Xue Xinru, Zhang Lingling, Li Yajuan, Wei Huilan, Wu Shaoxuan, Liu Tian, Liu Liangjie, Xing Qiang, Wang Shi, Bao Zhenmin
MOE Key Laboratory of Marine Genetics and Breeding, Ocean University of China, Qingdao, China.
Laboratory for Marine Fisheries Science and Food Production Processes, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao, China.
Front Physiol. 2021 Mar 30;12:657559. doi: 10.3389/fphys.2021.657559. eCollection 2021.
Members of the testis-specific serine/threonine kinases (Tssk) family play critical roles in spermatogenesis in vertebrates. But in mollusks, research on Tssk family is still lagging. In this study, we systematically identified Tssk family based on the genomic and transcriptomic data from a commercially important scallop and detected the spatiotemporal expression in adult gonads. Five members were identified, with the gene length varying from 1,068 to 10,729 bp and the protein length ranging from 294 to 731 aa. All the Tssks possess a serine/threonine protein kinase catalytic (S_TKc) domain. Phylogenetic analysis revealed existence of four homologs of vertebrate Tssk1/2, Tssk3, Tssk4, Tssk5, and absence of Tssk6 in the scallop. The remaining gene (Tssk7) formed an independent clade with Tssks of other mollusks and arthropods, indicating that it may be a new member of Tssk family unique to protostomes. By investigating the expression of in four developmental stages of testes and ovaries, we found all five were primarily expressed in mature testis. hybridization experiment revealed the five were localized in the spermatids and spermatozoa. The testis-predominant expression of Tssk family suggests Tssks may play pivotal roles in spermiogenesis in the scallop. Our study provides basic information on the characteristics and expression profiles of Tssk family of . To our knowledge, it represents the first comprehensive analysis of Tssk family in mollusks.
睾丸特异性丝氨酸/苏氨酸激酶（Tssk）家族成员在脊椎动物精子发生过程中发挥着关键作用。但在软体动物中，对Tssk家族的研究仍很滞后。在本研究中，我们基于一种具有重要商业价值的扇贝的基因组和转录组数据，系统地鉴定了Tssk家族，并检测了其在成年性腺中的时空表达。我们鉴定出了五个成员，基因长度在1068至10729碱基对之间，蛋白质长度在294至731个氨基酸之间。所有Tssk都拥有一个丝氨酸/苏氨酸蛋白激酶催化（S_TKc）结构域。系统发育分析显示，扇贝中存在脊椎动物Tssk1/2、Tssk3、Tssk4、Tssk5的四个同源物，而不存在Tssk6。其余基因（Tssk7）与其他软体动物和节肢动物的Tssk形成了一个独立的进化枝，这表明它可能是原口动物特有的Tssk家族新成员。通过研究其在睾丸和卵巢四个发育阶段的表达，我们发现所有五个成员主要在成熟睾丸中表达。原位杂交实验表明，这五个成员定位于精子细胞和精子中。Tssk家族在睾丸中的优势表达表明，Tssk可能在扇贝精子形成过程中发挥关键作用。我们的研究提供了关于扇贝Tssk家族特征和表达谱的基础信息。据我们所知，这是对软体动物Tssk家族的首次全面分析。
