Identification Of Polymorphism And Epigenetic Modification Of Partial Promoter Of Acacb Gene Vis A Vis Effect Of Polymorphism On Egg Production And Quality Traits In Layers

Abstract

Poultry eggs are rich source of inexpensive, high-quality protein, vitamins namely newlineA, B2, B6, B12, D, E and K, minerals like zinc, iron selenium, and copper etc. Egg yolk newlinecontains more calories and fat. In the recent past, there is demand for consumption of food newlinesources of poly unsaturated fatty acids like dodecanoic acid, nonadecanoic acid, newlinemyristoleic acid, alpha linoleic acid and omega-3 fatty acids. The fatty acid composition newlinedepends on type of diet and genetic composition. Among the candidate genes, the acetylcoenzyme newlineA carboxylase beta (ACACB) is a candidate gene that can influence fatty acid newlinecomposition. Perusal of literature revealed that the identification of partial promoter of newlineACACB gene was not done in chicken. Hence the present study is aimed at identification of newlinepartial promoter region, genetic polymorphism, gene expression and epigenetic regulation newlineof ACACB gene in chicken. Further, the study also aimed at unraveling the association of newlinethe genetic polymorphism with body weight, egg production and egg quality traits in the newlinetwo-layer lines, IWI and IWK. newlineThe study could successfully predict the minimal promoter region which is in the newlineupstream 0.5 kb region. The region included certain transcription factors like CEBP, newlineCOUP, HNF4, PPARA, SREBP1, and T3R which are known to be involved in lipid newlinemetabolism. The minimal promoter region could potentially translate the gene in chicken embryo fibroblasts. Further, the minimal promoter region is polymorphic with 12 newlinehaplotypes and 18 haplogroups based on SSCP analysis. The haplotype h5 is least frequent newlinein both IWI and IWK lines while h11 haplotype is most frequent in IWI line and h4 newlinehaplotype is the most frequent one in IWK line. Sequencing of the haplotypes revealed newlineindels and substitutes in these haplotypes. The h8h8 haplogroup is associated with higher newlinebody weight at 8th, 16th and 20th week in IWI line. The haplogroup h12h12 is strongly newlineassociated with higher egg production in IWI line up to 52 weeks of age. The egg weight newlinedidn t vary significantly within th