Characterization of a novel, testis-specific equine serine/threonine kinase

Loss-of-function in testis-specific serine/threonine protein kinase triggers male infertility in an invasive moth

Genetic biocontrol technologies present promising and eco-friendly strategies for the management of pest and insect-transmitted diseases. Although considerable advancements achieve in gene drive applications targeting mosquitoes, endeavors to combat agricultural pests have been somewhat restricted. Here, we identify that the testis-specific serine/threonine kinases (TSSKs) family is uniquely expressed in the testes of Cydia pomonella, a prominent global invasive species. We further generated male moths with disrupted the expression of TSSKs and those with TSSKs disrupted using RNA interference and CRISPR/Cas9 genetic editing techniques, resulting in significant disruptions in spermiogenesis, decreased sperm motility, and hindered development of eggs. Further explorations into the underlying post-transcriptional regulatory mechanisms reveales the involvement of lnc117962 as a competing endogenous RNA (ceRNA) for miR-3960, thereby regulating TSSKs. Notably, orchard trials demonstrates that the release of male strains can effectively suppress population growth. Our findings indicate that targeting TSSKs could serve as a feasible avenue for managing C. pomonella populations, offering significant insights and potential strategies for controlling invasive pests through genetic sterile insect technique (gSIT) technology.

Comparative multi-tissue analyses identify testis-specific serine/threonine protein kinase (TSSK) genes involved in male fertility in the melon fly Zeugodacus cucurbitae

BACKGROUND

Zeugodacus cucurbitae is an agricultural pest species with robust reproductive capabilities capable of causing extensive damage. The advent of novel male fertility-related pest control strategies has been an area of active entomological research focused on the sterile insect technique (SIT) strategy.

RESULTS

RNA-sequencing analyses were conducted using 16 tissue samples from adult male Z. cucurbitae, leading to the identification of 5338 genes that were differentially expressed between the testes and three other analyzed tissue types. Of these genes, 808 exhibited high levels of testis expression. A quantitative polymerase chain reaction (qPCR) approach was used to validate the expression of ten of these genes selected at random, including ZcTSSK1 and ZcTSSK3, which are testis-specific serine/threonine protein kinase (TSSK) genes. Evaluation via a loss-of-function-based knockdown assay showed that the down-regulation of either of these two genes in males was associated with significantly decreased egg hatching rates. In situ hybridization analyses revealed the expression of both of these transcripts in the transformation zone, and significant decreases in Z. cucurbitae sperm numbers were observed following double-stranded RNA treatment. Together, these results suggested that inhibiting ZcTSSK1 and ZcTSSK3 expression was sufficient to alter male fertility in Z. cucurbitae.

CONCLUSION

These transcriptional sequencing results provide a foundation for further efforts to clarify the regulators of Z. cucurbitae male fertility. These preliminary analyses of the functions of ZcTSSK family genes as regulators of spermatogenesis underscore their importance in the processes integral to male fecundity and their potential as targets for pest control efforts centered on the genetic manipulation of males. © 2023 Society of Chemical Industry.

STK31 upregulation is associated with chromatin remodeling in gastric cancer and induction of tumorigenicity in a xenograft mouse model

Pathological changes in the epigenetic landscape of chromatin are hallmarks of cancer. Our previous study showed that global methylation of promoters may increase or decrease during the transition from gastric mucosa to intestinal metaplasia (IM) to gastric cancer (GC). Here, CpG hypomethylation of the serine/threonine kinase STK31 promoter in IM and GC was detected in a reduced representation bisulfite sequencing database. STK31 hypomethylation, which resulted in its upregulation in 120 cases of primary GC, was confirmed. Using public genome-wide histone modification data, upregulation of STK31 promoter activity was detected in primary GC but not in normal mucosae, suggesting that STK31 may be repressed in gastric mucosa but activated in GC as a consequence of hypomethylation-associated chromatin remodeling. STK31 knockdown suppressed the proliferation, colony formation and migration activities of GC cells in vitro, whereas stable overexpression of STK31 promoted the proliferation, colony formation, and migration activities of GC cells in vitro and tumorigenesis in nude mice. Patients with GC in which STK31 was upregulated exhibited significantly shorter survival times in a combined cohort. Thus, activation of STK31 by chromatin remodeling may be associated with gastric carcinogenesis and also may help predict GC prognosis.

Genetics of Equine Reproductive Diseases

Reproductive disorders are genetically heterogeneous and complex; available genetic tests are limited to chromosome analysis and 1 susceptibility gene. Cytogenetic analysis should be the first test to confirm or rule out chromosomal aberrations. No causative genes/mutations are known. The only available genetic test for stallion subfertility is based on a susceptibility gene FKBP6. The ongoing progress in equine genomics will improve the status of genetic testing. However, because subfertile phenotypes do not facilitate collection of large numbers of samples or pedigrees, and clinical causes of many cases remain unknown, further progress requires constructive cross-talk between geneticists, clinicians, breeders, and owners.

Transcriptome Sequencing Reveals the Traits of Spermatogenesis and Testicular Development in Large Yellow Croaker (Larimichthys crocea)

Larimichthys crocea is an economically important marine fish in China. To date, the molecular mechanisms underlying testicular development and spermatogenesis in L. crocea have not been thoroughly elucidated. In this study, we conducted a comparative transcriptome analysis between testes (TES) and pooled multiple tissues (PMT) (liver, spleen, heart, and kidney) from six male individuals. More than 54 million clean reads were yielded from TES and PMT libraries. After mapping to the draft genome of L. crocea, we acquired 25,787 genes from the transcriptome dataset. Expression analyses identified a total of 3853 differentially expressed genes (DEGs), including 2194 testes-biased genes (highly expressed in the TES) and 1659 somatic-biased genes (highly expressed in the PMT). The dataset was further annotated by blasting with multi-databases. Functional genes and enrichment pathways involved in spermatogenesis and testicular development were analyzed, such as the neuroactive ligand-receptor interaction pathway, gonadotropin-releasing hormone (GnRH) and mitogen-activated protein kinase (MAPK) signaling pathways, cell cycle pathway, and dynein, kinesin, myosin, actin, heat shock protein (hsp), synaptonemal complex protein 2 (sycp2), doublesex- and mab-3-related transcription factor 1 (dmrt1), spermatogenesis-associated genes (spata), DEAD-Box Helicases (ddx), tudor domain-containing protein (tdrd), and piwi genes. The candidate genes identified by this study lay the foundation for further studies into the molecular mechanisms underlying testicular development and spermatogenesis in L. crocea.

Characterization of MAGEG2 with testis-specific expression in mice

Male germ cell development is a well-defined process occurring in numerous seminiferous tubules of the testis. Uncovering testicular novel genes related to intrinsic regulation of spermatogenesis is essential for the understanding of spermatogenesis. In the present study, we investigated mouse Mageg2, which belongs to a group of melanoma-associated antigens (MAGEs). Mageg2 is transcribed in the testis specifically, and its expression level is increased at the pachytene spermatocyte stage, indicating that Mageg2 is expressed predominantly in germ cells. We generated an antibody against mouse MAGEG2 for further characterization at the protein level. Immunoblot analysis suggested that MAGEG2 has specific testicular expression and the expression primarily occurred in pachytene spermatocytes. Proteomic analyses demonstrated that mouse MAGEG2 binded to testicular germ cell-specific serine/threonine-protein kinase 31 (STK31) and heat shock protein 9 (HSPA9). Direct binding with both interaction partners was confirmed by co-immunoprecipitation. We found that STK31 and HSPA9 bind MAGEG2 directly but not with each other. Interestingly, MAGEG2 reduced the kinase activity of STK31. Our study suggests that mouse MAGEG2 has at least two functions, including chaperone activity related to HSPA9 and regulation of pachytene spermatocyte-specific kinase, STK31. Altogether, our results provide the first information about MAGEG2 at the transcript and protein levels and suggest its potential molecular functions.

STK31 as novel biomarker of metastatic potential and tumorigenicity of colorectal cancer

Purpose

Colorectal cancer (CRC) is the fifth most common cause of cancer deaths in China and fourth worldwide. Metastatic dissemination of primary tumors is considered main cause for CRC related mortality. The serine–threonine kinase 31 (STK31) gene is a novel cancer testis (CT) antigen. It was found significantly highly expressed in gastrointestinal cancers. In our study we aimed to analyze the correlation between STK31 expression patterns and metastasization, tumor stage and grade in CRC patients.

RESULTS

Relative STK31 expression level was significantly higher in patients with lymph node metastasis. STK31 expression levels in primary tumorous tissues of metastatic patients were significantly higher than in ANCTs and in lymph nodes samples, both at the RNA level and the protein level.

Materials and Methods

Surgical specimens of cancerous tissues, paired with adjacent noncancerous tissues, and lymph nodes from 44 CRC cases with different clinicopathological features were collected. Expression of STK31 was detected and measured by immunohistochemistry and quantitative real-time polymerase chain reaction (QRT-PCR).

Conclusions

Our data suggest that STK31 might be a potential biomarker in detecting, monitoring and predicting the metastatic risk of colorectal cancer.

De Novo Transcriptome Analysis of the Common New Zealand Stick Insect Clitarchus hookeri (Phasmatodea) Reveals Genes Involved in Olfaction, Digestion and Sexual Reproduction

Phasmatodea, more commonly known as stick insects, have been poorly studied at the molecular level for several key traits, such as components of the sensory system and regulators of reproduction and development, impeding a deeper understanding of their functional biology. Here, we employ de novo transcriptome analysis to identify genes with primary functions related to female odour reception, digestion, and male sexual traits in the New Zealand common stick insect Clitarchus hookeri (White). The female olfactory gene repertoire revealed ten odorant binding proteins with three recently duplicated, 12 chemosensory proteins, 16 odorant receptors, and 17 ionotropic receptors. The majority of these olfactory genes were over-expressed in female antennae and have the inferred function of odorant reception. Others that were predominantly expressed in male terminalia (n = 3) and female midgut (n = 1) suggest they have a role in sexual reproduction and digestion, respectively. Over-represented transcripts in the midgut were enriched with digestive enzyme gene families. Clitarchus hookeri is likely to harbour nine members of an endogenous cellulase family (glycoside hydrolase family 9), two of which appear to be specific to the C. hookeri lineage. All of these cellulase sequences fall into four main phasmid clades and show gene duplication events occurred early in the diversification of Phasmatodea. In addition, C. hookeri genome is likely to express γ-proteobacteria pectinase transcripts that have recently been shown to be the result of horizontal transfer. We also predicted 711 male terminalia-enriched transcripts that are candidate accessory gland proteins, 28 of which were annotated to have molecular functions of peptidase activity and peptidase inhibitor activity, two groups being widely reported to regulate female reproduction through proteolytic cascades. Our study has yielded new insights into the genetic basis of odour detection, nutrient digestion, and male sexual traits in stick insects. The C. hookeri reference transcriptome, together with identified gene families, provides a comprehensive resource for studying the evolution of sensory perception, digestive systems, and reproductive success in phasmids.

RNA sequencing as a powerful tool in searching for genes influencing health and performance traits of horses

RNA sequencing (RNA-seq) by next-generation technology is a powerful tool which creates new possibilities in whole-transcriptome analysis. In recent years, with the use of the RNA-seq method, several studies expanded transcriptional gene profiles to understand interactions between genotype and phenotype, supremely contributing to the field of equine biology. To date, in horses, massive parallel sequencing of cDNA has been successfully used to identify and quantify mRNA levels in several normal tissues, as well as to annotate genes. Moreover, the RNA-seq method has been applied to identify the genetic basis of several diseases or to investigate organism adaptation processes to the training conditions. The use of the RNA-seq approach has also confirmed that horses can be useful as a large animal model for human disease, especially in the field of immune response. The presented review summarizes the achievements of profiling gene expression in horses (Equus caballus).

Transcriptome profiling of the testis reveals genes involved in spermatogenesis and marker discovery in the oriental fruit fly, Bactrocera dorsalis

The testis is a highly specialized tissue that plays a vital role in ensuring fertility by producing spermatozoa, which are transferred to the female during mating. Spermatogenesis is a complex process, resulting in the production of mature sperm, and involves significant structural and biochemical changes in the seminiferous epithelium of the adult testis. The identification of genes involved in spermatogenesis of Bactrocera dorsalis (Hendel) is critical for a better understanding of its reproductive development. In this study, we constructed a cDNA library of testes from male B. dorsalis adults at different ages, and performed de novo transcriptome sequencing to produce a comprehensive transcript data set, using Illumina sequencing technology. The analysis yielded 52 016 732 clean reads, including a total of 4.65 Gb of nucleotides. These reads were assembled into 47 677 contigs (average 443 bp) and then clustered into 30 516 unigenes (average 756 bp). Based on BLAST hits with known proteins in different databases, 20 921 unigenes were annotated with a cut-off E-value of 10(-5). The transcriptome sequences were further annotated using the Clusters of Orthologous Groups, Gene Orthology and the Kyoto Encyclopedia of Genes and Genomes databases. Functional genes involved in spermatogenesis were analysed, including cell cycle proteins, metalloproteins, actin, and ubiquitin and antihyperthermia proteins. Several testis-specific genes were also identified. The transcripts database will help us to understand the molecular mechanisms underlying spermatogenesis in B. dorsalis. Furthermore, 2913 simple sequence repeats and 151 431 single nucleotide polymorphisms were identified, which will be useful for investigating the genetic diversity of B. dorsalis in the future.

STK31/TDRD8, a germ cell-specific factor, is dispensable for reproduction in mice

Tudor domain containing (Tdrd) proteins that are expressed in germ cells are divided into two groups. One group, consisting of TDRD1, TDRKH, TDRD9 and TDRD12, function in piRNA biogenesis and retrotransposon silencing, while the other group including RNF17/TDRD4 and TDRD5-7 are required for spermiogenesis. These Tdrd proteins play distinct roles during male germ cell development. Here, we report the characterization of STK31/TDRD8 in mice. STK31 contains a tudor domain and a serine/threonine kinase domain. We find that STK31 is a cytoplasmic protein in germ cells. STK31 is expressed in embryonic gonocytes of both sexes and postnatal spermatocytes and round spermatids in males. Disruption of the tudor domain and kinase domain of STK31 respectively does not affect fertility in mice. Our data suggest that the function of STK31 may be redundant with other Tdrd proteins in germ cell development.

STK31(TDRD8) is dynamically regulated throughout mouse spermatogenesis and interacts with MIWI protein

Tudor-domain-containing proteins (TDRDs) are suggested to be critical regulators of germinal granules assembly involved in Piwi-interacting RNAs (piRNAs)-mediated pathways, of which associated components and the underlying functional mechanisms, however, remain to be elucidated. We herein characterized the expression pattern of STK31, a member of TDRDs subfamily (also termed as TDRD8), throughout spermatogenesis during mouse postnatal development. RT-PCR and Western blot verified its preferential expression in testis, but not in any other somatic tissues, in addition to embryonic stem cells. Immunofluorescent staining demonstrated that STK31 was confined to granules-like structures in mid-to-late spermatocyte cytoplasm and to acrosomal cap starting at steps 7-8 of spermatids. Furthermore, STK31 retained its localization to equatorial segment of acrosome during epididymal maturation, capacitation, and acrosome reaction. Co-immunoprecipitation assay in vivo and in vitro confirmed MIWI is a bona fide partner of STK31 in mice testes, in combination with LC/MS identification. We also discovered a group of heat shock proteins specifically associated with STK31 in vivo. Our findings suggest mouse STK31 could be a potential nuage-associated protein in the cytoplasm of mid-to-late spermatocytes and play pivotal roles related to fertilization.

First transcriptome of the testis-vas deferens-male accessory gland and proteome of the spermatophore from Dermacentor variabilis (Acari: Ixodidae)

Ticks are important vectors of numerous human diseases and animal diseases. Feeding stimulates spermatogenesis, mating and insemination of male factors that trigger female reproduction. The physiology of male reproduction and its regulation of female development are essentially a black box. Several transcriptomes have catalogued expression of tick genes in the salivary glands, synganglion and midgut but no comprehensive investigation has addressed male reproduction and mating. Consequently, a new global approach using transcriptomics, proteomics, and quantitative gene expression is needed to understand male reproduction and stimulation of female reproduction.

This first transcriptome to the reproductive biology of fed male ticks, Dermacentor variabilis, was obtained by 454 pyrosequencing (563,093 reads, 12,804 contigs). Gene Ontology (Biological Processes level III) recognized 3,866 transcripts in 73 different categories; spermiogenesis; spermatogenesis; peptidases, lipases and hydrolases; oxidative and environmental stress; immune defense; and protein binding. Reproduction-associated genes included serine/threonine kinase, metalloendoproteinases, ferritins, serine proteases, trypsin, cysteine proteases, serpins, a cystatin, GPCR and others. qRT-PCR showed significant upregulation from unfed versus fed adult male reproductive organs of zinc metalloprotease, astacin metalloprotease and serine protease, enzymes important in spermiogenesis and mating activity in insects, as well as a GPCR with the greatest similarity to a SIFamide receptor known to be important in regulating courtship behavior in Drosophila. Proteomics on these organs and the spermatophore by tryptic digestion/Liquid chromatography/Mass spectrometry/Mass spectrometry (LC/MS/MS) demonstrated expression of many of the same messages found by 454 sequencing, supporting their identification, and revealed differences in protein distribution in the reproductive system versus the spermatophore. We found Efα but no EF β in the transcriptome and neither of these proteins in the spermatophore. Thus, the previously described model for male regulation of female reproduction may not apply to other ticks. A new paradigm is needed to explain male stimulation of female tick reproduction.

Tdrd3 is a novel stress granule-associated protein interacting with the Fragile-X syndrome protein FMRP

Tudor domains are widespread among proteins involved in RNA metabolism, but only in a few cases their cellular function has been analyzed in detail. Here, we report on the characterization of the ubiquitously expressed Tudor domain containing protein Tdrd3. Apart from its Tudor domain, we show that Tdrd3 possesses an oligosaccharide/nucleotide binding fold (OB-fold) and an ubiquitin associated domain capable of binding tetra-ubiquitin. A set of biochemical experiments revealed an interaction of Tdrd3 with FMRP, the product of the gene affected in Fragile X syndrome, and its autosomal homologs FXR1 and FXR2. FMRP has been implicated in the translational regulation of target mRNAs and shown to be a component of stress granules (SG). We demonstrate that overexpression of Tdrd3 in cells induces the formation of SGs and as a result leads to its co-localization with endogenous FMRP in these structures. Interestingly, the disease-associated FMRP missense mutation I304N identified in a Fragile X patient severely impairs the interaction with Tdrd3 in biochemical experiments. We propose a contribution of Tdrd3 to FMRP-mediated translational repression and suggest that the loss of the FMRP-Tdrd3 interaction caused by the I304N mutation might contribute to the pathogenesis of Fragile X syndrome.