Bird eyes distinguish summer from winter: Retinal response to acute photoperiod change in the night-migratory redheaded bunting

Publication date: Available online 26 July 2015 Source:Journal of Chemical Neuroanatomy Author(s): Gaurav Majumdar, Garima Yadav, Sangeeta Rani, Vinod Kumar Eyes are the part of the circadian timekeeping system but not involved in the photoperiod regulated seasonal physiology in songbirds. Herein, two experiments tested whether eyes detect and respond to seasonal change in the photoperiod environment, by examining gene and protein expressions in the retinas of redheaded buntings exposed to a single long day (LD, 16L:8D), with controls on short days (SD, 8L:16D). In the first experiment, mRNA expression of genes implicated in the light perception (opsins, rhodopsin, neuropsin, melanopsin, peropsin) and photoperiod induction (eya3, tsh-β, dio2, dio3) was measured at hours 15 and 19 (hour 0=light on) on the first long day. There was a significant increase in the eya3, tsh-β and dio2 mRNA expression, albeit with a temporal difference, and decrease in the neuropsin mRNA expression in buntings on the first long day. There was no change in the dio3, rhodopsin, melanopsin and peropsin mRNA expressions on exposure to long days. The second experiment immunohistochemically examined the eya3, tsh-β and rhodopsin peptide expressions. eya3 was expressed in both light conditions, but with a significant higher levels in the retinal photoreceptor layer (PRL) under LD, as compared to SD. Similarly, tsh-β was expressed in the PRL of LD retinas only. Rhodopsin levels we...
Source: Journal of Chemical Neuroanatomy - Category: Neuroscience Source Type: research

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Publication date: 25 January 2020Source: New Scientist, Volume 245, Issue 3266Author(s):
Source: New Scientist - Category: Science Source Type: research
Authors: Thomas PG, Shubina M, Balachandran S Abstract Influenza A viruses (IAV) are members of the Orthomyxoviridae family of negative-sense RNA viruses. The greatest diversity of IAV strains is found in aquatic birds, but a subset of strains infects other avian as well as mammalian species, including humans. In aquatic birds, infection is largely restricted to the gastrointestinal tract and spread is through feces, while in humans and other mammals, respiratory epithelial cells are the primary sites supporting productive replication and transmission. IAV triggers the death of most cell types in which it replicate...
Source: Current Topics in Microbiology and Immunology - Category: Microbiology Tags: Curr Top Microbiol Immunol Source Type: research
AbstractH9N2 avian influenza viruses sporadically infect humans worldwide. These viruses have also contributed internal genes to H5N1, H5N6, H7N9, and H10N8 viruses, which have been isolated from humans with infections and are a substantial public health threat. To investigate the potential pathogenic mechanism of the H9N2 virus, we performed serial lung-to-lung passage of an avirulent H9N2 avian influenza virus (A/Chicken/Shandong/416/2016 [SD/416]) in mice to increase the pathogenicity of this virus. We generated a mouse-adapted (MA) virus that exhibited increased viral titers in the lungs, caused severe lung damage in m...
Source: Medical Microbiology and Immunology - Category: Microbiology Source Type: research
In conclusion, children younger than 5 years, especially boys, were vulnerable groups for pandemic influenza, presenting as a mild disease with low mortality and few complications. Most of the affected children with influenza did not have important risk factors such as asthma and obesity, highlighted by other authors as significant risk factors. PMID: 31969753 [PubMed - in process]
Source: Acta Clinica Croatica - Category: General Medicine Tags: Acta Clin Croat Source Type: research
In this study, we investigated whether heritable differences in colonization of inbred chicken lines by Campylobacter jejuni are associated with differences in caecal microbiota. We performed homologous and heterologous caecal microbiota transplants between line 61 (resistant) and line N (susceptible), by orally administering caecal contents collected from 3-week-old donors to day-of-hatch chicks. Recipient birds were challenged (day 21) with C. jejuni 11168H. In birds given homologous microbiota, the differential resistance of lines to C. jejuni colonization was reproduced. Contrary to our hypothesis, transfer of caecal m...
Source: Applied and Environmental Microbiology - Category: Microbiology Authors: Tags: Appl Environ Microbiol Source Type: research
AbstractNewcastle disease (ND), caused by virulentAvian avulavirus 1 (AAvV 1), affects variety of avian species around the globe. Several AAvV 1 viruses of different genotypes have recently emerged with varying clinical impacts on their susceptible hosts. Although experimental infection with velogenic and mesogenic strains in chickens and pigeons is well-studied, nevertheless, there exists a paucity of data for comparative variations in serum biochemistry profile of susceptible hosts upon challenge with isolates of varying pathogenicities. With this background, a comparative assessment of a range of serum biochemical param...
Source: Tropical Animal Health and Production - Category: Veterinary Research Source Type: research
PHE has updated their advice about travelling to Wuhan in China in light of the reported 217 cases of known infections with this virus. WHO state there is now evidence of limited human-to-human transmission.
Source: Current Awareness Service for Health (CASH) - Category: Consumer Health News Source Type: news
Abstract The avian embryo is a key experimental model system for early development of amniotes. One key difference with invertebrates and "lower" vertebrates like fish and amphibians is that amniotes do not rely so heavily on maternal messages because the zygotic genome is activated very early. Early development also involves considerable growth in volume and mass of the embryo, with cell cycles that include G1 and G2 phases from very early cleavage. The very early maternal to zygotic transition also allows the embryo to establish its own polarity without relying heavily on maternal determinants. In many...
Source: Current Topics in Developmental Biology - Category: Biology Authors: Tags: Curr Top Dev Biol Source Type: research
Publication date: Available online 22 January 2020Source: Regulatory Toxicology and PharmacologyAuthor(s): Diana Temple, Timothy Springer, Sean Gallagher, Gunther du Hoffmann, James R. WheelerAbstractThe European Chemical Agency and European Food Safety Authority recommend that gross pathology findings, from avian reproduction studies, be used to support assessment of potential endocrine disrupting properties of active pesticidal and biocidal substances. In open literature, little information is available on the utility of gross pathology data for informing endocrine evaluations. Here the gross pathology data from historic...
Source: Regulatory Toxicology and Pharmacology - Category: Toxicology Source Type: research
Tissue morphogenesis is driven by local cellular deformations that are powered by contractile actomyosin networks. How localized forces are transmitted across tissues to shape them at a mesoscopic scale is still unclear. Analyzing gastrulation in entire avian embryos, we show that it is driven by the graded contraction of a large-scale supracellular actomyosin ring at the margin between the embryonic and extraembryonic territories. The propagation of these forces is enabled by a fluid-like response of the epithelial embryonic disk, which depends on cell division. A simple model of fluid motion entrained by a tensile ring q...
Source: ScienceNOW - Category: Science Authors: Tags: Biochemistry, Development reports Source Type: news
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