Extracellular vesicle research in reproductive science— Paving the way for clinical achievements

Mammalian conception involves a multitude of reciprocal interactions via a molecular dialogue between mother and conceptus. Extracellular vesicles (EVs) are secreted membrane-encapsulated particles that mediate cell-to-cell communication in various contexts. EVs, which are present in seminal, follicular, oviductal, and endometrial fluids, as well as in embryo secretions, carry molecular constituents that impact gamete maturation, fertilization, early embryo development, and embryo-maternal communication. The distribution, concentration, and molecular cargo of EVs are regulated by steroid hormones and the health status of the tissue of origin, and thus are influenced by menstrual phase, stage of conception, and the presence of infertility-associated diseases. EVs have been recognized as a novel source of biomarkers and potential reproductive medicine therapeutics, particularly for assisted reproductive technology (ART). There are still many technological and scientific hindrances to be overcome before EVs can be used in clinical diagnostic and therapeutic ART applications. Issues to be resolved include the lack of standardized measurement protocols and an absence of absolute EV quantification technologies. Additionally, clinically suitable and robust EV isolation methods have yet to be developed. In this review, we provide an overview of EV-mediated interactions during the early stages of reproduction from gamete maturation to embryo implantation and then outline the technological progress that must be made for EV applications to be translated to clinical settings.

Hormonal, metabolic and clinical manifestations of the climacteric syndrome as a marker of ecological trouble in the region

In the early 90s, academician E.K. Ailamazyan formulated the main provisions of general ecological reproductive science and the concept arising from them, according to which indicators of the reproductive function of women can act as criteria for assessing the ecological situation in the region. In 1995, an employee of the Institute of Obstetrics and Gynecology. D.O. Ott.

A Poor Research Landscape Hinders the Progression of Knowledge and Treatment of Reproductive Diseases

Reproductive diseases have gone under the radar for many years, resulting in insufficient diagnostics and treatments. Infertility rates are rising, preeclampsia claims over 70 000 maternal and 500 000 neonatal lives globally per year, and endometriosis affects 10% of all reproductive-aged women but is often undiagnosed for many years. Policy changes have been enacted to mitigate the gender inequality in research investigators and subjects of medical research. However, the disparities in reproductive research advancement still exist. Here, we analyzed the reproductive science research landscape to quantify the gravity of the current situation. We find that non-reproductive organs are researched 5-20 times more annually than reproductive organs, leading to an exponentially increasing relative knowledge gap in reproductive sciences. Additionally, reproductive organs (breast and prostate) are mainly researched when there is a disease focus, leading to a lack of basic understanding of the reproductive organs. This gap in knowledge affects reproductive syndromes and other bodily systems and research areas, such as cancer biology and regenerative medicine. Current researchers, funding organizations and educators must take action to combat this longstanding disregard of reproductive science.

Opportunities and Limitations for Reproductive Science in Species Conservation

Reproductive science in the context of conservation biology is often understood solely in terms of breeding threatened species. Although technologies developed primarily for agriculture or biomedicine have a potentially important role in species conservation, their effectiveness is limited if we regard the main objective of animal conservation as helping to support populations rather than to breed a small number of individuals. The global threats facing wild species include the consequences of climate change, population growth, urbanization, atmospheric and water pollution, and the release of chemicals into the environment, to cite but a few. Reproductive sciences provide important and often unexpected windows into many of these consequences, and our aim here is both to demonstrate the breadth of reproductive science and the importance of basic knowledge and to suggest where some of the insights might be useful in mitigating the problems. Expected final online publication date for the Annual Review of Animal Biosciences, Volume 10 is February 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Physiological factors influencing female fertility in birds

Fertility is fundamental to reproductive success, but not all copulation attempts result in a fertilized embryo. Fertilization failure is especially costly for females, but we still lack a clear understanding of the causes of variation in female fertility across taxa. Birds make a useful model system for fertility research, partly because their large eggs are easily studied outside of the female's body, but also because of the wealth of data available on the reproductive productivity of commercial birds. Here, we review the factors contributing to female infertility in birds, providing evidence that female fertility traits are understudied relative to male fertility traits, and that avian fertility research has been dominated by studies focused on Galliformes and captive (relative to wild) populations. We then discuss the key stages of the female reproductive cycle where fertility may be compromised, and make recommendations for future research. We particularly emphasize that studies must differentiate between infertility and embryo mortality as causes of hatching failure, and that non-breeding individuals should be monitored more routinely where possible. This review lays the groundwork for developing a clearer understanding of the causes of female infertility, with important consequences for multiple fields including reproductive science, conservation and commercial breeding.