Polyspermy - Wikipedia
In biology, polyspermy describes the fertilization of an egg by more than one sperm. Diploid organisms normally contain two copies of each chromosome, one from each parent. The cell resulting from polyspermy, on the other hand, contains three or more copies of each chromosome—one from the egg and one each from multiple sperm.
Gamete Fusion and the Prevention of Polyspermy
The entrance of multiple sperm— polyspermy —leads to disastrous consequences in most organisms. In the sea urchin, fertilization by two sperm results in a triploid nucleus, in which each chromosome is represented three times rather than twice.
Polyspermy - an overview | ScienceDirect Topics
Polyspermy is a lethal condition where more than one sperm nucleus interacts with the female nucleus. This article looks at how animals avoid this condition in nature and shows that sperm numbers are regulated in various ways to ensure low sperm–oocyte ratios at …
Polyspermy - an overview | ScienceDirect Topics
In general, the entry of more than two spermatozoa into the egg cytoplasm, referred to as polyspermy, causes aberrant effects on meiosis completion or embryo development and hence embryonic death, due mainly to excess male centrosomes delivered into the egg.
Polyspermy - an overview | ScienceDirect Topics
Polyspermy occurs when two or more spermatozoa enter the cytoplasm of a single oocyte. In mammals this usually leads to abnormal fertilization and embryonic death, but in some other taxonomic groups (e.g., amphibians) it is perfectly normal.
The biology and evolution of polyspermy: insights from cellular …
Polyspermy occurs when the oocyte is penetrated by more than one sperm and can be pathological because an excess of centrosomes compromises development. However, in some taxa, multiple sperm enter the egg with no apparent adverse effect on zygote viability.
Polyspermy prevention: facts and artifacts? - PMC - PubMed …
Polyspermy is a fact in aged oocytes in vivo and in vitro, whereas the concept of “polyspermy-blocking mechanisms” in mammalian oocytes is mainly based on experiments in vitro using oocytes deprived of their external coats.
Molecular Reproduction & Development - Wiley Online Library
2020年3月27日 · Polyspermy is a major cause of triploidy with up to 80% of triploid conceptuses being the result of dispermic fertilization. The mammalian female reproductive tract regulates the number of sperm that reach the site of fertilization, but mammals also utilize egg-based blocks to …
Two pathways regulate cortical granule translocation to …
2016年12月19日 · Inhibiting cortical granule translocation severely impaired the block to sperm entry, suggesting that translocation defects could contribute to miscarriages that are caused by polyspermy.
Biology of Polyspermy in IVF and its Clinical Indication
2013年9月6日 · Extensive studies and reviews have summarized the polyspermy block in mice and large animals. This review focuses on new discoveries, oocyte quality, multiploidy, ability of embryo’s self-correction, and the clinical relevance.