Ibrahim Adel H M
Department of Animal Breeding, Desert Research Center, Cairo, Egypt.
Vet World. 2021 Feb;14(2):515-522. doi: 10.14202/vetworld.2021.515-522. Epub 2021 Feb 26.
Marker-assisted selection has many advantages over conventional selection in animal breeding. The candidate gene approach has been applied to identify genetic markers associated with economically important traits in livestock. This study was established to investigate variation in the hormone-sensitive lipase () and leptin receptor () genes, and their association with growth traits in Barki lambs.
Records for birth weight (BW), pre-weaning average daily gain (ADG1), weaning weight (WW), post-weaning average daily gain (ADG2), and marketing weight (MW) were obtained from 247 Barki lambs. Polymerase chain reaction-single-stranded conformational polymorphism analyses were used to detect variation in exon 9 of and exon 19 of . General linear models were used to test for associations between the variation in ovine and , and growth traits.
The SSCP banding patterns for showed three variants (, , and ), which contained two nucleotide-sequence differences (c.1865C>T and c.2038T>C). Two SSCP banding patterns ( and ) were observed for and these contained two nucleotide-sequence differences (c.2800G>A and c.2978C>G). The genotype showed no effect on the studied traits. The genotype was proven to have significant effects (p<0.05) on ADG2 and MW. The presence of the variant was associated (p<0.01) with decreased ADG2 and MW.
The finding of an association between R gene variation and growth rate after weaning in Barki lambs warrants efforts to improve this trait.
在动物育种中，标记辅助选择比传统选择具有许多优势。候选基因法已被应用于识别与家畜经济重要性状相关的遗传标记。本研究旨在调查激素敏感脂肪酶（）和瘦素受体（）基因的变异及其与巴尔基羔羊生长性状的关联。
获取了247只巴尔基羔羊的出生体重（BW）、断奶前平均日增重（ADG1）、断奶体重（WW）、断奶后平均日增重（ADG2）和出栏体重（MW）记录。采用聚合酶链反应-单链构象多态性分析来检测基因第9外显子和基因第19外显子的变异。使用一般线性模型来检验绵羊基因和基因的变异与生长性状之间的关联。
基因的SSCP条带模式显示出三种变体（、和），其中包含两个核苷酸序列差异（c.1865C>T和c.2038T>C）。基因观察到两种SSCP条带模式（和），其中包含两个核苷酸序列差异（c.2800G>A和c.2978C>G）。基因型对所研究的性状没有影响。基因型被证明对ADG2和MW有显著影响（p<0.05）。变体的存在与ADG2和MW降低相关（p<0.01）。
巴尔基羔羊基因变异与断奶后生长速率之间存在关联这一发现，值得努力改善这一性状。
