Molecular Reproduction and Development最新文献

In vitro maturation (IVM) is a form of assisted reproductive technology (ART) applied to obtain mature oocytes in culture. Decline in IVM success rates by age has led consideration of novel approaches based on cellular dynamics. Our aim was to achieve proteostasis in old bovine oocytes from 13 to 16-year-old bovine with a lower potential for fertilization. Lysosomal activation was achieved through increasing concentrations of proton pump activators PIP2 (0.1, 0.5, 1, and 5 μM), PMA (0.1, 1, 10, and 50 μM), and DOG (0.1, 1, 10, and 50 μM) at 6, 12, 18, and 24 h of IVM in old bovine oocytes. Morphological analysis was performed and IVM rates were determined. DQ-Red BSA was applied to live oocytes to determine proteolytic activation while lysosome density was determined by Lysotracker probe. Protein carbonylation was detected through oxyblot analysis. Polar body extrusion (PBE), through which a haploid nonfunctional polar body is released in the perivitelline space after completion of the first meiotic division, was observed in PIP2-0.1 μM, -0.5μM-6h; PIP2-5μM-12h; PMA-0.1μM-18h; PIP2-0.1μM, -0.5μM-24h groups. Oocyte diameter was the highest in DOG-1μM-6h, PMA-0.1μM-12h, PIP2-1μM-18h, and PIP2-0.5μM-24h groups. Morphological scores of oocytes were higher in young and old control groups. PIP2, PMA, and DOG affected oocyte quality positively after 6 h of IVM yielding in oocyte scores similar to the control group oocytes. However, they had a negative impact on the oocyte scores in longer periods of IVM, except for lower doses PMA (0.1 and 1 μM) at 12 h and PIP2 (0.5 μM) and PMA (0.1 μM) at 18 h, which were able to maintain the scores relatively closer to the control oocytes. Proteolytic activation was achieved in all groups at 6 h of culture. At all other time points PIP2 and PMA groups showed a better response to proteolytic activation. Lysosome density was increased in PIP2-5μM-6h; PIP2-0.1μM, -1μM-12h; PIP2-1μM, -5μM-18h as well as PMA-0.1μM-6h; PMA-1μM, -10μM-12h; PMA-1μM-18h; DOG-50μM-6h and DOG-0.1μM-12h. Protein carbonylation was the lowest in PIP2-0.1 μM groups at 12, 18, and 24 h. This study suggests that proton pump activators PIP2 and PMA was found to have a positive impact on IVM in terms of both morphological scores and proteolytic activation in a time and dose dependant manner.

A role for the plasminogen activator (PA) system has been postulated in mammalian gonads, considering the complex process of morphogenesis these organs undergo during their development. Our results show that mouse Sertoli cells under basal conditions produce both types of PA, tissue-type PA (tPA) and urokinase-type PA (uPA), and hormonal treatments increase the production of both enzymes. The increased enzyme secretion does not correlate with a parallel increase in their mRNAs. However, the proteolytic activity results from a balance between enzyme activity and inhibitors. Hormonal stimulation decreased the expression of the inhibitor PAI-1, suggesting that the increase in proteolytic activity might depend on the decreased production of PAI-1. The expression of the two enzymes and their inhibitor depends on the seminiferous epithelium stage. We observed higher uPA mRNA levels at stages VII-VIII and IX-XII, tPA peaks at stages VII-VIII, and PAI-1 mRNA levels decreased at stages VII-VIII and IX-XII. The testes from mice lacking the uPA gene (uPA^-/-) presented statistically smaller sizes and weights. Histological analysis of uPA^-/-animals showed tubular morphology defects and atypical residual bodies (RB), suggesting a defect in Sertoli cell phagocytosis. Moreover, we show lower sperm concentration and motility in uPA^-/- mice. These data suggested an effective deficiency of testicular development in the absence of uPA.

Echinoderms exhibit a wide range of reproductive strategies as adaptations to variable environments. The processes of gonadal development, germ cell differentiation, and spermatogenesis in echinoderms are crucial physiological processes that warrant further in-depth exploration. This review systematically summarizes research from early basic sciences to recent studies on male gonadal development and spermatogenesis, encompassing morphology, histology, physiology, cell biology, developmental biology, and evolutionary biology. We introduce the structural and cellular similarities and differences among model or non-model organisms from five classes of echinoderms to provide insights for future comparative research between higher vertebrates and lower organisms. The regulatory systems involved in echinoderm spermatogenesis are described from various aspects including nutritional supply, environmental factors, neurological influences, endocrinological influences, and hormonal influences. This article aims to elucidate gonadal development and spermatogenesis in echinoderms-organisms at unique evolutionary nodes-providing valuable materials for studying adaptive evolution and developmental biology. Additionally, a comprehensive summary of characterized genes and gene markers associated with testes development and spermatogenesis is provided as useful information for future systematic studies on cell subpopulations. Future studies can focus on molecular changes associated with chromatin remodeling during germ cell development, cellular differentiation, and intercellular communication mediated by receptor-ligand interactions, to further our understanding of biological processes and regulatory networks involved in echinoderm gonadal development and spermatogenesis.

Odourant receptors (ORs) are not restricted only to the nose, but also occur in many other organs and tissues, including the reproductive system. In fact, ORs are the most heavily expressed in testis than in any other extra-nasal tissue. Accumulating evidence suggests that olfactory and reproductive systems are both structurally and functionally linked and that these interconnections can influence various aspects of reproduction. In this article, we first review our current understanding of these interconnections and then collate accumulated evidence on the presence of ORs in the male reproductive system and sperm cells. We then investigate the potential role of female reproductive tract odourants in sperm chemotaxis and selection. Finally, since the existing evidence especially for sperm odor sensing capability and its physiological function are controversial, we also review potential reasons for the controversy and propose some ways to resolve the debate. Collectively, we conclude that reproductive odourant signaling may play an important, although currently largely unclear role in many key processes directly related to male fertility. However, since we lack holistic understanding of the functional significance of ORs and odor sensing pathways of the male reproductive system, more empirical research is warranted.

The emergence of the earliest cell lineages in mammalian embryos is a complex process that utilizes an extensive network of chromatin regulators, transcription factors, cell polarity regulators, and cellular signaling pathways. These factors and pathways operate over a protracted period of time as embryos cleave, undergo compaction, and form blastocysts. The first cell fate specification event separates the pluripotent inner cell mass from the trophectoderm lineage. The second event separates pluripotent epiblast from hypoblast. This review summarizes over 50 years of study of these early lineage forming events, addressing the complexity of the network of interacting molecules, cellular functions and pathways that drive them, interspecies differences, and aspects of these mechanisms that likely underlie their high susceptibility to disruption by numerous environmental factors that can compromise embryo viability, such as maternal health and diet, environmental toxins, and other stressors.

This review focuses on the contribution of the late David Garbers to chemotaxis of sperm, in particular from sea urchin. We will describe his discovery of chemotactic peptides and their cognate receptors, his discovery of a sperm-specific, unique Na⁺/H⁺ exchanger that represents a chimera between a solute carrier (SLC) and an ion channel. Finally, we will discuss his contributions to the understanding of cAMP signaling in sperm via soluble adenylyl cyclase (sAC) and its control by Ca²⁺ ions.

The development of novel non-hormonal male contraceptives represents a pivotal frontier in reproductive health, driven by the need for safe, effective, and reversible contraceptive methods. This comprehensive review explores the genetic underpinnings of male fertility, emphasizing the crucial roles of specific genes and structural variants (SVs) identified through advanced sequencing technologies such as long-read sequencing (LRS). LRS has revolutionized the detection of structural variants and complex genomic regions, offering unprecedented precision and resolution over traditional next-generation sequencing (NGS). Key genetic targets, including those implicated in spermatogenesis and sperm motility, are highlighted, showcasing their potential as non-hormonal contraceptive targets. The review delves into the systematic identification and validation of male reproductive tract-specific genes, utilizing advanced transcriptomics and genomics studies with validation using novel knockout mouse models. We discuss the innovative application of small molecule inhibitors, developed through platforms like DNA-encoded chemistry technology (DEC-Tec), which have shown significant promise in preclinical models. Notable examples include inhibitors targeting serine/threonine kinase 33 (STK33), soluble adenylyl cyclase (sAC), cyclin-dependent kinase 2 (CDK2), and bromodomain testis associated (BRDT), each demonstrating nanomolar affinity and potential for reversible and specific inhibition of male fertility. This review also honors the contributions of Dr. David L. Garbers whose foundational work has paved the way for these advancements. The integration of genomic, proteomic, and chemical biology approaches, supported by interdisciplinary collaboration, is poised to transform male contraceptive development. Future perspectives emphasize the need for continued innovation and rigorous testing to bring these novel contraceptives from the laboratory to clinical application, promising a new era of male reproductive health management.

Bioenergetics plays a crucial role in sperm functions, including motility, capacitation-related protein modifications, oocyte recognition and interaction, all of which are essential for fertilization. Sperm metabolism is recognized as flexible, responding to environmental cues and energetic demands during ejaculation, the journey along the female tract, and until fertilization. Recent studies suggest that sperm metabolic functions are relevant beyond fertilization and may influence zygote and embryo development, impacting paternal-derived effects on offspring development and health. In recent years, sperm metabolic functions and homeostasis have gained increasing interest in male reproduction research. Given the crucial implications of sperm metabolism on fertility-related processes, this field is of interest not only in human male fertility but also in livestock research, semen conservation, and assisted reproductive techniques. Newly developed assessment tools are allowing a better understanding of sperm metabolism under different conditions and identifying species-specific peculiarities. This review aims to discuss the current knowledge of mammalian sperm metabolism, focusing on species-specific features, changes during the sperm journey, and potential contributions to translational research and reproductive biotechnologies. Furthermore, we propose future perspectives on sperm bioenergetics research.