中文摘要：

【目的】观察“seed”区T〉C多态对鸡mir-1644基因“茎环”结构和靶基因选择的影响，分析其在不同鸡群的遗传分布，为揭示其对mir-1644表达调控的影响及表型效应奠定基础。【方法】利用mfold和miRanda软件进行mir-1644二级结构模拟和靶基因预测，采用引入酶切位点RFLP技术对6个鸡群的179个个体进行基因型检测。【结果J①T→C突变可导致pre—mir-1644空间构型和自由能改变，稳定性降低；②预测到21个mir-1644-T和mir-1644-C基因差异调控的靶基因。③在汶上芦花鸡群体内以C等位基因为优势基因，与其它鸡间的基因型分布存在显著差异（P〈0．01）。【结论】“seed”区T〉C突变可能干扰或破坏mir-1644基因的表达调控，且CC基因型可能与汶上芦花鸡某些表型变异有关。

英文摘要：

[ Objective ] This experiment was conducted to study the effect of T 〉 C polymorphisms located in the seed regions of mir-1644 on its stem-loop secondary structure and target selection, and the differences of distribution of this polymorphisms were also detected in different chicken breeds. [Method] The secondary structures of different alleles of mir-1644 and their target genes were predicted using mfold and miranda software respectively. CRS-RFLP technique was used to detected chicken mir-1644 genotype in 6 populations containing 179 individuals. [Result] The results showed that （1） The T→C mutation results in pre-mir-1644 secondary structure change and the free energy of pre-mir-1644-C is higher than that of pre-mir-1644-T; （2） There were 21 target gene differentially regulated by mir-1644-C and mir-1644-T were predicted; （3） Allele C was the dominant allele in Wenshanluhua chicken population, while allele T was the dominant allele in Jiningbairi, Langya, Wugu and populations. The allele and genotype distribution in Wenshangluhua chicken was significantly different with that in other chicken populations （P〈0.01）. [Conclusion] These results indicated that T→C mutation may destroy and alter expression and regulation of mir-1644, and CC genotype may be related to some phenotypic variation of Wenshangluhua Chicken.