BioProject

Authors: Keane, OM1, Hanrahan, JP2, Tosser-Klopp, G3, Fabre, S3, Demars and Bodin, L3 Affiliations: 1Teagasc Animal & Bioscience Dept, Grange, Co. More...

Authors: Keane, OM1, Hanrahan, JP2, Tosser-Klopp, G3, Fabre, S3, Demars and Bodin, L3 Affiliations: 1Teagasc Animal & Bioscience Dept, Grange, Co. Meath, Ireland; 2Teagasc, Athenry, Co. Galway, Ireland; 3INRA – GenPhySE, BP 52627, 31326 Castanet-Tolosan, France; orla.keane@teagasc.ie Abstract (EAAP 2013, Nantes, France): Cambridge sheep are characterised by high ovulation rate with extreme variation between individuals, consistent with segregation of major genes controlling ovulation rate. Ovarian hypoplasia with resultant female sterility is also found in the Cambridge breed and polymorphisms in both GDF9 and BMP15 have been shown to be associated with increased ovulation rate in heterozygous carriers and sterility in homozygous carriers in this breed. Recent data has provided evidence of a third major gene controlling ovulation rate in the Cambridge breed. The inheritance pattern suggests that this gene is autosomal and unlinked to GDF9 or BMP15. Mapping this gene was one of the goals of the EU-funded project 3SR, Sustainable Solutions for Small Ruminants. Sterile ewes with ovarian hypoplasia, where sterility cannot be explained by GDF9 or BMP15 polymorphisms, were identified along with their parents and 26 animals were genotyped using the Illumina ovine 50 Beadchip. Homozygosity mapping was used to identify regions of homozygosity in the unexplained sterile animals that were heterozygous in their carrier parents. Two regions of homozygosity were mapped to OAR 2 and OAR 8. The coding region of 2 candidate genes in the region of interest on OAR2, ACVR1 and ACVR1C were sequenced but no polymorphisms associated with sterility were identified. Whole genome sequencing of 7 animals has been performed in order to refine the region of interest and fine map the major gene regulating ovulation rate. Lambing percentage is a major driver of profitability in a sheep enterprise. The identification of a major gene controlling ovulation rate and hence litter size is a viable option to increase lambing percentage via genetic testing and selection. These results have been obtained through the EC-funded FP7 Project 3SR-245140 Sequencing and bioinformatics analysis have been performed by: Sarry, J, Bouchez, O, Senin, P and Bardou, P (INRA, BP 52627, 31326 Castanet-Tolosan, France) Less...