线粒体基因组具有种内高度保守性。它的12S rRNA基因同时具有抗腐蚀、耐高温的特点, 而被用于饲料、鲜肉及肉制品的来源追踪和物种成分鉴别等研究。利用牦牛、普通牛、水牛作为研究材料, 在牛线粒体12S rRNA基因通用引物扩增片段区域发现3种特异的酶切位点, 可用于混合鲜牛肉及制品的牛种来源的鉴别。结果显示: 牦牛12S rRNA扩增片段被酶切为203 bp和250 bp, 普通牛为134 bp和318 bp, 水牛为86 bp和367 bp, 通过测序验证了特异性位点和酶切的正确性; 对样品经过不同温度(100℃、120℃、140℃、160℃和180℃)处理均能扩增到目的条带, 但条带从120℃开始变淡。该方法在鲜牛肉及制品的牛种来源鉴别上具有简单、快速、廉价等优点。

Mitochondrial DNA sequence is highly conserved within species. Gene 12S rRNA is able to endure degeneration and high temperature, which allows identification of feedstuff, fresh meat, processed meat, and traceability. In the present study, three unique restriction sites were detected in the fragments of mitochondrial 12S rRNA gene regions amplified with universal primer, which were able to distinguish Bos grunniens, Bos. taurus, and Bubalus in fresh meat and processed meat mixture. The fragment of yak was digested to 134 bp and 318 bp, scalper 134 bp and 318 bp, and buffalo 86 bp and 367 bp. The specific locus and digestion were verified by sequencing analysis. There was no difference between PCR amplification products from various treatments at different temperatures (i.e., 100℃, 120℃, 140℃, 160℃, and 180℃). However, the sig-nal was weak at 120℃ and above. This method is simple, fast and cheap in identification of fresh meat and processed meat.