Seiya Oura

University of Texas Southwestern Medical Center | UT Southwestern · Department of Molecular Biology

Sperm proteins undergo post-translational modifications during sperm transit through the epididymis to acquire fertilizing ability. We previously reported that the genomic region coding Pate family genes is key to the proteolytic processing of the sperm membrane protein ADAM3 and male fertility. This region contains nine Pate family genes (Pate5–13...

Recent advances in human blastoids have opened new avenues for modeling early human development and implantation. One limitation of our first protocol for human blastoid generation was relatively low efficiency. We now report an optimized protocol for the efficient generation of large quantities of high-fidelity human blastoids from naive pluripote...

In vitro stem cell models that replicate human gastrulation have been generated, but they lack the essential extraembryonic cells needed for embryonic development, morphogenesis, and patterning. Here, we describe a robust and efficient method that prompts human extended pluripotent stem cells to self-organize into embryo-like structures, termed per...

Early embryo development is a highly dynamic process that plays a crucial role in determining the health and characteristics of an organism. For many years, embryonic and extraembryonic stem cell lines representing various developmental stages have served as valuable models for studying early embryogenesis. As our understanding of stem cell culture...

The mammalian spermatozoa produced in the testis require functional maturation in the epididymis for their full competence. Epididymal sperm maturation is regulated by lumicrine signalling pathways in which testis-derived secreted signals relocate to the epididymis lumen and promote functional differentiation. However, the detailed mechanisms of lu...

Spermatozoa have a streamlined shape to swim through the oviduct to fertilize oocytes. To become svelte spermatozoa, spermatid cytoplasm must be eliminated in several steps including sperm release, which is part of spermiation. Although this process has been well observed, the molecular mechanisms that underlie it remain unclear. In male germ cells...

Purpose: Microscopic testicular sperm extraction is the most effective treatment for NOA, but the sperm retrieval rate is low and depends on testicular maturity. However, there are limited useful tests to assess testicular maturity. Chemical exchange saturation transfer (CEST) imaging is a new magnetic resonance imaging (MRI) technique that can im...

Background: TSN (translin), also called TB-RBP (testis brain RNA-binding protein), binds to TSNAX (translin-associated factor X) and is suggested to play diverse roles such as RNA metabolism and DNA damage response. TSNAXIP1 (Tsnax interacting protein 1) was identified as a TSNAX interacting protein using a yeast two-hybrid system, but its functio...

Characterization of protein–protein interactions (PPI) is a key to understanding the functions of proteins of interest. Recently developed proximity-dependent biotin identification (BioID) has been actively investigated as an alternative PPI mapping method because of its usefulness in uncovering transient PPI. Here, as an example of proximity label...

Gene modification technology has long been beneficial for unraveling the mystery of biological phenomena. Thus, the advent of the clustered regularly interspaced short palindromic repeats (CRISPR)/ CRISPR-associated (Cas) 9 system was a game-changer in biological research because of its efficiency and simplicity of design. This review article first...

Meiosis is a hallmark event in germ cell development that accompanies sequential events executed by numerous molecules. Therefore, characterization of these factors is one of the best strategies to clarify the mechanism of meiosis. Here, we report tripartite motif-containing 41 (TRIM41), a ubiquitin ligase E3, as an essential factor for proper meio...

The process of sperm-egg fusion is critical for successful fertilization, yet the underlying mechanisms that regulate these steps have remained unclear in vertebrates. Here, we show that both mouse and zebrafish DCST1 and DCST2 are necessary in sperm to fertilize the egg, similar to their orthologs SPE-42 and SPE-49 in C. elegans and Sneaky in D. m...

Meiosis is a hallmark event in germ cell development that accompanies sequential chromosome events executed by numerous molecules. Therefore, characterization of these factors is one of the best strategies to clarify the mechanism of meiosis. Here, we report tripartite motif-containing 41 (TRIM41), a ubiquitin ligase E3, as an essential factor for...

The acrosome is a cap-shaped, Golgi-derived membranous organelle that is located over the anterior of the sperm nucleus and highly conserved throughout evolution. Although morphological changes during acrosome biogenesis in spermatogenesis have been well described, the molecular mechanism underlying this process is still largely unknown. Family wit...

Significance Calcineurin is a target of immunosuppressive drugs such as cyclosporine A and tacrolimus. In the immune system, calcineurin interacts with NFAT via the PxIxIT motif to activate T cells. In contrast, little is known about the proteins that interact with a testis-enriched calcineurin that is essential for sperm motility and male fertilit...

The clustered regularly interspaced palindromic repeats (CRISPR)/Cas9 system is a research hotspot in gene therapy. However, the widely used Streptococcus pyogenes Cas9 (WT-SpCas9) requires an NGG protospacer adjacent motif (PAM) for target recognition, thereby restricting targetable disease mutations. To address this issue, we recently reported an...

Meiosis is a cell division process with complex chromosome events where various molecules must work in tandem. To find meiosis-related genes, we screened evolutionarily conserved and reproductive tract-enriched genes using the CRISPR/Cas9 system and identified potassium channel tetramerization domain containing 19 ( Kctd19 ) as an essential factor...

The process of sperm-egg fusion is critical for successful fertilization, yet the underpinning mechanisms that regulate these steps have remained unclear in vertebrates. Here, we show that both mouse and zebrafish DCST1 and DCST2 are necessary in sperm to fertilize the egg, similar to their orthologs SPE-42 and SPE-49 in C. elegans and Sneaky in D....

Meiosis is a cell division process with complex chromosome events where various molecules must work in tandem. To find meiosis-related genes, we screened evolutionarily conserved and reproductive tract-enriched genes using the CRISPR/Cas9 system and identified potassium channel tetramerization domain containing 19 ( Kctd19 ) as an essential factor...

Significance Although formation of the mitochondrial sheath is a critical process in the formation of mature spermatozoa, the molecular mechanisms involved in mitochondrial sheath genesis remain unclear. Using gene-manipulated mice, we discovered that ARMC12 regulates spatiotemporal “sperm mitochondrial dynamics” during mitochondrial sheath formati...

The flagellum is essential for sperm motility and fertilization in vivo. The axoneme is the main component of the flagella, extending through its entire length. An axoneme is comprised of two central microtubules surrounded by nine doublets, the nexin-dynein regulatory complex, radial spokes, and dynein arms. Failure to properly assemble components...

Spermatogenesis is a complex process of sperm generation, including mitosis, meiosis, and spermiogenesis. During spermiogenesis, histones in post-meiotic spermatids are removed from chromatin and replaced by protamines. Although histone-to-protamine exchange is important for sperm nuclear condensation, the underlying regulatory mechanism is still p...

Significance The sperm−oocyte fusion step is important to transport the male genome into oocytes. So far, IZUMO1 and FIMP have been identified as fusion-related proteins in spermatozoa, but the molecular mechanisms underpinning sperm−oocyte fusion and all of the proteins required for this essential process remain unclear. In this study, using CRISP...

Globozoospermia (sperm with an abnormally round head shape) and asthenozoospermia (defective sperm motility) are known causes of male infertility in human patients. Despite many studies, the molecular details of the globozoospermia etiology are still poorly understood. Serine-rich single pass membrane protein 1 (Ssmem1) is a conserved testis-specif...

Kinesin is a molecular motor that moves along microtubules. Kinesin family member 9 (KIF9) is evolutionarily conserved and expressed strongly in mouse testis. In the unicellular flagellate Chlamydomonas, KLP1 (ortholog of KIF9) is localized to the central pair microtubules of the axoneme and regulates flagellar motility. In contrast, the function o...

In mammals, more than 2,000 genes are specifically or abundantly expressed in testis, but gene knockout studies revealed several are not individually essential for male fertility. Tesmin (Metallothionein-like 5; Mtl5) was originally reported as a testis-specific transcript that encodes a member of the CXC motif containing metallothionein family. La...

Significance While the emergence of gene modification technologies has produced major discoveries in biomedical sciences, the recent development of the CRISPR/Cas9 system has dramatically altered the trajectory of phenotypic analysis in animal models. In this study, we identified male-specific gene clusters ( Cst and Pate ) and family genes ( Gdpd...

High throughput transcriptomics and proteomics approaches have recently identified a large number of germ cell-specific genes with many that remain to be studied through functional genetics approaches. Serine proteases (PRSS) constitute nearly one-third of all proteases, and, in our bioinformatics screens, we identified many that are testis-specifi...

More than 1,000 genes are predicted to be predominantly expressed in mouse testis, yet many of them remain unstudied in terms of their roles in spermatogenesis and sperm function and their essentiality in male reproduction. Since individually indispensable factors can provide important implications for the diagnosis of genetically-related idiopathi...

Seminal vesicle secretions (SVSs), together with spermatozoa, are ejaculated into the female reproductive tract. SVS7, also known as PATE4, is one of the major SVS proteins found in the seminal vesicle, copulatory plug, and uterine fluid after copulation. Here, we generated Pate4 knockout (-/-) mice and examined the detailed function of PATE4 on ma...

Expanding the targeting space of Cas9 CRISPR-Cas9 associates with a guide RNA to target and cleave a specific DNA site next to a protospacer adjacent motif (PAM). Streptococcus pyogenes Cas9 (SpCas9), the one most often used for genome editing, only recognizes the NGG sequence (where N is any nucleobase) as the PAM, which restricts regions in the g...

The CRISPR/Cas9 system can efficiently introduce biallelic mutations in ES cells (ESCs), and its application with fluorescently-tagged ESCs enables phenotype analysis in chimeric mice. We have utilized ESCs that express EGFP in the cytosol and acrosome [EGR-G101 129S2 x (CAG/Acr-EGFP) B6] in previous studies; however, the EGFP signal in the sperm c...

Retinoids exert antitumor effects through the retinoic acid receptor α (RARα). In the present study, we sought to identify the factors involved in the RARα-mediated transcriptional regulation of the tumor suppressor gene and the tissue factor pathway inhibitor 2 (TFPI2) in hepatocellular carcinoma (HCC). All-trans-retinoic acid (ATRA) was used in t...