AUTHOR=Kochish Ivan I. , Titov Vladimir Yu. , Nikonov Ilya N. , Brazhnik Evgeni A. , Vorobyov Nikolai I. , Korenyuga Maxim V. , Myasnikova Olga V. , Dolgorukova Anna M. , Griffin Darren K. , Romanov Michael N. 

TITLE=Unraveling signatures of chicken genetic diversity and divergent selection in breed-specific patterns of early myogenesis, nitric oxide metabolism and post-hatch growth

JOURNAL=Frontiers in Genetics

VOLUME=13

YEAR=2023

URL=https://www.frontiersin.org/journals/genetics/articles/10.3389/fgene.2022.1092242

DOI=10.3389/fgene.2022.1092242

ISSN=1664-8021

ABSTRACT=<p><bold>Introduction:</bold> Due to long-term domestication, breeding and divergent selection, a vast genetic diversity in poultry currently exists, with various breeds being characterized by unique phenotypic and genetic features. Assuming that differences between chicken breeds divergently selected for economically and culturally important traits manifest as early as possible in development and growth stages, we aimed to explore breed-specific patterns and interrelations of embryo myogenesis, nitric oxide (NO) metabolism and post-hatch growth rate (GR).</p><p><bold>Methods:</bold> These characteristics were explored in eight breeds of different utility types (meat-type, dual purpose, egg-type, game, and fancy) by incubating 70 fertile eggs per breed. To screen the differential expression of seven key myogenesis associated genes (<italic>MSTN</italic>, <italic>GHR</italic>, <italic>MEF2C</italic>, <italic>MYOD1</italic>, <italic>MYOG</italic>, <italic>MYH1</italic>, and <italic>MYF5</italic>), quantitative real-time PCR was used.</p><p><bold>Results:</bold> We found that myogenesis associated genes expressed in the breast and thigh muscles in a coordinated manner showing breed specificity as a genetic diversity signature among the breeds studied. Notably, coordinated (“accord”) expression patterns of <italic>MSTN</italic>, <italic>GHR</italic>, and <italic>MEFC2</italic> were observed both in the breast and thigh muscles. Also, associated expression vectors were identified for <italic>MYOG</italic> and <italic>MYOD1</italic> in the breast muscles and for <italic>MYOG</italic> and <italic>MYF5</italic> genes in the thigh muscles. Indices of NO oxidation and post-hatch growth were generally concordant with utility types of breeds, with meat-types breeds demonstrating higher NO oxidation levels and greater GR values as compared to egg-type, dual purpose, game and fancy breeds.</p><p><bold>Discussion:</bold> The results of this study suggest that differences in early myogenesis, NO metabolism and post-hatch growth are breed-specific; they appropriately reflect genetic diversity and accurately capture the evolutionary history of divergently selected chicken breeds.</p>