College of Wildlife Resources, Northeast Forestry University, Harbin, 150040, China.
School of Earth Sciences, East China University of Technology, Nanchang, 330013, China.
Genes Genomics. 2019 Sep;41(9):1007-1013. doi: 10.1007/s13258-019-00829-3. Epub 2019 May 27.
Reindeer is the only deer species that both male and female produce antlers, which provides a particularly interesting case in studying the differences between antlers of the two sexes. Alpha 3(VI) Collagen Gene (COL6A3), forms a microfibrillar network associated with the structural integrity and biomechanical properties, has been found to be one of the differentially expressed genes in antler mesenchyme of female and male reindeer.
The promoter sequence of reindeer COL6A3 gene was obtained using the cloning technology and analyzed by the bioinformatics methods. Bisulfite sequencing PCR (BSP) was used to detect the methylation status of the COL6A3 promoter in reindeer antler mesenchyme. Real-time quantitative PCR was used to detect COL6A3 expression in the antler mesenchyme of female and male reindeer.
Sequence analysis revealed that the reindeer COL6A3 partial promoter sequence was 983 bp including the possible promoter region at + 105 bp to + 155 bp. Homology and phylogenetic analysis indicated that the COL6A3 promoter of reindeer had the closest genetic distance with Bos taurus, Capra hircus and Ovis aries. BSP results indicated that the methylation level of COL6A3 promoter in the female reindeer antler mesenchyme was significantly higher than in the male. Correlating with increased methylation status, we also found that COL6A3 mRNA expression in female reindeer antler mesenchyme was significantly lower than in the male.
The higher methylation level of the COL6A3 gene in female reindeer antler mesenchyme coincides with decreased COL6A3 mRNA expression, thereby affecting the transposon silencing mechanism and possibly contributing to apparent differences of antlers in female and male reindeer.
驯鹿是唯一雌雄都长角的鹿种，这为研究雌雄驯鹿角之间的差异提供了一个特别有趣的案例。α 3(VI) 胶原蛋白基因（COL6A3）形成与结构完整性和生物力学特性相关的微纤维网络，已被发现是雌雄驯鹿鹿角间差异表达基因之一。
采用克隆技术获得驯鹿 COL6A3 基因启动子序列，利用生物信息学方法进行分析。亚硫酸氢盐测序 PCR（BSP）用于检测驯鹿鹿角间质中 COL6A3 启动子的甲基化状态。实时定量 PCR 用于检测雌性和雄性驯鹿鹿角间质中 COL6A3 的表达。
序列分析表明，驯鹿 COL6A3 部分启动子序列为 983bp，包括可能在 +105bp 到 +155bp 的启动子区域。同源性和系统发育分析表明，驯鹿 COL6A3 启动子与 Bos taurus、Capra hircus 和 Ovis aries 的遗传距离最近。BSP 结果表明，雌性驯鹿鹿角间质中 COL6A3 启动子的甲基化水平明显高于雄性。与甲基化状态的增加相关，我们还发现雌性驯鹿鹿角间质中 COL6A3 mRNA 的表达明显低于雄性。
雌性驯鹿鹿角间质中 COL6A3 基因的高甲基化水平与 COL6A3 mRNA 表达的降低相吻合，从而影响转座子沉默机制，并可能导致雌雄驯鹿的鹿角存在明显差异。
