SCREENING FOR POLYMORPHISMS IN LITTER SIZE TRAIT ASSOCIATED GENES IN GOATS OF BANGLADESH

Abstract

A study was carried out to screen the goats of Bangladesh for the presence of polymorphisms in three prolificacy genes (GDF9, BMP15 and CDH26) and to assess the association between polymorphisms and litter size. A total of 139 animals were screened comprising of 63 Black Bengal, 40 Jamnapari and 36 Crossbred goats.The selected animals had variable litter size and parity. Blood samples were collected from jugular vein using sterile vacutainer pack. Genomic DNA was extracted from collected blood samples using commercial DNA extraction kit. The fragments of exon 2 of BMP15, exon 2 of GDF9 and exon 8 of CDH26 gene were amplified using Polymerase Chain Reaction (PCR). PCR products were sequenced using DNASanger sequencing method. Association analysis for identified polymorphisms and litter size was done using a generalized linear model. Phylogenetic analysis was also performed to explore the genetic diversity of different goats.Ten single nucleotide polymorphisms (SNPs) were identified of which four (g.818C˃T, g.1073G˃A, g.1189G˃A and g.1330G˃T) were in GDF9 gene, three (g.616G˃T, g.735G˃A and g.811G˃A) were in BMP15 gene and three (g.975C˃T, g.1064G˃A and g.1035-1036CA˃TG) were in CDH26 gene.Among them, seven SNPs were novel and three SNPs were known based on extensive literature search.The association analysis showed 818C>T and 1330G>T loci of GDF9 gene recorded with a significantly (p<0.05) higher litter size. However, the effect of breed and parity was significant (p<0.05) on litter size in these three Bangladeshi goats. These results preliminarily showed that the GDF9 gene might be a major gene that influences prolificacy of Bangladeshi goat.This study provides basic additional molecular data that would be useful for future researchon thelitter size trait in goats of Bangladesh. This attempt for goat fecundity research would also be paveda scientific basis for the conservation and utilization of goat genetic resources.