Expression of the Testis-Specific Serine/Threonine Kinases Suggests Their Role in Spermiogenesis of Bay Scallop Argopecten irradians

Abstract

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 Argopecten irradians 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 Tssks in four developmental stages of testes and ovaries, we found all five Tssks were primarily expressed in mature testis. In situ hybridization experiment revealed the five Tssks 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 A. irradians. To our knowledge, it represents the first comprehensive analysis of Tssk family in mollusks.

The Biological Characteristics and Differential Expression Patterns of TSSK1B Gene in Yak and Its Infertile Hybrid Offspring

“…In the testis, the spermatogenesis could be divided into three phases: the proliferation stage, where the spermatogonia generates a pool of spermatocytes by mitotic division; the meiosis stage, where haploid spermatids are generated; and the spermiogenesis stage, which allows the spermatids to be differentiated into spermatozoa [30]. In the current study, the expression pattern of TSSK1B in various yak tissues was detected by RT-qPCR, and the results showed that TSSK1B was specifically expressed in yak testis, which was typically observed in mammalian TSSK1B and in agreement with other previous study [13,31]. Furthermore, the mRNA expression abundances of yak TSSK1B transcripts were correlated with the age of the males, in which a positive relationship could be observed between TSSK1-like expression levels and the degree of testis maturation.…”

Growth Traits and Sperm Proteomics Analyses of Myostatin Gene-Edited Chinese Yellow Cattle

“…The testis-specific serine/threonine kinase (TSSK) has been demonstrated to play essential roles in spermatogenesis, such as TSSK1b , TSSK2 , and TSSK4 encode kinases regulating sperm motility and fertility [ 53 ]. The gene TSSK4 has proven to be essential for maintaining the structural integrity of sperm flagellum, and TSSK4 -KO mice exhibit an impaired sperm structure and reduced sperm motility, which affects fertility [ 51 ], and up-regulated TSSK4 can restore fertility of male mice [ 54 ].…”

Using the Culex pipiens sperm proteome to identify elements essential for mosquito reproduction

“…The testis specific serine/threonine kinases (TSSKs) were first identified as novel kinases expressed specifically in mouse testis [ 17 , 18 ] that played a role in spermiogenesis. They have since been identified in many animal taxa, both invertebrate (scallop [ 19 ]) and abalone [ 20 ]) and vertebrate (mouse [ 18 , 19 ], bull [ 21 ], human [ 22 ]). However, subsequent work has shown that several TSSKs are present in mature mouse and human sperm [ 22 ], suggesting that they may play a role in the physiology of mature sperm, in addition to their roles in sperm morphogenesis.…”