Effects of the FecL major gene in the Lacaune meat sheep population
Effects of the FecL major gene in the Lacaune meat sheep population
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DOI：
10.1186/1297-9686-46-48
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发表时间：
2014-08-12
影响因子：
4.1
通讯作者：
Bodin, Loys
中科院分区：
文献类型：
--
作者：
Martin, Pauline;Raoul, Jerome;Bodin, Loys
背景：主要繁殖基因FecL于1998年首次在拉库恩绵羊品种Ovi-Test中被发现。一些研究估计了这种基因对繁殖能力的影响，但数据很少。2010年，Ovi-Test合作社开始对所有替代母羊羔羊进行FecL基因分型。由于现在有大量的基因分型数据，基因对产仔数和其他相关性状的影响可以更准确地估计出来。方法：选取2010年以来5775只母羊基因分型和2002年以来1025只母羊基因分型。性能和系谱从法国国家数据库中提取，用于遗传评估和研究。利用ASReml软件建立线性或阈值遗传动物模型，分析该基因对不同性状的影响。结果：母羊种群中纯合子野生型母羊（++）占71%，FecL突变型母羊（L+）占27%，纯合子突变型母羊（LL）占2%。平均而言，L +母羊比++母羊每只产羔多0.5只。FecL基因不仅影响平均产仔数，而且影响产仔数的变异，++母羊产仔数低于L +母羊。L +母羊授精后的受精率高于++母羊。++产羔比L +产羔重（+ 300 g）， ++产羔的死亡率低于L +产羔。此外，当忽略该主要基因的存在时，估计繁殖值的偏差被量化。结论：FecL基因对繁殖能力的影响更准确，我们发现该基因既影响产仔数的平均值，也影响产仔数和其他性状的变异。本文还表明，在繁殖力的遗传评价中忽略该主基因的存在会导致对多基因育种价值的高估。
Background: The major prolificacy gene FecL was first described in the Lacaune sheep meat breed Ovi-Test in 1998. A few studies estimated the effect of this gene on prolificacy but little data is available. In 2010, the Ovi-Test cooperative started genotyping FecL in all of their replacement ewe lambs. Thanks to the large amount of genotyping data that is available now, gene effects on litter size and other relevant traits can be estimated more accurately.Methods: Our study included 5775 ewes genotyped since 2010 and 1025 sires genotyped since 2002. Performances and pedigrees were extracted from the French national database for genetic evaluation and research. Analysis of the effect of the gene on different traits was based on linear or threshold genetic animal models using the ASReml software.Results: The female population was composed of 71% homozygous wild type ewes (++), 27% heterozygous ewes for the FecL mutation (L+) and 2% homozygous mutant (LL) ewes. On average, L + ewes produced 0.5 more lambs per lambing than ++ ewes. The FecL gene not only affected the mean litter size but also its variability, which was lower for ++ than for L + ewes. Fertility after insemination was higher for L + ewes than for ++ ewes. Lambs from ++ dams were heavier (+ 300 g) than the lambs of L + dams and the mortality of twin lambs born from ++ dams was lower than those from L + dams. In addition, bias in estimated breeding values for prolificacy when ignoring the existence of this major gene was quantified.Conclusions: The effect of the FecL gene on prolificacy was estimated more accurately and we show that this gene affects both the mean and the variability of litter size and other traits. This paper also shows that ignoring the existence of this major gene in genetic evaluation of prolificacy can lead to a large overestimation of polygenic breeding values.