I (0.4% P, 0.3% Ca), diet II (0.8% P, 0.3% Ca) an...
Source: Comparative Biochemistry and Physiology. Part A, Molecular and integrative physiology. - January 3, 2019 Category: Physiology Authors: Lu KL, Rahimnejad S, Ji ZL, Zhang CX, Wang L, Song K Tags: Comp Biochem Physiol A Mol Integr Physiol Source Type: research

Cyclin-dependent kinase 2 (Cdk-2) from the White shrimp Litopenaeus vannamei: Molecular characterization and tissue-specific expression during hypoxia and reoxygenation.
epiz-Plascencia G Abstract The cell cycle comprises a series of steps necessary for cell growth until cell division. The participation of proteins responsible for cell cycle regulation, known as cyclin dependent kinases or Cdks, is necessary for cycle progression. Cyclin dependent kinase 2 (Cdk-2) is one of the most studied Cdks. This kinase regulates the passage through the G1/S phase and is involved in DNA replication in the S phase. Cdks have been extensively studied in mammals, but there is little information about these proteins in crustaceans. In the present work, the nucleotide and amino acid sequence of Cd...
Source: Comparative Biochemistry and Physiology. Part A, Molecular and integrative physiology. - December 27, 2018 Category: Physiology Authors: Nuñez-Hernandez DM, Camacho-Jiménez L, González-Ruiz R, Mata-Haro V, Ezquerra-Brauer JM, Yepiz-Plascencia G Tags: Comp Biochem Physiol A Mol Integr Physiol Source Type: research

Adrenergic and adenosinergic regulation of the cardiovascular system in an Antarctic icefish: Insight into central and peripheral determinants of cardiac output.
Abstract Icefishes characteristically lack the oxygen-binding protein haemoglobin and therefore are especially reliant on cardiovascular regulation to augment oxygen transport when oxygen demand increases, such as during activity and warming. Using both in vivo and in vitro experiments, we evaluated the roles for adrenaline and adenosine, two well-established cardio- and vasoactive molecules, in regulating the cardiovascular system of the blackfin icefish, Chaenocephalus aceratus. Despite increasing cardiac contractility (increasing twitch force and contraction kinetics in isometric myocardial strip preparations) ...
Source: Comparative Biochemistry and Physiology. Part A, Molecular and integrative physiology. - December 27, 2018 Category: Physiology Authors: Joyce W, Egginton S, Farrell AP, Axelsson M Tags: Comp Biochem Physiol A Mol Integr Physiol Source Type: research

Forskolin reduces fat accumulation in Nile tilapia (Oreochromis niloticus) through stimulating lipolysis and beta-oxidation.
This study evaluated the role of forskolin on reducing fat accumulation in Nile tilapia (Oreochromis niloticus) by using in vitro and in vivo experiments. The use of 50 μM forskolin in vitro increased free fatty acid and glycerol release, but decreased triglyceride in adipocytes and hepatocytes. The adipose triglyceride lipase (ATGL), protein kinase cAMP-dependent type I regulatory subunit alpha (PKAR I) and other genes related to β-oxidation (peroxisome proliferator activated receptor alpha, PPARα and carnitine O-palmitoyltransferase 1, CPT1) were significantly up-regulated. After feeding a high-fat diet f...
Source: Comparative Biochemistry and Physiology. Part A, Molecular and integrative physiology. - December 26, 2018 Category: Physiology Authors: Zhang H, Wen JJ, Zhang YN, Limbu SM, Du ZY, Qin JG, Chen LQ Tags: Comp Biochem Physiol A Mol Integr Physiol Source Type: research

Molecular characterization and tissue distribution of SREBP-1 and PPAR α in Onychostoma macrolepis and their mRNA expressions in response to thermal exposure.
In this study, the coding sequences (CDS) of SREBP-1 and PPARα were firstly identified and characterized from Onychostoma macrolepis, encoding peptides of 1136 and 470 amino acids, respectively. The functional domains in O. macrolepis SREBP-1 and PPARα proteins retained the high similarity with those of other animals, at 74.69% and 77.29%, respectively. The mRNA encoding SREBP-1 was primarily expressed in the muscle and PPARα was highly expressed in the liver and intestine. Under thermal exposure, the content of non-esterified fatty acid (NEFA) decreased gradually after 1 h in the liver and muscle of O....
Source: Comparative Biochemistry and Physiology. Part A, Molecular and integrative physiology. - December 26, 2018 Category: Physiology Authors: Deng W, Yu HB, Sun J, Chang ZG, Gou NN, Huang CC, Zhao JL, Zhou JS, Ji H Tags: Comp Biochem Physiol A Mol Integr Physiol Source Type: research

The effect of salinity and photoperiod on thermal tolerance of Atlantic and coho salmon reared from smolt to adult in recirculating aquaculture systems.
Abstract Land-based, closed containment salmon aquaculture involves rearing salmon from smolt to adult in recirculating aquaculture systems (RAS). Unlike in open-net pen aquaculture, rearing conditions can be specified in RAS in order to optimize growth and physiological stress tolerance. The environmental conditions that yield optimal stress tolerance in salmon are, however, unknown. To address this knowledge gap, we reared Atlantic (Salmo salar) and coho (Oncorhynchus kisutch) salmon in 7 separate RASs for 400 days post-smoltification under 2 photoperiods (24:0 or 12:12, light:dark) and 4 salinities (2.5, 5, 1...
Source: Comparative Biochemistry and Physiology. Part A, Molecular and integrative physiology. - December 24, 2018 Category: Physiology Authors: Hines CW, Fang Y, Chan VKS, Stiller KT, Brauner CJ, Richards JG Tags: Comp Biochem Physiol A Mol Integr Physiol Source Type: research

Seasonal acclimatization and thermal acclimation induce global histone epigenetic changes in liver of bullfrog (Lithobates catesbeianus) tadpole.
Abstract The American bullfrog (Lithobates catesbeianus) is a eurythermal amphibian that is naturally distributed from subarctic to subtropical areas. The tadpoles of this species overwinter, in water, in cold environments. Therefore, they may have adapted to a wide range of temperatures in an active state. To understand the adaptation mechanisms to cope with low or high temperatures, we investigated global epigenetic modifications, histone variants, transcript levels of related genes, and the cellular acetyl coenzyme A (acetyl-CoA) and free CoA (CoA-SH) levels, in the livers of tadpoles collected in summer and wi...
Source: Comparative Biochemistry and Physiology. Part A, Molecular and integrative physiology. - December 24, 2018 Category: Physiology Authors: Ishihara A, Sapon MA, Yamauchi K Tags: Comp Biochem Physiol A Mol Integr Physiol Source Type: research

Sarco/endoplasmic reticulum Ca2+ ATPase (SERCA) transcript abundance in Y-organs and ecdysteroid titer in hemolymph during a molting cycle of the Blue Crab, Callinectes sapidus.
Abstract Crustacean growth is characterized by molting, whereby the old exoskeleton is shed and replaced by a new and larger version. The cellular events that lead to molting are driven by steroid hormones (ecdysteroids) secreted by paired endocrine glands (Y-organs). Between molts, ecdysteroid production is suppressed by a polypeptide molt-inhibiting hormone (MIH) released from neurosecretory cells in the eyestalks. Although a decrease in the MIH titer precedes the upsurge in ecdysteroidogenesis, it is hypothesized that a positive regulatory signal is also required for full activation of Y-organs. Existing data p...
Source: Comparative Biochemistry and Physiology. Part A, Molecular and integrative physiology. - December 18, 2018 Category: Physiology Authors: Roegner ME, Roer RD, Watson RD Tags: Comp Biochem Physiol A Mol Integr Physiol Source Type: research

Anoxia tolerance of the adult Australian Plague Locust (Chortoicetes terminifera).
Abstract Optimal breeding conditions for locust swarms often include heavy rainfall and flooding, exposing individuals to the risk of immersion and anoxia. We investigated anoxia tolerance in solitarious and gregarious adults of the Australian Plague Locust, Chortoicetes terminifera, by measuring the time to enter an anoxic coma after submersion in water, the time for recovery of ventilation and the ability to stand on return to air. We found a longer time to succumb in immature adults that we attribute to a larger tracheal volume. Time to succumb was also longer after autotomizing the hindlegs to reduce the energ...
Source: Comparative Biochemistry and Physiology. Part A, Molecular and integrative physiology. - December 18, 2018 Category: Physiology Authors: Robertson RM, Cease AJ, Simpson SJ Tags: Comp Biochem Physiol A Mol Integr Physiol Source Type: research

Molecular characterization and juvenile hormone-regulated transcription of the vitellogenin receptor in the cabbage beetle Colaphellus bowringi.
Abstract The vitellogenin receptor (VgR) is highly expressed in the ovaries where it is responsible for vitellogenin (Vg) deposition during oogenesis in insects. Therefore, identifying the VgR of insect pests, and understanding the mechanism regulating its expression, could lead to the development of pest management strategies based on disrupting reproduction. We cloned and identified VgR in the cabbage beetle, Colaphellus bowringi, which is a serious pest of cruciferous vegetables in Asia. The regulation of VgR transcription by juvenile hormone (JH) was also investigated. The results show that C. bowringi VgR cDN...
Source: Comparative Biochemistry and Physiology. Part A, Molecular and integrative physiology. - December 13, 2018 Category: Physiology Authors: Liu W, Guo S, Sun D, Zhu L, Zhu F, Lei CL, Sheng L, Phelps B, Wang XP Tags: Comp Biochem Physiol A Mol Integr Physiol Source Type: research

Food restriction, but not seasonality, modulates the acute phase response of a neotropical bat.
Abstract Season and food intake are known to affect immune response of vertebrates yet their effects on metabolic rate have been rarely explored. We tested the effect of season and acute food restriction and their interaction on the energetic cost of immune response activation of a tropical vertebrate, the Seba's short-tailed fruit bat (Carollia perspicillata). We specifically stimulated the acute phase response (APR) with bacterial lipopolysaccharide (LPS) to measure metabolic changes along with changes in body temperature (Tb), body mass (Mb), white blood cell counts and the Neutrophil/Lymphocyte ratio (N/L). We...
Source: Comparative Biochemistry and Physiology. Part A, Molecular and integrative physiology. - December 13, 2018 Category: Physiology Authors: Cabrera-Martinez LV, L Gerardo Herrera M, Cruz-Neto AP Tags: Comp Biochem Physiol A Mol Integr Physiol Source Type: research

Feeding in Eptatretus cirrhatus: effects on metabolism, gut structure and digestive processes, and the influence of post-prandial dissolved oxygen availability.
Abstract Hagfishes are characterised by feeding behaviours that may include long intervals between meals, and a hypoxic feeding environment inside decaying carrion. The effects of feeding on metabolism (oxygen consumption rate), gut mass and morphology (gut somatic index, gut epithelium mucosal thickness), and digestive function (maltase and peptidase activity) were examined in the New Zealand hagfish, Eptatretus cirrhatus. The influence of post-prandial hypoxia on oxygen consumption rate was also investigated to replicate the immersive feeding environment. Fed hagfish displayed a 1.9-fold increase in peak oxygen ...
Source: Comparative Biochemistry and Physiology. Part A, Molecular and integrative physiology. - December 7, 2018 Category: Physiology Authors: Glover CN, Weinrauch AM, Bynevelt S, Bucking C Tags: Comp Biochem Physiol A Mol Integr Physiol Source Type: research

Functional characterization of a cDNA encoding Piwi protein in Penaeus monodon and its potential roles in controlling transposon expression and spermatogenesis.
This study is aimed at cloning and characterization of a Piwi cDNA in the black tiger shrimp, Penaeus monodon. The cDNA encoding a Piwi protein of P. monodon (PmPiwi1) was obtained by rapid amplification of cDNA ends (RACE). The PmPiwi1 coding cDNA contains 2811 nt encoding a putative protein of 936 amino acids, and was specifically expressed in testis and ovary, suggesting its possible function in gametogenesis. RNAi experiment showed that suppression of PmPiwi1 expression led to a significant up-regulation of retrotransposon gypsy2 and DNA element transposon mariner in shrimp testis. Investigation of the function of Pm...
Source: Comparative Biochemistry and Physiology. Part A, Molecular and integrative physiology. - December 7, 2018 Category: Physiology Authors: Sukthaworn S, Panyim S, Udomkit A Tags: Comp Biochem Physiol A Mol Integr Physiol Source Type: research

Very high blood oxygen affinity and large Bohr shift differentiates the air-breathing siamese fighting fish (Betta splendens) from the closely related anabantoid the blue gourami (Trichopodus trichopterus).
Abstract The Siamese fighting fish, Betta splendens, and the blue gourami, Trichopodus trichopterus, are two closely related air-breathing anabantoid fishes. B. splendens is a sedentary facultative air breather frequenting often hypoxic waters, while T. trichopterus is a more active obligatory air-breather inhabiting better oxygenated waters. Despite their close taxonomic relationship, previous studies have shown inter-specific differences in both physiological and morphological plasticity. Consequently, we hypothesized that B. splendens would have the higher blood oxygen affinity characteristics typical of more h...
Source: Comparative Biochemistry and Physiology. Part A, Molecular and integrative physiology. - November 29, 2018 Category: Physiology Authors: Mendez-Sanchez JF, Burggren WW Tags: Comp Biochem Physiol A Mol Integr Physiol Source Type: research

Ontogeny of urea and ammonia transporters in mahi-mahi (Coryphaena hippurus) early life stages.
Abstract The mechanism(s) of ammonia and urea excretion in freshwater fish have received considerable attention; however, parallel investigations of seawater fish, specifically in the early life stages are scarce. The first objective of this study was to evaluate the patterns of ammonia and urea excretion in mahi-mahi (Coryphaena hippurus) up to 102  hours post fertilization (hpf). Similar to other teleosts, mahi embryos are ureotelic before hatch and gradually switch to being ammoniotelic around the time of hatch. The second objective was to characterize mRNA levels of ammonia transporters (Rhag, Rhbg, Rhc...
Source: Comparative Biochemistry and Physiology. Part A, Molecular and integrative physiology. - November 29, 2018 Category: Physiology Authors: Wang Y, Pasparakis C, Mager EM, Stieglitz JD, Benetti D, Grosell M Tags: Comp Biochem Physiol A Mol Integr Physiol Source Type: research

Loss of ion homeostasis is not the cause of chill coma or impaired dispersal in false codling moth Thaumatotibia leucotreta (Lepidoptera: Tortricidae).
Abstract Dispersal is a central requirement of a successful sterile insect release programme, but field-released false codling moth (FCM) typically suffer from poor dispersal ability, especially at low ambient temperatures. Here we test the hypothesis that poor activity and dispersal in FCM is caused by delayed or perturbed recovery of ion and/or water homeostasis after chilling for handling and transport prior to field release. Hemolymph and flight muscle were collected from two treatment groups at three time points that targeted thermal conditions above and below the chill coma induction threshold of ~ 6 °...
Source: Comparative Biochemistry and Physiology. Part A, Molecular and integrative physiology. - November 28, 2018 Category: Physiology Authors: Karsten M, Lebenzon JE, Sinclair BJ, Terblanche JS Tags: Comp Biochem Physiol A Mol Integr Physiol Source Type: research

Essential amino acids exhibit variable effects on protein degradation in rainbow trout (Oncorhynchus mykiss) primary myocytes.
Abstract The functional role of amino acids as regulators of protein degradation was investigated using primary myogenic precursor cell culture as in vitro model of rainbow trout white muscle. Seven-day old myocytes were starved of amino acids for two hours then exposed to media that contained amino acid treatments, during which protein degradation rates were analyzed over five hours by measuring cellular release of 3H-tyrosine. Increasing concentrations of essential amino acids (EAA) reduced protein degradation rates; this effect was dose-dependent within the physiological range found in plasma. Addition of leuci...
Source: Comparative Biochemistry and Physiology. Part A, Molecular and integrative physiology. - November 28, 2018 Category: Physiology Authors: Cleveland BM, Radler LM Tags: Comp Biochem Physiol A Mol Integr Physiol Source Type: research

Effects of dietary antioxidants and environmental stressors on immune function and condition in Lithobates (Rana) sylvaticus.
We examined the effects of dietary antioxidants (β-carotene and vitamin E) on the ability of Lithobates sylvaticus (wood frog) tadpoles to overcome the detrimental effects imposed by two common environmental stressors - exposure to the herbicide atrazine or infection by a pathogenic helminth parasite (Echinostoma trivolvis). Tadpoles which were fed high concentrations of either vitamin E or β-carotene had a greater immune response compared to those given trace diets of either compound as measured by circulating white blood cells and a phytohemaglutination assay (PHA). Similarly, tadpoles in the herbicide and para...
Source: Comparative Biochemistry and Physiology. Part A, Molecular and integrative physiology. - November 28, 2018 Category: Physiology Authors: Szuroczki D, Koprivnikar J, Baker RL Tags: Comp Biochem Physiol A Mol Integr Physiol Source Type: research

Characterization of a third ghrelin receptor, GHS-R3a, in channel catfish reveals novel expression patterns and a high affinity for homologous ligand.
Abstract A novel third channel catfish growth hormone secretagogue (ghrelin) receptor, GHS-R3a, gene was characterized. Identification and analysis of the genomic organization of channel catfish GHS-R3a revealed differences in exon/intron structure relative to the previously published GHS-R1a and GHS-R2a sequences. Amino acid sequence alignment of catfish GHS-R3a with -R1a and -R2a revealed 48 and 52% sequence identity, respectively. Phylogenetic analysis predicted a new clade of GHS-R3a receptors found only in fish, with representation in the teleost infradivisions Osteoglossomorpha, Clupeomorpha, and Euteleostei...
Source: Comparative Biochemistry and Physiology. Part A, Molecular and integrative physiology. - November 21, 2018 Category: Physiology Authors: Small BC, Quiniou SMA, Kaiya H, Bledsoe JW, Musungu B Tags: Comp Biochem Physiol A Mol Integr Physiol Source Type: research

Light intensity and suppression of nocturnal plasma melatonin in Arctic charr (Salvelinus alpinus).
Abstract The problem of early sexual maturation among farmed Arctic charr and other salmonids can be effectively reduced by 24 h light overwinter, provided it is bright enough to over-ride interference from the natural daylength cycle. To determine the threshold light intensity to suppress the nocturnal elevation of plasma melatonin, three groups of individually tagged fish (n = 26-28/group ca. 1040 g) were reared on 12 h light: 12 h dark (LD 12:12) and subjected to nighttime light intensities of either 50-65, 0.1-0.3 or 0 (control) lux for five months (November to April). Daytime light intensity was 7...
Source: Comparative Biochemistry and Physiology. Part A, Molecular and integrative physiology. - November 21, 2018 Category: Physiology Authors: Liu Q, Manning AJ, Duston J Tags: Comp Biochem Physiol A Mol Integr Physiol Source Type: research

Cloning and effects of fasting on the brain expression levels of appetite-regulators and reproductive hormones in glass catfish (Kryptopterus vitreolus).
In this study, we isolated cDNA encoding reproductive hormones (GnRH1, GnRH2) and appetite regulators (orexin, NPY, and CART) from glass catfish and examined their distribution in various tissues. All peptides had wide distributions across various brain and peripheral tissues, except CART, which was only present in brain. In order to assess whether limited energy supply affects these peptides, we examined the effects of fasting on their brain mRNA expression levels. Fasting increased the expression of both the orexigenic (i.e. orexin and NPY) and anorexigenic (i.e. CART) hormones, and decreased expression levels of GnRH1, ...
Source: Comparative Biochemistry and Physiology. Part A, Molecular and integrative physiology. - November 16, 2018 Category: Physiology Authors: London S, Volkoff H Tags: Comp Biochem Physiol A Mol Integr Physiol Source Type: research

Triploidy in white sturgeon (Acipenser transmontanus): Effects of acute stress and warm acclimation on physiological performance.
Abstract Previous studies have demonstrated reduced performance in triploid fish when reared under suboptimal conditions, which may be the result of a higher susceptibility to stressors when compared to diploids. The goal of this project was to investigate differences in the capacity of diploid (8 N) and triploid (12 N) white sturgeon, Acipenser transmontanus, to respond to both warm acclimation (6-weeks of acclimation to either 18 or 22 °C) and a subsequent acute stress (10-min low water stress). Following the 6-week acclimation, fish were sampled either before or following an acute low water stress. Bi...
Source: Comparative Biochemistry and Physiology. Part A, Molecular and integrative physiology. - November 14, 2018 Category: Physiology Authors: Leal MJ, Van Eenennaam JP, Schreier AD, Todgham AE Tags: Comp Biochem Physiol A Mol Integr Physiol Source Type: research

Interactive Effects of Osmotic Stress and Burrowing Activity on Protein Metabolism and Muscle Capacity in the Soft Shell Clam Mya Arenaria.
Sokolova IM Abstract Bioturbators such as sediment-dwelling marine bivalves are ecosystem engineers that enhance sediment-water exchange and benthic-pelagic coupling. In shallow coastal areas, bivalves are exposed to frequent disturbance and salinity stress that might negatively affect their activity and physiological performance; however, the mechanisms underlying these effects are not fully understood. We investigated the effects of osmotic stress (low and fluctuating salinity) and repeated burrowing on aerobic and contractile capacity of the foot muscle (assessed by the activity of succinate dehydrogenase and m...
Source: Comparative Biochemistry and Physiology. Part A, Molecular and integrative physiology. - November 13, 2018 Category: Physiology Authors: Haider F, Sokolov EP, Timm S, Hagemann M, Rayón EB, Marigómez I, Izagirre U, Sokolova IM Tags: Comp Biochem Physiol A Mol Integr Physiol Source Type: research

The use of photoperiods to provide year round spawning in lumpfish Cyclopterus lumpus.
ds P Abstract In order to provide year round spawning broodstock, lumpfish (initial size 746 g and 24.9 cm) were reared under four different photoperiod regimes from January 2017 to July 2018. One group was reared under simulated natural photoperiod (LDN, control group) for Tromsø (70°N). The second group was transferred to continuous light (LD240) on 30 January 2017 and reared at LD24:0 throughout the trial period. Two compressed and phase advanced photoperiods were also established. Both groups were moved from LDN to LD24:0 on 30 January 2017, and after that reared at compressed natural photoperio...
Source: Comparative Biochemistry and Physiology. Part A, Molecular and integrative physiology. - November 12, 2018 Category: Physiology Authors: Imsland AK, Hangstad TA, Jonassen TM, Stefansson SO, Nilsen TO, Hovgaard P, Elvegård TA, Lindberg KS, Mikalsen B, Urskog TC, Norberg B, Andersson E, Spetland F, Reynolds P Tags: Comp Biochem Physiol A Mol Integr Physiol Source Type: research