不同发育阶段大通牦牛骨骼肌肌纤维类型及MyHC基因表达  

Muscle fiber types and MyHC gene expression in skeletal muscle of Datong yak at different developmental stages

作　　者：秦鸿楠 周娟 李琳 申什菊 张勤文[1] QIN Hongnan;ZHOU Juan;LI Lin;SHEN Shenju;ZHANG Qinwen(Agricultural and Animal College,Qinghai University,Xining 810016,China;Department of Animal Husbandry,Agricultural Development Com mission of Haidong City,Haidong,Qinghai 814000,China)

机构地区：[1]青海大学农牧学院,青海西宁810016 [2]青海省海东市农发委畜牧科,青海海东814000

出　　处：《中国兽医学报》2023年第1期152-157,共6页Chinese Journal of Veterinary Science

基　　金：青海省科技厅资助项目(2017-ZJ-718)。

摘　　要：为了阐明不同发育阶段大通牦牛骨骼肌纤维类型变化特点及其低氧适应机制,本试验从青海省大通县(海拔3200 m)选取健康的1,30,180日龄和成年的大通牦牛作为研究对象,选择湖北省襄阳市(海拔约100 m)相同发育阶段的平原黄牛作为对照,采用免疫组织化学染色的方法观测骨骼肌中快肌和慢肌的含量及比例的变化;采用实时荧光定量PCR检测不同海拔牦牛骨骼肌肌球蛋白重链(myosin heavy chain,MYHC)基因各亚型mRNA表达的变化。结果表明:随年龄增长,大通牦牛骨骼肌快肌数量逐渐增多,慢肌数量比逐渐减少(P<0.05);在同一发育阶段,大通牦牛骨骼肌快慢肌数量比均高于平原黄牛,且差异显著(P<0.05);随着年龄的增长,大通牦牛快慢肌面积比呈现逐渐减少的趋势;在相同发育阶段时,除30日龄外,大通牦牛快肌面积比在其余3个年龄段均低于平原黄牛,而慢肌面积比则高于平原黄牛;大通牦牛骨骼肌中MyHCⅠmRNA含量逐渐升高,MyHCⅡa mRNA含量先升高后降低,MyHCⅡx和MyHCⅡb mRNA含量逐渐降低,且呈现随年龄增长快肌向慢肌转化的特点。以上结果说明了大通牦牛骨骼肌MyHCⅠ、Ⅱa、Ⅱx、Ⅱb基因在不同年龄段的表达情况,同时证明MyHC 4种亚型的mRNA表达量可能与低氧环境有一定联系,大通牦牛为适应高原低氧环境,其骨骼肌肌纤维类型呈现快肌向慢肌转化的发育性模式,为深入研究大通牦牛的低氧适应机制提供了基础数据。This study aims to clarify the characteristics of changes in skeletal muscle fiber types in Datong yak in different developmental periods and their hypoxia adaptation mechanism.The experiment selected healthy 1,30,180-day-old and adult Datong yak from Datong County,Qinghai Province(altitude 3200 m)as the research object,and selected the plain of Xiangyang City,Hubei Province(about 100 m above sea level)at the same developmental stage.Yellow cattle were used as control,and immunohistochemical staining was used to observe the changes in the content and ratio of fast muscle and slow muscle in skeletal muscle;real-time fluorescence quantitative PCR was used to detect the changes of mRNA expression of each subtype of the myosin heavy chain(MYHC)gene in skeletal muscle of yak at different altitudes.The results showed that:with the increase of age,the number of fast muscle mass in skeletal muscle of Datong yak gradually increased,while the ratio of slow muscle mass gradually decreased(P<0.05);the area ratio of fast and slow muscle of Datong yak showed a decreasing trend;at the same development stage,except for 30 days old,the area ratio of fast muscle of Datong yak was the same in the other three age groups.Compared with plain cattle,the area ratio of slow muscle was higher than that of plain cattle.The content of MyHCⅠmRNA in the skeletal muscle of Datong yak gradually increased,while the content of MyHCⅡa,MyHCⅡx and MyHCⅡb mRNA gradually decreased,and showed the characteristics of fast muscle to slow muscle transformation with age.The above results illustrate the expression of MyHCⅠ,Ⅱa,Ⅱx andⅡb genes in the skeletal muscle of Datong yak at different ages,and also demonstrate that the mRNA expression of the four MyHC isoforms may be related to the hypoxic environment,and the skeletal muscle fiber types of Datong yak show a developmental pattern of fast to slow muscle transformation in order to adapt to the highland hypoxic environment,which provides basic data for the in-depth study of the hypoxic adapt

关 键 词：大通牦牛 骨骼肌 肌纤维类型 MYHC 低氧适应机制 

分 类 号：S811[农业科学—畜牧学]