Sperm motility-initiating substance (SMIS) is a key protein for internal fertilization of the newt, Cynops pyrrhogaster, and commonly enhances forward sperm motility in some amphibian species, including external fertilizers. SMIS action varies among different species in correlation with a species-specific reproductive environment. In the present study, we identified the gene of C. ensicauda SMIS (CeSMIS) and examined the mechanism of SMIS action with reference to that of the closely related Cynops species. The CeSMIS was identified by a 176-amino acid sequence including seven amino acids critical for the initiation of sperm motility. The amino acid sequence showed 91% homology to the whole sequence of C. pyrrhogaster SMIS (CpSMIS). By immunostaining with an anti-CpSMIS antibody, CeSMIS was shown to be localized in the outer layer of the egg jelly. A peptide presenting the active site of SMIS was observed to bind to the axial rod of the midpiece in C. ensicauda sperm. The localization and binding patterns of CeSMIS were fundamentally similar to those of CpSMIS. However, the SMIS peptide did not induce forward motility of C. ensicauda sperm, although it induced a fast wave of the undulating membrane. Forward sperm motility was induced in the egg jelly extract containing CeSMIS. These results suggest that the mechanism of initiation of sperm motility is differentiated between C. ensicauda and C. pyrrhogaster.
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http://dx.doi.org/10.1002/mrd.22849 | DOI Listing |
Environ Sci Technol
January 2025
College of Environment and Climate, Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou 510632, China.
Although epidemiological studies have explored the association between poly- and perfluoroalkyl substances (PFAS) concentrations and semen quality, existing findings are often inconsistent. Our work aimed to explore the association of PFAS in plasma and semen with repeated measures of semen quality parameters in healthy adults. Plasma was collected at the initial recruitment and semen was collected at least once within five predetermined intervals during an approximately 3-month period.
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January 2025
Department of Biochemistry and Molecular Biophysics, Washington University in St. Louis, School of Medicine, St. Louis, MO, USA.
Reproduction, development and homeostasis depend on motile cilia, whose rhythmic beating is powered by a microtubule-based molecular machine called the axoneme. Although an atomic model of the axoneme is available for the alga Chlamydomonas reinhardtii, structures of mammalian axonemes are incomplete. Furthermore, we do not fully understand how molecular structures of axonemes vary across motile-ciliated cell types in the body.
View Article and Find Full Text PDFBMJ Open
December 2024
Department of Physiology, University of Sri Jayewardenepura, Nugegoda, Sri Lanka
Introduction: Male infertility, defined as the inability to impregnate a fertile female, arises from various factors, among which sperm motility plays a pivotal role in determining reproductive potential. Seminal plasma, a complex fluid comprising diverse proteins, serves to nourish and support sperm, thereby facilitating their function within the female reproductive tract for successful conception. Normozoospermia denotes normal sperm motility in males, whereas asthenozoospermia indicates reduced sperm motility.
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December 2024
Laboratory of Reproductive Endocrinology, Graduate School of Integrated Sciences for Life, Hiroshima University, 1-4-4, Kagamiyama, Higashihiroshima, Hiroshima, 7398528, Japan. Electronic address:
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December 2024
Department of Poultry Science, University of Georgia, Athens, GA 30602-2772, USA.
Semen cryopreservation is essential for preserving genetic resources and enabling artificial insemination in poultry breeding. However, avian sperm is known to experience detrimental changes during the freezing process. Telmisartan, an angiotensin-II receptor antagonist recognized for its antioxidant properties and ability to activate AMP-activated protein kinase (AMPK), was hypothesized to improve post-thaw semen quality by enhancing mitochondrial function and providing antioxidant protection to sperm.
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