Abstract：
We previously identified quantitative trait loci (QTL) for body weight and average daily gain in a common region between ADL0198 (chr 1: 171.7 Mb) and ABR0287 (chr 1: 173.4 Mb) on chicken chromosome 1 in an F2 resource population produced by crossing low- and high-growth lines of the Hinai-dori breed. Motilin receptor (MLNR) is a candidate gene affecting growth traits in the region. In this study, we genotyped polymorphisms of the MLNR gene and investigated its association with growth traits in a Hinai-dori F2 intercross population. All the exons of the MLNR gene in the parental population were subjected to PCR amplification, nucleotide sequenced and haplotypes identified. To distinguish resultant diplotype individuals in the F2 population, a mismatch amplification mutation assay was performed. Three haplotypes (Haplotypes 1-3) were accordingly identified. Six genotypes produced by the combination of three haplotypes (Haplotype 1, 2, and 3) were examined in order to identify associations between MLNR haplotypes and growth traits. The data showed that Haplotype 1 was superior to Haplotype 2 and 3 in body weight at 10 and 14 weeks of age, average daily gain between 4 and 10 weeks, 10 and 14 weeks, and 0 and 14 weeks of age in female in F2 females. It was concluded that MLNR is a useful marker of growth traits and could be used to develop strategies for improving growth traits in the Hinai-dori breed.
摘要：
我们先前在F2资源种群中的鸡1号染色体上的ADL0198（chr1：171.7Mb）和ABR0287（chr1：173.4Mb）之间的共同区域中确定了体重和平均日增重的定量性状基因座（QTL）通过杂交Hinai-dori品种的低和高生长系。胃动素受体(MLNR)是影响该区域生长性状的候选基因。在这项研究中,我们对MLNR基因的多态性进行了基因分型，并研究了其与Hinai-doriF2杂交种群中生长性状的关联。对亲本群体中MLNR基因的所有外显子进行PCR扩增，核苷酸测序和单倍型鉴定。为了区分F2群体中产生的复型个体，进行了错配扩增突变测定.相应地鉴定了三种单倍型(单倍型1-3)。检查了由三种单倍型（单倍型1、2和3）组合产生的六种基因型，以鉴定MLNR单倍型与生长性状之间的关联。数据显示，单倍型1在10和14周龄时的体重优于单倍型2和3，4到10周之间的平均每日增益，10和14周，F2雌性中0和14周龄。结论MLNR是生长性状的有用标记，可用于制定改善Hinai-dori品种生长性状的策略。
