Adaptive evolutionary expansion of the ribonuclease 6 in Rodentia
Adaptive evolutionary expansion of the ribonuclease 6 in Rodentia
复制标题
啮齿动物中核糖核酸酶 6 的适应性进化扩展
DOI：
10.1111/1749-4877.12382
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发表时间：
2019-05-01
影响因子：
3.3
通讯作者：
Wang, Xiaoping
中科院分区：
文献类型：
--
作者：
Lang, Datian;Lim, Burton K.;Wang, Xiaoping
核糖核酸酶6（RNase 6或RNase K6）是属于超家族的蛋白质，被认为是已知用于广泛生理功能的唯一脊椎动物特异性酶，包括消化、细胞毒性、血管生成、雄性生殖和宿主防御。本研究从27种啮齿动物中鉴定出51个功能基因和11个假基因。有趣的是，在啮齿类的3个主要谱系中，在Ctenohystrica的所有物种中鉴定出多个RNase6，而在所检查的其他啮齿类物种中仅观察到单个RNase6，除了在小鼠相关分支中的2个物种。“出生（基因复制）和死亡（基因失活）”和基因排序的进化情景已在栉孔扇贝中得到证实。此外，爆发的正选择，多样化的等电点和正净电荷已被确定在栉孔扇贝，特别是在两个关键的网站，参与抗菌功能。B、C群栉孔扇贝中Trp 30位点发生正选择，Ile 45位点发生变化。我们的研究结果显示了啮齿动物RNase6复杂而有趣的进化模式，并表明可能发生了功能修饰，这为啮齿动物RNase6的未来功能测定奠定了重要的理论基础。
Ribonuclease 6 (RNase6 or RNase K6) is a protein that belongs to a superfamily thought to be the sole verte-brate-specific enzyme known for a wide range of physiological functions, including digestion, cytotoxicity, angiogenesis, male reproduction and host defense. In our study, 51 functional genes and 11 pseudogenes were identified from 27 Rodentia species. Intriguingly, in the 3 main lineages of rodents there were multiple RNase6s identified in all species of Ctenohystrica, whereas only a single RNase6 was observed in other Rodentia species examined except for 2 species in the mouse-related clade. The evolutionary scenario of "birth (gene duplication) and death (gene deactivation)" and gene sorting have been demonstrated in Ctenohystrica. In addition, bursts of positive selection, diversification of isoelectric point and positive net charge have been identified in Ctenohystrica, especially at two key sites that are involved in antimicrobial function. Site Trp30 has undergone positive selection and Ile45 has changed into other residues in Group B and Group C of the Ctenohystrica. Our results demonstrated a complex and intriguing evolutionary pattern of rodent RNase6, and indicated that functional modification may have occurred, which establishes an important theoretical foundation for future functional assays in rodent RNase6.