中国农业科学 ›› 2024, Vol. 57 ›› Issue (2): 390-402.doi: 10.3864/j.issn.0578-1752.2024.02.013

• 畜牧·兽医 • 上一篇    下一篇

PLZF的克隆及其对犏牛未分化精原细胞的增殖作用

张鹏(), 王明秀, 敬科民, 李雨谦, 田园, 钟金城(), 蔡欣()   

  1. 西南民族大学青藏高原动物遗传资源保护与利用四川省、教育部重点实验室,成都 610041
  • 收稿日期:2023-05-11 接受日期:2023-10-07 出版日期:2024-01-16 发布日期:2024-01-19
  • 通信作者:
    蔡欣,E-mail:
    钟金城,E-mail:
  • 联系方式: 张鹏,E-mail:zhangpeng0536@126.com。
  • 基金资助:
    西南民族大学“双一流”项目(XM2023019); 四川省科学技术厅应用基础科技项目(2021YJ0268)

Cloning of PLZF Gene and Its Effects on the Proliferation of Undifferentiated Spermatogonia in Cattleyak

ZHANG Peng(), WANG MingXiu, JING KeMin, LI YuQian, TIAN Yuan, ZHONG JinCheng(), CAI Xin()   

  1. Key Laboratory of Qinghai-Tibetan Plateau Animal Genetic Resource Reservation and Utilization, Ministry of Education / Sichuan Province, Southwest Minzu University, Chengdu 610041
  • Received:2023-05-11 Accepted:2023-10-07 Published:2024-01-16 Online:2024-01-19

摘要:

【目的】 犏牛作为牦牛与黄牛的种间杂交产物,具有优良的生产性能,但其杂种优势的进一步应用却受限于犏牛雄性不育。通过克隆犏牛PLZF,明确其在犏牛和牦牛睾丸组织和未分化精原细胞中的差异表达,并进一步揭示过表达该基因对犏牛未分化精原细胞活性的影响。为阐明犏牛生精停滞的作用机制提供理论基础。【方法】 以24月龄公麦洼牦牛和F1代公犏牛为实验动物,通过RT-PCR法克隆得到了犏牛PLZF的CDS序列,并进行了生物信息学分析;通过RT-qPCR法分析PLZF在犏牛和牦牛睾丸组织中的差异表达;采用同源重组的方法构建了PLZF的表达载体,并利用RT-qPCR检测了PLZF过表达效率及其下游靶基因的表达;通过PDT、CCK-8、EdU和免疫荧光检测了过表达PLZF对犏牛未分化精原细胞增殖活性的影响。【结果】 克隆获得了犏牛PLZF的CDS区,并通过生物信息学分析发现该基因编码的蛋白序列不包含跨膜结构域和信号肽序列,其三级结构以α螺旋和无规卷曲为主。系统进化树分析表明犏牛PLZF与黄牛PLZF的亲缘关系更近。三级结构预测发现,虽然犏牛、牦牛和黄牛的PLZF蛋白三级结构高度相似,但牦牛PLZF蛋白在531—540位氨基酸处与犏牛和黄牛有较大差异。RT-qPCR发现,PLZF在犏牛睾丸组织和未分化精原细胞中的表达均显著低于牦牛(P<0.05),而在犏牛未分化精原细胞中过表达PLZF后,该基因的表达上调了13.8倍(P<0.01),且能显著增加犏牛未分化精原细胞的增殖活性(P<0.05),表明PLZF表达下调影响了犏牛未分化精原细胞增殖活性。此外,过表达PLZF后,犏牛未分化精原细胞中与增殖相关的基因(Etv5Bcl6bPcnac-fos)全部显著上调(P<0.05),与分化相关的基因(Stra8KitDmrt1Sohlh2)全部显著下调(P<0.05),表明PLZF通过上调增殖相关基因、下调分化相关基因的表达促进犏牛未分化精原细胞增殖。【结论】 PLZF在犏牛未分化精原细胞中表达异常降低了犏牛未分化精原细胞增殖活性,导致其数量减少,影响了犏牛的精子发生。本试验为进一步阐明犏牛生精停滞的作用机制提供了理论基础,并为解决犏牛雄性不育问题提供了新的思路。

关键词: 犏牛, PLZF, 未分化精原细胞, 增殖

Abstract:

【Objective】 As the product of interspecific hybridization between yak and cattle, cattleyak has excellent production performance, but the further application of its heterosis is limited by the male sterility of cattleyak. The aim of the study was to clone the PLZF of cattleyak, and to identify its differential expression in the testicular tissue and undifferentiated spermatogonia of cattleyak and yak, and to further reveal the effect of expressing this gene on the activity of undifferentiated spermatogonia of cattleyak. This study could provide a theoretical basis for clarifying the mechanism of spermatogenesis stagnation in cattleyaks. 【Method】 In this study, 24-month-old male Maiwa yak and F1 generation male cattleyak were used as experimental animals, and the CDS sequences of PLZF in cattleyak were cloned by RT-PCR and analyzed by bioinformatics. The differential expression of PZLF in the testis tissues of cattleyak and yak was analyzed by RT-qPCR. The expression vector of PLZF was constructed by homologous recombination, and the overexpression efficiency and the expression of downstream target genes were detected by RT-qPCR. The effect of overexpression of PLZF on the undifferentiated spermatogonia of cattleyak was detected by PDT, CCK-8, EdU, and immunofluorescence. 【Result】 The CDS region of the PLZF was cloned, and it was found by bioinformatics analysis that the protein sequence encoded by the gene did not contain transmembrane domain and signal peptide sequence, and its tertiary structure was mainly α helix and random curl. Phylogenetic tree analysis showed that the PLZF of cattleyak was more closely related to the PLZF of cattle. The prediction of tertiary structure showed that although the tertiary structure of PLZF protein of cattleyak, yak and cattle was highly similar, the PLZF protein of yak was quite different from that of cattleyak and cattle at amino acids 531-540. RT-qPCR found that the expression levels of PLZF gene in the testis tissue and undifferentiated spermatogonia of cattleyak were significantly lower than that in yak (P<0.05). After overexpression of PLZF, the expression of PLZF in the undifferentiated spermatogonia of the cattleyak was up-regulated by 13.8 times (P<0.01), and the proliferation activity of the undifferentiated spermatogonia of the cattleyak was significantly increased (P<0.05), which showed that the down-regulation of PLZF expression affected the proliferation activity of undifferentiated spermatogonia of cattleyak. In addition, after overexpression of PLZF, the proliferation activity of undifferentiated spermatogonia was significantly increased All proliferation-related genes (Etv5, Bcl6b, Pcna and c-fos) were significantly up-regulated (P<0.05), and all differentiation-related genes (Stra8, Kit, Dmrt1 and Sohlh2) were significantly down-regulated (P<0.05), indicating that PLZF could promote the proliferation of undifferentiated spermatogonia by up-regulating the expression of proliferation-related genes and down-regulating the expression of differentiation-related genes.【Conclusion】 The abnormal expression of PLZF in cattleyak undifferentiated spermatogonia reduced the proliferative activity of cattleyak undifferentiated spermatogonia, resulting in its decrease in number and affecting the spermatogenesis of cattleyak. This study provided a theoretical basis for further elucidation of the mechanism of spermatogenesis and stagnation in cattleyak, and a new idea for solving the problem of male sterility in cattleyak.

Key words: cattleyak, PLZF, undifferentiated spermatogonia, proliferation