Navigation Links
Primate sperm competition: speed matters

Researchers at UC San Diego and UC Irvine have found evidence that supports the theory that reproductive competition during the evolution of primate species has occurred at the level of sperm cell motility. In a paper published online by the Journal of the Royal Society Interface, a team led by Michael Berns, an adjunct professor of bioengineering at UCSD and a professor of biomedical engineering at the Beckman Laser Institute at UC Irvine, and UCSD Ph.D. candidate Jaclyn Nascimento reported that sperm cells from the more promiscuous chimpanzee and rhesus macaque species swim much faster and with much greater force than those of humans and gorillas, species where individual females mate primarily with only one male during a reproductive cycle.

Female chimps and macaques typically mate with several males in a social group, so that a male with faster and stronger swimming sperm cells would in theory be more likely to successfully fertilize an egg.

Rapidly swimming sperm cells would be evolutionarily favored when the mating pattern is polygamous and that is consistent with our measurements of chimp and rhesus macaque sperm, said Nascimento.

The research team found significantly lower swimming forces and slower swimming speeds with human sperm, and the slowest of all belonged to gorillas. Dominant silverbacks are known to effectively discourage other males from mating with the females in their harems, so faster sperm wouldnt seem to be an advantage to them, Nascimento said.

However the researchers were surprised that the speed and force of human sperm fell in between the gorillas and the chimps. Maybe humans havent always been as monogamous as we had thought, Berns said.

Beginning more than 35 years ago, scientists began using laser beams to trap individual atoms, microscopic particles, DNA molecules, and various cells. Berns has been a pioneer in the design of laser tweezers, which rely on the momentum inherent in laser light: when the path of laser light bends as it passes through a small transparent object such as a cell, some of the lights momentum is transferred to the cell, effectively holding, or trapping it. The brighter the laser, the more firmly the cell is held.

After attending a talk at the Center for Reproduction of Endangered Species (CRES) at the San Diego Zoo about the theory that faster sperm could have an advantage in the reproductive success of polygamous primates, Berns modified his laser tweezers so that after a cell was trapped, the light intensity could be reduced in a precise manner. Such a timed decay in laser brightness allows a trapped sperm cell to escape at the point at which its swimming force exceeds the trapping force. The adjustable laser tweezers and sperm-tracking software allowed the team led by Berns and Nascimento to precisely and accurately measure swimming force and speed of hundreds of individual sperm cells from males of the four primate species.

While biologists have been interested in this sperm competition question for years, it required the collaboration of biologists, physicists and engineers to design the right equipment to test the theory, said Berns.


Contact: Rex Graham
University of California - San Diego

Related biology news :

1. Transplantation Of Monkey Embryonic Stem Cells Reverses Parkinson Disease In Primates
2. Primates on the brink
3. Scientists track stealth DNA elements in primate evolution
4. Ethical guidelines suggested for research that would put human stem cells in primates
5. Primate virus jumps species barrier to humans for first time in Asia
6. Ancient DNA confirms single origin of Malagasy primates
7. Primates harvest bee nests in Ugandan reserve
8. Diabetes researchers pioneer islet cell xenotransplantation in primate studies
9. Experimental vaccine protects nonhuman primates when given after exposure to Marburg virus
10. Gene-specific Ebola therapies protect non-human primates from lethal disease
11. Ancient global warming drove early primates dispersal
Post Your Comments:
(Date:4/26/2016)... India and LONDON ... Infosys Finacle, part of EdgeVerve Systems, a product ... and Onegini today announced a partnership to integrate ... solutions.      (Logo: ... to provide their customers enhanced security to access ...
(Date:4/15/2016)...  A new partnership announced today will help ... in a fraction of the time it takes ... life insurance policies to consumers without requiring inconvenient ... Diagnostics, rapid testing (A1C, Cotinine and HIV) and ... weight, pulse, BMI, and activity data) available at ...
(Date:4/13/2016)... April 13, 2016  IMPOWER physicians supporting Medicaid patients ... a new clinical standard in telehealth thanks to a ... the higi platform, IMPOWER patients can routinely track key ... body mass index, and, when they opt in, share ... visit to a local retail location at no cost. ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... ... June 23, 2016 , ... Charm Sciences, Inc. is ... has received AOAC Research Institute approval 061601. , “This is another AOAC-RI approval ... Bob Salter, Vice President of Regulatory and Industrial Affairs. “The Peel Plate methods ...
(Date:6/23/2016)... --  EpiBiome , a precision microbiome engineering company, today ... from Silicon Valley Bank (SVB). The financing will allow ... drug development efforts, as well as purchase additional lab ... been an incredible strategic partner to us – one ... provide," said Dr. Aeron Tynes Hammack , EpiBiome,s ...
(Date:6/23/2016)... ... ... In a new case report published today in STEM CELLS Translational Medicine, ... after being treated for breast cancer benefitted from an injection of stem cells derived ... debilitating, frequent side effect of cancer treatment. , Lymphedema refers to the ...
(Date:6/23/2016)... LONDON , June 23, 2016 ... & Hematology Review, 2016;12(1):22-8 ... Review , the peer-reviewed journal from touchONCOLOGY, ... the escalating cost of cancer care is placing ... a result of expensive biologic therapies. With the ...
Breaking Biology Technology: