Genetic Variability of Indels in the Prolactin and Dopamine Receptor D2 Genes and Their Association with the Yield of Allanto-Amniotic Fluid in Russian White Laying Hens

Michael ROMANOV,Anna A. KRUTIKOVA,Olga V. MITROFANOVA,Andrei A. KUDINOV,Nikolai V. PLESHANOV,Mikhail G. SMARAGDOV,Olga İ. STANISHEVSKAYA,Elena S. FEDOROVA,Natalia V. DEMENTIEVA,Valeriy P. TERLETSKY

doi:10.15832/ankutbd.483561

Michael ROMANOV, Anna A. KRUTIKOVA + Show 8 more

Open Access

https://doi.org/10.15832/ankutbd.483561

Copy DOI

Abstract

Currently, there is virtually no information on genetic factors affecting the yield of allanto-amniotic fluid, which is the raw material for the production of human and animal vaccines. Association studies including this trait are beneficial for increasing productivity of a biotechnological line of chickens used for the production of ‘Clean Eggs’. We examined here a population of the Russian White breed for the effects of indels in the prolactin (PRL) and dopamine receptor D2 (DRD2) genes on the yield of extraembryonic fluid (YEF) and embryo weight at 12.5 days of development. A 24-bp insertion in the 5' flanking region of the PRL gene significantly (P<0.01) increases YEF in the embryos. The heterozygous embryos contained the highest YEF (9.6 mL) than that of the homozygous insertion (9.4 mL) and deletion embryos (8.4 mL). We also found a significant association (P<0.001) between the PRL genotypes and egg weight (EW). The results of the present study suggest a significant association between the PRL gene variation and quantitative traits in the Russian White chickens, contributing to a long-term programme on the effective use of the genetic potential of Russian gene pool breeds and populations of chickens.

Highlights

Extraembryonic fluid obtained from chicken eggs is beneficial in the production of human and animal vaccines against viruses, and in pharmaceutical studies
The prolactin (PRL) and dopamine receptor D2 (DRD2) genes have been suggested among the most promising candidate genes, allelic variants of which could be associated with the production traits in poultry
PRL is considered to be more associated with egg production traits, as it is believed that this hormone determines the broody instinct in the body of laying hens (Romanov 2001; Reddy et al 2002, 2007; Wang et al 2009; Wang et al 2011)

Summary

Introduction

Extraembryonic fluid obtained from chicken eggs is beneficial in the production of human and animal vaccines against viruses, and in pharmaceutical studies. Variant detection and studies of association between candidate genes or genetic markers and economically important traits have been broadly attempted in commercial poultry populations (Dunn et al 2004) and native breeds (Li et al 2008; Guo et al 2016). Application of this approach in non-commercial, germplasm poultry populations has been complicated by their small size and the need to maintain their genetic diversity. An efficiency of using the PRL gene was studied as a candidate gene and a marker in the selection programme of Silkie chicken, but no significant associations between genetic variation at this gene locus and performance traits were identified (Wada et al 2008; Rowshan et al 2012)

Methods

Results

Conclusion