FecX Bar a Novel BMP15 mutation responsible for prolificacy and female sterility in Tunisian Barbarine Sheep

Abstract

BackgroundNaturally occurring mutations in growth and differentiation factor 9 (GDF9) or bone morphogenetic protein 15 (BMP15) genes are associated with increased ovulation rate (OR) and litter size (LS) but also sterility. Observing the Tunisian Barbarine ewes of the “W” flock selected for improved prolificacy, we found prolific and infertile ewes with streaky ovaries. Blood genomic DNA was extracted from a subset of low-ovulating, prolific and infertile ewes of the “W” flock, and the entire coding sequences of GDF9 and BMP15 were sequenced.ResultsWe evidenced a novel polymorphism in the exon 1 of the BMP15 gene associated with increased prolificacy and sterility. This novel mutation called FecX Bar is a composite polymorphism associating a single nucleotide substitution (c.301G > T), a 3 bp deletion (c.302_304delCTA) and a C insertion (c.310insC) in the ovine BMP15 cDNA leading to a frame shift at protein position 101. Calculated in the “W” flock, the FecX Bar allele increased OR by 0.7 ova and LS by 0.3 lambs (p = 0.08). As for already identified mutations, homozygous females carrying FecX Bar exhibited streaky ovaries with a blockade at the primary stage of folliculogenesis as shown by histochemistry.ConclusionsOur investigation demonstrates a new mutation in the BMP15 gene providing a valuable genetic tool to control fecundity in Tunisian Barbarine, usable for diffusion program into conventional flocks looking for prolificacy improvement.

Genome-Wide Association Study Reveals Candidate Genes for Litter Size Traits in Pelibuey Sheep

“…The single-nucleotide polymorphisms (SNPs) identified in these genes were shown to be associated with an increase of ovulation rate (OR) and litter size [14]. Nine SNPs were evidenced in the gene BMP15 such as FecX I , FecX H [6], FecX B , FecX G [10], FecX L [14], FecX2 W [15], FecX O , FecX Gr [16], FecX Bar [17], and deletion of 17 base pairs in FecX R [9]. In the GDF9 gene, eleven point mutations were reported: G1, G2, G3, G4, G5, G6, G7, G8 [10], FecT T [18], FecG E [19], and FecG WNS [20].…”

Novel Variants in GDF9 Gene Affect Promoter Activity and Litter Size in Mongolia Sheep

“…The FecB B mutation was found in Booroola Merino [1][2][3], Javanese [8], small-tailed Han [9], Hu [10], Garole and Kendrapada [11], Kalehkoohi [12], and Wadi sheep [13]. Mutations in BMP15 were detected in Romney and Inverdale (FecX H and FecX I ) [4], Cambridge and Belclare (FecX B and FecX G ) [5], Lacaune (FecX L ) [14], Rasa Aragonesa (FecX R ) [15], Olkuska (FecX O ) and Givette (FecX Gr ) [16], and Barbarine sheep (FecX Bar ) [17]. The GDF9 mutations were observed in Cambridge and Cambridge (FecG H ) [5], Thoka (FecG T ) [18], Santa Ines (FecG E ) [19], Baluchi (FecG 1 ) [20], Norwegian White Sheep, Finn Ile de France sheep and Belclare (FecG F ) [21,22], Ile de France (FecG V ) [23], and Araucana creole sheep (FecG A ) [24].…”

Research Article How efficiently Genome-Wide Association Studies (GWAS) identify prolificity-determining genes in sheep

“…There have been recent reports of high prolificacy sheep in commercial flocks worldwide (Mullen & Hanrahan, 2014;Souza et al, 2014;Lassoued et al, 2017). Traditionally, the high prolificacy sheep are tested against single nucleotide polimorphism (SNPs) of known mutation, if the phenotype does not fit an earlier studied genotyping system, the search for a new gene of interest needs to be investigated.…”