Abstract: 【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.

Key words: chicken, mir-1644, seed, a single nucleotide polymorphism