Results 11 to 20 of about 726,910 (390)

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.
Briskie, J V, Johnson, D D P
core   +4 more sources

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., Gomendio, Montserrat, Garde, Julián, Lang-Lenton, Barbara, Soler, Ana J, R.S. Roldán, Eduardo   +5 more
openaire   +4 more sources

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
openaire   +4 more sources

Three cases of sperm immobility for intracytoplasmic sperm injection using testicular sperm

IJU Case Reports
Introduction Sperm immobility is a condition in which sperm are viable but not motile. We reported three patients with sperm immobility, who underwent testicular sperm extraction‐intracytoplasmic sperm injection.
Noboru Mimura, Teppei Takeshima, Shun Aoki, Tomoki Saito, Jurii Karibe, Yasushi Yumura   +5 more
doaj   +3 more sources

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., Sabovic I., De Filippis V., Acquasaliente L., Peterle D., Guidolin D., Sut S., Di Nisio A., Foresta C., Garolla A.   +9 more
openaire   +3 more sources

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, AJ Holloway, BGM Jamieson, BGM Jamieson, CM Lessells, D Haig, DJ Hosken, DM Woolley, ERS Roldan, F Hayashi, FJ Rohlf, FJ Rohlf, GA Parker, GA Parker, Harry D.M. Moore, HDM Moore, HDM Moore, J Cohen, J Cohen, J Sivinski, L McGregor, M Pagel, MJ Anderson, MJ Anderson, RP Freckleton, RR Snook, RS Voss, S Ferson, S Pitnick, SA Ramm, Simone Immler, SP Flaherty, SP Flaherty, T Pizzari, Tim R. Birkhead, Tom Pizzari, TT Smith, WD Hamilton, WG Breed, WG Breed, William G. Breed   +40 more
core   +7 more sources

Sperm thermotaxis [PDF]

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
openaire   +3 more sources

Cryopreservation of single-sperm: where are we today?

Reproductive Biology and Endocrinology, 2020
Background Patients with severe oligospermia and nonobstructive azoospermia have very limited numbers of viable sperm in their epididymal and testicular samples. Thus, cryopreservation of their sperm is performed to avoid repeated sperm retrievals and to
Shasha Liu, Fuping Li
doaj   +1 more source

Sperm DNA fragmentation testing: Summary evidence and clinical practice recommendations

Andrologia, 2020
We herein summarise the evidence concerning the impact of sperm DNA fragmentation in various clinical infertility scenarios and the advances on sperm DNA fragmentation tests. The collected evidence was used to formulate 41 recommendations.
S. Esteves, A. Zini, R. Coward, D. Evenson, J. Gosálvez, S. Lewis, R. Sharma, P. Humaidan   +7 more
semanticscholar   +1 more source

Sperm-Hybrid Micromotor for Targeted Drug Delivery. [PDF]

ACS Nano, 2017
A sperm-driven micromotor is presented as a targeted drug delivery system, which is appealing to potentially treat diseases in the female reproductive tract.
Haifeng Xu, M. Medina‐Sánchez, V. Magdanz, Lukas Schwarz, Franziska Hebenstreit, O. Schmidt   +5 more
semanticscholar   +1 more source