Signaling events regulating embryonic polarity and formation of the primitive streak in the chick embryo.

Signaling events regulating embryonic polarity and formation of the primitive streak in the chick embryo. Curr Top Dev Biol. 2020;136:85-111 Authors: Raffaelli A, Stern CD 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 amniotes including avians and non-rodent mammals, this enables an ability of the embryo to "regulate": a single multicellular embryo can give rise to more than one individual-monozygotic twins. Here we discuss the embryological, cellular, molecular and evolutionary underpinnings of gastrulation in avian embryos as a model amniote embryo. Many of these properties are shared by human embryos. PMID: 31959299 [PubMed - in process]
Source: Current Topics in Developmental Biology - Category: Biology Authors: Tags: Curr Top Dev Biol Source Type: research

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Authors: Al-Mnaser AA, Woodward MJ Abstract In vitro studies aimed at studying the mechanism of action of carvacrol and oregano as natural anti-bacterial agents to control multiple antibiotic-resistant avian pathogenic Escherichia coli (APEC) strain O23:H52 isolated from chicken were performed. Derivatives with increased minimum inhibitory concentrations (MIC) to the phytochemicals were selected after growing Escherichia coli (E. coli) strain O23:H52 at sub-lethal concentrations of carvacrol and oregano for a period of 60 days. Whole-genome sequencing (WGS) of two derivatives revealed a missense mutation in cadC an...
Source: Polish Journal of Microbiology - Category: Microbiology Tags: Pol J Microbiol Source Type: research
The objective of this study was to evaluate the prevalence and characteristics of avian-origin mcr-1-harbouring Escherichia coli in Shandong Province, China. During 2017—2018, a total of 668 non-duplicate E. coli isolates were separately collected from 8eight large intensive poultry farms in Shandong Province. Antimicrobial susceptibility testing for 10 antimicrobial agents commonly used in farms was performed on all E. coli isolates by the agar dilution method; the mobile colistin resistance gene (mcr-1) gene was screened by PCR, and mcr-1 positive isolates were PCR-screened for antimicrobial resistance genes and ty...
Source: Frontiers in Microbiology - Category: Microbiology Source Type: research
The emergence of human infection with avian influenza A(H7N9) virus was reported in Wenshan City, southwestern China in 2017. The study describes the epidemiological and virological features of the outbreak an...
Source: BMC Infectious Diseases - Category: Infectious Diseases Authors: Tags: Research article Source Type: research
Publication date: Available online 17 February 2020Source: Clinical Epidemiology and Global HealthAuthor(s): Krishna Prasad Acharya, Niran Adhikari, Muhammad TariqAbstractThe agro-climatic conditions, socio-economic situation, poor sanitation, low hygiene and health standards in Nepal are major contributing factors to the emergence of scrub typhus in Nepal. These outbreaks, along with poor diagnostic facilities, can lead to severe economic losses in a resource-limited country like Nepal. Diseases like avian influenza, leptospirosis, brucellosis, tuberculosis and rabies, that cause heavy socio-economic burden, have received...
Source: Clinical Epidemiology and Global Health - Category: Epidemiology Source Type: research
In this study, we show that OA-10, a newly synthesized triterpene out of 11 oleanane-type derivatives, exhibited significant antiviral activity against four different subtypes of IAV (H1N1, H5N1, H9N2 and H3N2) replications in A549 cell cultures with EC50 ranging from 6.7 to 19.6 μM and a negligible cytotoxicity (CC50 > 640 μM). It inhibited acid-induced hemolysis in a dose-dependent manner, with an IC50 of 26 µM, and had a weak inhibition on the adsorption of H5 HA to chicken erythrocytes at higher concentrations (≥40 µM). Surface plasmon resonance (SPR) analysis showed that...
Source: Viruses - Category: Virology Authors: Tags: Article Source Type: research
Czech authorities will cull nearly 140,000 turkey and chickens at a poultry farm where bird flu was detected, Agriculture Minister Miroslav Toman said on Monday.
Source: Reuters: Health - Category: Consumer Health News Tags: healthNews Source Type: news
In this study, we investigated the pathogenicity, replication and tropism of the low pathogenic avian influenza (LPAI) strain A/chicken/Belgium/460/2019(H3N1) in adult SPF layers and young SPF males. The inoculated hens showed 58% mortality and a 100% drop in egg production in the second week post inoculation. The high viral loads in the cloacal samples coincided with the period of the positive immunohistochemistry (IHC) of the oviduct, acute peritonitis and time of mortality, suggesting that the replication of H3N1 in the oviduct was a major component of the onset of clinical disease and increased level of excretion of th...
Source: Avian Pathology - Category: Pathology Authors: Tags: Avian Pathol Source Type: research
In this study, no difference was found between the presence of C.psittaci in pigeon droppings and season. In addition when the sequence analysis of the isolated samples were compared with the World database; all isolates were found to be 100% genotype B and 99% genotype E. In this study, the sequence analysis of the ompA gene of C.psittaci from domestic pigeon feces was determined for the first time in Turkey. Although the presence of C.psittaci in domestic pigeons is low, it is a zoonotic bacterium and is important for the public health. PMID: 32050885 [PubMed - in process]
Source: Mikrobiyoloji Bulteni - Category: Microbiology Tags: Mikrobiyol Bul Source Type: research
Publication date: April 2020Source: Molecular Immunology, Volume 120Author(s): Bal Krishan Sharma, Naresh Kumar Kakker, Sakshi Bhadouriya, Rajesh ChhabraAbstractAvian infectious bronchitis (IB) is an acute, highly infectious and contagious viral disease of chickens caused by avian infectious bronchitis virus (IBV) belonging to the genus Coronavirus and family Coronaviridae. It can affect all age groups of birds. The toll-like receptors (TLRs) are a major class of innate immune pattern recognition receptors that have a key role in immune response and defense against various infections.The TLRs are essential for initiation o...
Source: Molecular Immunology - Category: Allergy & Immunology Source Type: research
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