Qin N, Liu Q, Zhang Y Y, Fan X C, Xu X X, Lv Z C, Wei M L, Jing Y, Mu F, Xu R F
Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Jilin Agricultural University, Changchun 130118, Jilin, China.
Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan 130118, Hubei, China.
Poult Sci. 2015 Jan;94(1):88-95. doi: 10.3382/ps/peu023.
Transcription factor forkhead box L2 (FOXL2) and growth differentiation factor-9 (GDF9) genes have critical roles in the regulation of hen ovarian development. In the present study, these genes were explored as possible molecular markers associated with BW, hen-housed egg production, and egg weight in Chinese Dagu hens. Samples were analyzed using the PCR-single strand conformation polymorphism (PCR-SSCP) technique followed by sequencing analysis, and two novel single nucleotide polymorphisms (SNPs) were identified within these candidate genes. Among them, an A/G transition at base position 238 in the coding region of the FOXL2 gene and a G/T transversion at base position 1609 in exon 2 of the GDF9 gene were found to be polymorphic and named SNPs A238G and G1609T, respectively. The SNP A238G (FOXL2) leads to a nonsynonymous substitution (isoleucine77-to-valine), and when the 360 Dagu hen samples were divided into genotypes AA and AB, allele A was found to be present at a higher frequency. Furthermore, the AA genotype correlated with significantly higher hen-housed egg production at 30, 43, 57, and 66 wk of age and with a higher egg weight at 43 wk (P<0.05). For the SNP G1609T (GDF9), the hens were typed into TT and TC genotypes, with the T allele shown to be dominant. The TC genotype was also markedly correlated with higher hen-housed egg production and a higher egg weight (P<0.05). Moreover, four haplotypes were reconstructed based on these two SNPs, with the AATC haplotype found to be correlated with the highest hen-housed egg production at 30 to 66 wk of age and with higher egg weights at 43 wk (P<0.05). Collectively, the two SNPs identified in this study might be used as possible genetic molecular markers to aid in the improvement of egg production traits in chicken breeding.
转录因子叉头框L2（FOXL2）和生长分化因子9（GDF9）基因在母鸡卵巢发育调控中起关键作用。在本研究中，对这些基因作为与中国大沽鸡体重、入舍母鸡产蛋量和蛋重相关的潜在分子标记进行了探索。采用聚合酶链反应-单链构象多态性（PCR-SSCP）技术对样本进行分析，随后进行测序分析，在这些候选基因中鉴定出两个新的单核苷酸多态性（SNP）。其中，FOXL2基因编码区第238位碱基处的A/G转换以及GDF9基因第2外显子第1609位碱基处的G/T颠换被发现具有多态性，分别命名为SNP A238G和G1609T。SNP A238G（FOXL2）导致非同义替换（异亮氨酸77变为缬氨酸），当将360只大沽鸡样本分为AA和AB基因型时，发现等位基因A的频率较高。此外，AA基因型与30、43、57和66周龄时显著更高的入舍母鸡产蛋量以及43周龄时更高的蛋重相关（P<0.05）。对于SNP G1609T（GDF9），母鸡被分为TT和TC基因型，T等位基因显示为显性。TC基因型也与更高的入舍母鸡产蛋量和更高的蛋重显著相关（P<0.05）。此外，基于这两个SNP重建了四种单倍型，发现AATC单倍型与30至66周龄时最高的入舍母鸡产蛋量以及43周龄时更高的蛋重相关（P<0.05）。总体而言，本研究中鉴定出的这两个SNP可能用作潜在的遗传分子标记，以帮助改善鸡育种中的产蛋性状。
