• Asian-Australasian Journal of Animal Sciences
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• v.26 no.1
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• pp.36-42
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• 2013

The average twin lambing rate of Bayanbulak sheep is 2% to 3%. However, a flock of sheep with a close genetic relationship and an average of 2 to 3 lambs per birth has been found recently. To determine the major genes controlling the prolificacy of the flock in the present study, the flock was designated A while 100 normal Bayanbulak sheep were randomly selected to comprise the control flock B. Ligase detection reaction method was applied to detect and analyze the 10 mutational loci of the 3 candidate prolificacy genes including bone morphogenetic protein type I receptors, bone morphogenetic protein 15, and growth differentiation factor 9. The 10 mutational loci are as follows: FecB locus of the BMPR-IB gene; $FecX^I$, $FecX^B$, $FecX^L$, $FecX^H$, $FecX^G$, and $FecX^R$ of the BMP15 gene; and G1, G8, and FecTT of the GDF9 gene. Two mutations including BMPR-IB/FecB and GDF9/G1 were found in Bayanbulak sheep. Independence test results of the two flocks demonstrate that the FecB locus has a significant effect on the lambing number of Bayanbulak sheep. However, the mutation frequency of the G1 locus in GDF9 is very low. Independence test results demonstrate that the GDF9 locus does not have a significant impact on the lambing performance of Bayanbulak sheep. Among the 10 detected loci, BMPR-IB/FecB is the major gene that influences the high lambing rate of Bayanbulak sheep.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.9
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• pp.1179-1183
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• 2011

The incidence of mutation in three loci of GDF9, BMP15 and BMP15-1B and their effects on litter sizes was evaluated in Baluchi sheep. Wild-type alleles were detected for BMP15 and BMP15-1B loci and all individuals were found to be as non-carriers for FecB and $FecX^G$ mutations but, a G to A nucleotide substitution was found in GDF9 locus. The frequency of $FecG^+$ (0.82) wild type allele was higher than the frequency of $FecG^l$ (0.18) mutant allele and the frequencies of $FecG^+/FecG^+$, $FecG^+/FecG^1$ and $FecG^1/FecG^1$ genotypes were 0.72, 0.20 and 0.08, respectively in GDF9 locus. The heterozygous ($FecG^+/FecG^1$) and homozygous ($FecG^+/FecG^+$) non-carrier ewes had 0.35 and 0.21 more lambs than the homozygous ($FecG^1/FecG^1$) carrier ewes, respectively (p<0.05). In addition to the finding of segregation of non-additive gene effect on litter size in the previous study in Baluchi sheep, these findings for the first time shows that the $FecG^1$ gene has a major effect on litter size in this breed.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.10
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• pp.1379-1382
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• 2005

High prolificacy in Garole sheep is due to existence of FecB mutation in an autosomal gene, bone morphogenetic protein receptor. The mutation enhances ovulation rate and in turn litter size in Garole sheep. Garole sires were crossed with non-prolific Malpura ewes with the aim to introduce prolificacy into Garole${\times}$Malpura (G${\times}$M) crosses through FecB introgression programme. In the present study, the effect of carrying booroola allele on litter size and live body weight was analyzed. The average litter size at birth was found to be 1.87 and 1.48 in the Garole and the G${\times}$M crosses, respectively. At weaning, 6-month, 9-month and 12-month of age, body weights were not affected by the presence of booroola allele (p>0.05); however, a significant effect (p<0.05) was found on body weight at birth in G${\times}$M crosses. In Garole sheep, no significant effect of FecB was observed on live weights in any age group. The interaction between the genetic group and the FecB genotype was also found to be non-significant.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.11
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• pp.1555-1559
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• 2003

The objective of the present study was to explore associations between five microsatellites linked to $Fec^B$ and $FecX^I$ genes and litter size in Small Tail Han sheep. The polymorphisms of five microsatellite loci, OarAE101, BM1329, BMS2508, TGLA54 and TGLA68 were detected in 244 ewes of Small Tail Han sheep. Analysis of association between three microsatellite loci (BMS2508, BM1329 and OarAE101) located in the 10 cM region covering the $Fec^B$ gene (Booroola gene) and litter size in Small Tail Han sheep indicated that BMS2508 had significant effect on litter size in the second parity (p<0.05), but no significant effect on litter size in the first parity (p>0.05), while the other two microsatellite loci had no significant effect on litter size in both the first and the second parity in Small Tail Han sheep (p>0.05). At microsatellite locus BMS2508, least squares means in the second parity of genotypes 101/111 and 99/109 were significantly higher than those of genotypes 99/99, 99/101, 99/111 and 99/115 (p<0.05); least squares mean in the second parity of genotype 101/111 was significantly higher than that of genotypes 109/111 and 111/111 (p<0.05). Results of this study also indicated that two microsatellite loci (TGLA54 and TGLA68) that confined the 28.7 cM region covering the $FecX^I$ gene (Inverdale gene) did not affect litter size in both the first and the second parity in Small Tail Han sheep significantly (p>0.05). The information found in the present study is very important for improving the reproductive performance in sheep breeds by marker assisted selection.