title: Allelic and genotypic frequencies in polymorphic Booroola fecundity gene and their association with multiple birth and postnatal growth in Chhotanagpuri sheep.
abstract: OBJECTIVE
  Chhotanagpuri breed of sheep reared for mutton in Jharkhand, India, having problem of low litter size and body weight. The response of genetic improvement for traits with low heritability through traditional selection method is time-consuming. Therefore, marker-assisted selection based on a polymorphism study of suitable candidate gene can response quickly. Thus, this study was aimed at identification of different allelic and genotypic frequencies of Booroola fecundity (FecB) gene and its association with multiple birth and postnatal growth in Chhotanagpuri sheep.
  
  
  METHODS
  DNA isolation and gene-specific amplification ofFecBgene was performed from blood samples of from 92 Chhotanagpuri lambs maintained under similar feeding and management conditions. Custom nucleotide sequencing and single-strand conformational polymorphism analysis were performed to identify different genotypes with respect to the target gene. Statistical analysis was performed for determination of allelic and genotypic frequencies ofFecBgene polymorphisms and its association with multiple birth and postnatal growth of lambs from birth to 52 weeks age.
  
  
  RESULTS
  "AA," "AB," and "BB" genotypes were found at locus-1 as it is polymorphic forFecBgene while locus-2 was found to be monomorphic forFecBgene. Higher frequency of "A" allele at locus-1 was found in single born lambs, whereas "B" allele was predominant among multiple born lambs. The lambs having "BB" genotype weighed significantly (p≤0.01) heavier than those of "AB" and "AA" genotype at 52 weeks of age.
  
  
  CONCLUSIONS
  "BB" genotype has emerged as favored genotype for multiple births and better growth indicator. Therefore, homozygous lambs for "B" allele should be selected and utilized in breeding program for better growth rate.
authors.affiliation: Department of Animal Breeding and Genetics, Ranchi Veterinary College, Birsa Agricultural University, Kanke, Ranchi, Jharkhand, India.
authors.forename: Thanesh
authors.initials: T
authors.lastname: Oraon
authors.affiliation: Department of Animal Breeding and Genetics, Ranchi Veterinary College, Birsa Agricultural University, Kanke, Ranchi, Jharkhand, India.
authors.forename: D K
authors.initials: DK
authors.lastname: Singh
authors.affiliation: Department of Veterinary Biochemistry, Ranchi Veterinary College, Birsa Agricultural University, Kanke, Ranchi, Jharkhand, India.
authors.forename: Mayukh
authors.initials: M
authors.lastname: Ghosh
authors.affiliation: Department of Animal Nutrition, Ranchi Veterinary College, Birsa Agricultural University, Kanke, Ranchi, Jharkhand, India.
authors.forename: S S
authors.initials: SS
authors.lastname: Kullu
authors.affiliation: Department of Veterinary Physiology, Veterinary College, Pookode, Lakkidi, Kerala, India.
authors.forename: Rajesh
authors.initials: R
authors.lastname: Kumar
authors.affiliation: Department of Animal Breeding and Genetics, Ranchi Veterinary College, Birsa Agricultural University, Kanke, Ranchi, Jharkhand, India.
authors.forename: L B
authors.initials: LB
authors.lastname: Singh
keywords: Booroola fecundity gene; Chhotanagpuri sheep; body growth; multiple births; single-strand conformational polymorphism