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Sperm competition games: sperm selection by females
Journal of Theoretical Biology, 2003We analyse a co-evolutionary sexual conflict game, in which males compete for fertilizations (sperm competition) and females operate sperm selection against unfavourable ejaculates (cryptic female choice). For simplicity, each female mates with two males per reproductive event, and the competing ejaculates are of two types, favourable (having high ...
M A, Ball, G A, Parker
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Sperm competition influences sperm size in mammals
Proceedings of the Royal Society of London. Series B: Biological Sciences, 1991Among mammals sperm competition leads to selection for increased sperm numbers but it is not known whether it also leads to changes in sperm size. Two contrasting theoretical predictions have been made. The first hypothesis relies on the assumption that there is a trade-off between sperm numbers and sperm size and predicts that, in species confronting ...
M, Gomendio, E R, Roldan
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Early sperm-egg interaction after sperm microinjection
Reproduction, Fertility and Development, 1994The early events of sperm-egg interaction occurring 1-3 h after multiple sperm injection into the perivitelline space (PVS) and after direct injection into the ooplasm of human oocytes are reported. The sperm acrosome reaction occurred in the PVS but was not detected within the ooplasm.
A H, Sathananthan +5 more
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Sperm centriole disfunction and sperm immotility
Molecular and Cellular Endocrinology, 2000The two main causes of complete or nearly complete asthenozoospermia are necrozoospermia (presence of only non-viable spermatozoa) and the different ultrastructural abnormalities of spermatozoa. Ultrastructural alterations may affect also the function of the sperm centrosome, which can result in impaired motility.
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Sperm size and sperm competition in birds
Proceedings of the Royal Society of London. Series B: Biological Sciences, 1992In a sample of 20 species of North American passerine birds we found no relation between sperm size and mating system like that previously reported in mammals (Gomendio & Roldan (Proc. R. Soc. Lond. B 243, 181 (1991)). Instead, we found a positive correlation between sperm length and the length of female sperm storage tubules (SSTS) and a negative ...
J V, Briskie, R, Montgomerie
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Sperm‐sperm associations in the loris epididymis
Gamete Research, 1987AbstractIn a few mammals, the passage of maturing spermatozoa through the epididymis is characterized by development of persistent associations between one or more neighboring cells over the acrosomal region. The converse situation is described here in the loris, Nycticebus coucang, a prosimian primate.
D M, Phillips, J M, Bedford
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Sperm competition games: sperm size and sperm number under adult control
Proceedings of the Royal Society of London. Series B: Biological Sciences, 1993Evolutionary games of sperm competition in which two males mate with the same female have previously considered sperm size to be fixed at some (small) constant level. Although male gametes in multicellular organisms are typically small compared with ova, they vary greatly both between and within groups, and sperm size sometimes correlates with the ...
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Sperm Selection: Effect on Sperm DNA Quality
2013The selection of spermatozoa without DNA fragmentation and chromosomal diseases prior to assisted reproductive techniques helps to optimize the outcome of the treatment; in particular, sperm selection prior to in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) is crucial.
Lodovico, Parmegiani +2 more
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SPERM COMPETITION AND ITS EVOLUTIONARY CONSEQUENCES IN THE INSECTS
, 1970Geoff A. Parker
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