Abstract: This experiment was conducted to study molecular evolution, cloning and sequence analysis of Qinghai Semifine-wool sheep interleukin-8 (IL-8) gene. A pair of specific primers was designed based on GenBank. The IL-8 gene was amplified by RT-PCR and cloned into pMD18-T vector. The positive recombinant plasmids which was transformed to E.coli DH5α was identified by PCR and restriction enzyme digestion and sequenced analysis. The results showed that sheep peripheral blood lymphocytes was amplified bands consistent with the expected size (370 bp), the homology analysis showed that IL-8 gene was more conservative, which homology was 96.1% to 99.0%.

Key words: IL-8 gene; cloning; sequence analysis; Semifine-wool sheep