Results 11 to 20 of about 439,964 (240)
Sperm Competition and Sperm Length in Shorebirds [PDF]
The Condor, 1999 We investigated how sperm morphology varies across 16 species of shorebirds in the Scolopa- cidae, Charadriidae, and Jacanidae. Sperm were sig- nificantly longer in nonmonogamous than in socially monogamous species.
Johnson, Dominic D., Briskie, James V.
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Sperm design and sperm function [PDF]
Biology Letters, 2006 Spermatozoa vary enormously in their form and dimensions, both between and within species, yet how this variation translates into fertilizing efficiency is not known. Sperm swimming velocity is a key determinant of male fertilization success, but previous efforts to identity which sperm phenotypic traits are associated with swimming ...
Malo Valenzuela, Aurelio F. +5 more
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Sperm Viability and Sperm Competition in Insects [PDF]
Current Biology, 2002 Sperm quality plays an important role in vertebrates in determining which male has the advantage when two or more males compete to fertilize a female's ova. In insects, however, the importance of sperm quality has never been considered, despite sperm competition being widespread and well studied in this group.
Tim R. Birkhead, F.M Hunter
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Sperm Cholesterol Content Modifies Sperm Function and TRPV1-Mediated Sperm Migration [PDF]
International Journal of Molecular Sciences, 2021 Transient receptor potential channels-vanilloid receptor 1 (TRPV1) regulates thermotaxis in sperm-oriented motility. We investigated the role of membrane cholesterol (Chol) on TRPV1-mediated human sperm migration. Semen samples were obtained from five normozoospemic healthy volunteers.
De Toni L. +9 more
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By hook or by crook? Morphometry, competition and cooperation in rodent sperm [PDF]
, 2007 Background Sperm design varies enormously across species and sperm competition is thought to be a major factor influencing this variation. However, the functional significance of many sperm traits is still poorly understood.
AH Harcourt +40 more
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Molecular and Cellular Endocrinology, 2006 Thermotaxis--movement directed by a temperature gradient--is a prevalent process, found from bacteria to human cells. In the case of mammalian sperm, thermotaxis appears to be an essential mechanism guiding spermatozoa, released from the cooler reservoir site, towards the warmer fertilization site.
Bahat, Anat, Eisenbach, Michael
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Sperm competition and the evolution of sperm design in mammals [PDF]
BMC Evolutionary Biology, 2011 AbstractBackgroundThe influence of sperm competition upon sperm size has been a controversial issue during the last 20 years which remains unresolved for mammals. The hypothesis that, when ejaculates compete with rival males, an increase in sperm size would make sperm more competitive because it would increase sperm swimming speed, has generated ...
Maximiliano Tourmente +3 more
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The evolution of sperm morphometry in pheasants [PDF]
, 2007 Postcopulatory sexual selection is thought to be a potent evolutionary force driving the diversification of sperm shape and function across species. In birds, insemination and fertilisation are separated in time and sperm storage increases the duration
Birkhead, T.R. +5 more
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Current Biology, 2012 (Uploaded by Plazi for the Bat Literature Project) No abstract provided.
Teri J. Orr, Marlene Zuk
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Investigative Genetics, 2014 Copenhagen is as flat as the proverbial pan-cake. A good way to appreciate this is to visit the Rundetaarn, a 35 m tower whose summit is reached by a spiral ramp designed in the 17th century to accommodate a horse and cart carrying books to its elevated library, and in more recent times inviting the competitive attention of puffing middle-aged blokes ...
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