Abstract

Endoplasmic reticulum stress (ERS) plays an important role in regulating the reproductive process of female mammals, mainly involved in follicular atresia and corpus luteum regression. DNA damage induced transcript 3 (DDIT3) is a marker gene of ERS. The objectives of the present study were to clone and analyze the sequence and tissue expression characteristics of DDIT3 gene in female yaks. By reverse transcriptase-polymerase chain reaction (RT-PCR) strategy, we obtained full-length 507-bp DDIT3-cDNA, encoding for 168-aa protein. Yak DDIT3 exhibited highest and least identity with that of bison and horse, respectively. Real-time PCR analyses revealed that the expression level of DDIT3 gene in ovary was higher than that in heart, liver, kidney, spleen, lung, uterus and oviduct (p < 0.05). DDIT3 expression level in ovary and uterus during pregnancy was higher than that in follicular phase, luteal phase and fetus stage. DDIT3 was highly expressed in metaphase II oocytes and granulosa cells than that in germinal vesicle and metaphase I oocytes (p < 0.05), respectively. This is the first molecular characterization and expression patterns of DDIT3 gene in female yaks. These results indicated that the DDIT3 gene possibly plays an important role in regulating ovary function and pregnancy maintenance in yaks.

摘要

内质网应激(endoplasmic reticulum stress, ERS)在雌性哺乳动物的生殖过程中起重要调节作用,主要参与卵泡闭锁和黄体退化。DNA损伤诱导转录物3（DDIT3）是ERS的标志基因。本研究的目的是克隆和分析雌性牦牛DDIT3基因的序列和组织表达特征。通过逆转录聚合酶链反应 (RT-PCR) 策略，我们获得了全长 507-bp DDIT3-cDNA，编码 168-aa 蛋白。牦牛 DDIT3 分别表现出与野牛和马的最高和最低同一性。Real-time PCR 分析显示 DDIT3 基因在卵巢中的表达水平高于心脏、肝脏、肾脏、脾脏、肺、子宫和输卵管（p < 0.05)。DDIT3在孕期卵巢和子宫中的表达水平高于卵泡期、黄体期和胎儿期。DDIT3 在中期 II 卵母细胞和颗粒细胞中的表达分别高于生发泡和中期 I 卵母细胞 ( p  < 0.05)。这是DDIT3基因在雌性牦牛中的首次分子鉴定和表达模式。这些结果表明DDIT3基因可能在牦牛卵巢功能调控和妊娠维持中发挥重要作用。