高原与平原饲养条件下麦洼牦牛RNA编辑位点的鉴定与分析

Identification and analysis of RNA editing sites of Maiwa yak under plateau and plain feeding conditions

为了揭示牦牛在高原与平原饲养条件下的RNA序列分子编辑位点、类型及功能,进而为牦牛的臀肌组织生长、发育、分化及与环境相互作用等研究提供更多的信息,试验将10头麦洼牦牛随机均分成平原组和高原组,每组5头,分别于2018年12月14日—2019年5月12日(冷季)在四川省广汉市(海拔为600 m,平原组)和四川省阿坝藏族羌族自治州红原县(海拔为3 500 m,高原组)进行舍饲栓系和放牧饲养,饲养期间每30 d称量体重1次;试验结束后,屠宰试验牛,取其臀肌组织,通过Illumina HiSeq^(TM)4000测序平台进行高通量测序,利用SPRINT、 JACUSA、RNA-DNA差异位点(RDDs)和RNA-RNA差异位点(RRDs)探测RNA编辑位点(REs),并对REs进行分类、对其所在基因进行GO功能注释及变异风险评估。结果表明:平原组体重在试验第60天时显著高于高原组(P<0.05),90~150天时极显著高于高原组(P<0.01)。总计发现4 351个REs,以A>G、G>A、C>T和T>C编辑类型为主;平原组REs主要富集在大分子代谢过程,高原组REs主要富集在核仁中;仅在平原组中含有2个高风险编辑位点,使ADCY2基因提前终止蛋白质翻译,进而可能影响磷酸化及糖原合成和分解。说明牦牛RNA编辑模式受环境调控,能够影响牦牛臀肌组织的生长发育。

In order to reveal the RNA sequence molecular editing sites, types and functions of yaks under the conditions of plateau and plain feeding, and to provide more information sources for the research on the growth, development and differentiation of yak gluteal muscle tissue and the interaction with the environment, etc., in the experiment, 10 Maiwa yaks were randomly divided into the plain group and the plateau group with 5 heads in each group;tethering and grazing were carried out respectively in Guanghan City, Sichuan Province(600 m above sea level, plain group) and in Hongyuan County, Aba Tibetan and Qiang Autonomous Prefecture, Sichuan Province(3 500 m above sea level, plateau group), from December 14, 2018 to May 12, 2019(cold season). The yak body weight was weighed once every 30 days during the feeding period. After the experiment, the test cows were slaughtered, and the gluteal muscle tissue was taken for high-throughput sequencing using the Illumina HiSeq^(TM)4000 sequencing platform. SPRINT, JACUSA, RNA-DNA differences(RDDs) and RNA-RNA differences(RRDs) were used to detect RNA editing sites. The REs were classified, and their genes were functionally annotated and variant risk was assessed. The results showed that the body weight of the plain group was significantly higher than that of the plateau group on the 60 th day of the experiment(P<0.05), and was significantly higher than that of the plateau group from 90 th to the 150 th days(P<0.01). A total of 4 351 REs were found dominated by A>G, G>A, C>T and T>C editing types. The REs of the plain group were mainly enriched in macromolecular metabolic processes, and the REs of the plateau group were mainly enriched in the nucleolus. Containing 2 high-risk editing sites only in the plain group caused the ADCY2 gene to prematurely terminate protein translation, which in turn may affect phosphorylation and glycogen synthesis and breakdown. The results suggested that the yak RNA editing mode was regulated by the environment and could affect the growth and development of the yak gluteal muscle tissue.