<abstract xmlns="http://www.w3.org/1999/xhtml">Two mutations affecting the ovulation rate and litter size are segregating in Olkuska sheep population, FecXO in the BMP15 gene, and the G7 site mutation in GDF9 gene. Homozygous carriers of both mutations are hyperprolific, contrary to the sterility observed in homozygous carriers of most other BMP15 and GDF9 mutations. The objective of this study was to assess frequency and phenotypic effects of both mutations. Blood samples were obtained from 740 individuals, 111 rams and 629 ewes, out of which 91 rams and 561 ewes were successfully genotyped for the BMP15 and GDF9 loci. The reproductive performance included a number of lambs born/born alive and a number of lambs reared until 60 days of age, and for a subset of ewe ovulation rates. The study proved a high frequency of the FecXO mutation in two flocks that have been selected for many years for increased litter size (0.7–1.0 in breeding ewes and rams respectively), and a moderate frequency in another 19 private flocks (0.4–0.5). The frequency of the GDF9 mutation was low, with only 50 sheep out of 312 genotyped being carriers of the GDF9/G7 mutation, including three homozygous carriers. The FecXO mutation in the BMP15 had a significant effect on both litter size and the ovulation rate. The single copy in heterozygous carriers increased litter size by 0.255 (0.063), while the effect of two copies in homozygous genotypes was +0.874 (0.081) lambs born. Due to the low frequency of the GDF9 mutation, it can only be preliminarily concluded that litter size has been increased in double carriers of both the BM15 and GDF9 mutation, which may suggest their additive interaction. The positive effect of both mutations supports their direct use in selection programmes.</abstract>

Two mutations affecting the ovulation rate and litter size are segregating in Olkuska sheep population, FecXO in the BMP15 gene, and the G7 site mutation in GDF9 gene. Homozygous carriers of both mutations are hyperprolific, contrary to the sterility observed in homozygous carriers of most other BMP15 and GDF9 mutations. The objective of this study was to assess frequency and phenotypic effects of both mutations. Blood samples were obtained from 740 individuals, 111 rams and 629 ewes, out of which 91 rams and 561 ewes were successfully genotyped for the BMP15 and GDF9 loci. The reproductive performance included a number of lambs born/born alive and a number of lambs reared until 60 days of age, and for a subset of ewe ovulation rates. The study proved a high frequency of the FecXO mutation in two flocks that have been selected for many years for increased litter size (0.7–1.0 in breeding ewes and rams respectively), and a moderate frequency in another 19 private flocks (0.4–0.5). The frequency of the GDF9 mutation was low, with only 50 sheep out of 312 genotyped being carriers of the GDF9/G7 mutation, including three homozygous carriers. The FecXO mutation in the BMP15 had a significant effect on both litter size and the ovulation rate. The single copy in heterozygous carriers increased litter size by 0.255 (0.063), while the effect of two copies in homozygous genotypes was +0.874 (0.081) lambs born. Due to the low frequency of the GDF9 mutation, it can only be preliminarily concluded that litter size has been increased in double carriers of both the BM15 and GDF9 mutation, which may suggest their additive interaction. The positive effect of both mutations supports their direct use in selection programmes.

Frequency of BMP15 and GDF9 mutations increasing litter size and their phenotypic effects in Olkuska sheep population

Department of Animal Genetics and Conservation, Institute of Animal Sciences

Department of Animal Biotechnology, Faculty of Animal Science

Department of Physiology and Endocrinology, Faculty of Animal Science

Annals of Animal Science

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Two mutations affecting the ovulation rate and litter size are segregating in Olkuska sheep population, FecXO in the BMP15 gene, and the G7 site mutation in...

Frequency of BMP15 and GDF9 mutations increasing litter size and their phenotypic effects in Olkuska sheep population

Publié en ligne: 29 janv. 2021

Pages: 89 - 108

Reçu: 13 nov. 2019

Accepté: 14 mai 2020

DOI: https://doi.org/10.2478/aoas-2020-0054

Mots clés
litter size, sheep, major genes, ovulation rate

© 2020 Wioleta Drobik-Czwarno et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Frequency of BMP15 and GDF9 mutations increasing litter size and their phenotypic effects in Olkuska sheep population

Publié en ligne: 29 janv. 2021

Pages: 89 - 108

Reçu: 13 nov. 2019

Accepté: 14 mai 2020

DOI: https://doi.org/10.2478/aoas-2020-0054

Mots cléslitter size, sheep, major genes, ovulation rate

© 2020 Wioleta Drobik-Czwarno et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Mots clés
litter size, sheep, major genes, ovulation rate