In the giant wood spider Nephila pilipes, a highly sexually dimorphic and polygamous species, many small males compete with one other for access to a few huge females. During copulation these males are known to sever their own genitals in an attempt to plug the female, thereby gaining paternity advantage by preventing other males from mating with her.
Until recently however, nothing has been known about the origin and function of additional and very solid plugs researchers have observed that also commonly cover female genitals in this species. Now biologists have discovered the origin of this additional other plugging mechanism.
The international team of scientists who published their findings in the July 19 issue of the journal PLoS ONE, consists of Matjaž Kuntner, research associate at the Smithsonian's National Museum of Natural History and chair of the Institute of Biology at the Scientific Research Centre, Slovenian Academy of Sciences and Arts; Daiqin Li, associate professor at the Department of Biological Sciences, National University of Singapore, and doctoral students Matjaž Gregoriè and Shichang Zhang, and postdoc Simona Kralj-Fišer.
Before the trials the researchers speculated that the additional mystery plugs commonly found covering female genitals might be produced by the copulating male, or the female, or perhaps both spider sexes. The researchers tested these possibilities by staging laboratory mating trials with varying degrees of females mating with multiple males. They observed that no plugs were ever formed during mating trials, but instead, females exposed to many males produced the amorphous plugs during the egg-laying process.
These plugs, when hardened, prevented subsequent copulation. The authors conclude that the newly discovered "self-plugging" mechanism represents a female adaptation to sexual conflict through the prevention of unwanted and excessive copulations.
John Gibbons | EurekAlert!
Antimicrobial substances identified in Komodo dragon blood
23.02.2017 | American Chemical Society
New Mechanisms of Gene Inactivation may prevent Aging and Cancer
23.02.2017 | Leibniz-Institut für Alternsforschung - Fritz-Lipmann-Institut e.V. (FLI)
Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...
The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.
The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...
Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...
Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".
Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...
13.02.2017 | Event News
10.02.2017 | Event News
09.02.2017 | Event News
23.02.2017 | Physics and Astronomy
23.02.2017 | Earth Sciences
23.02.2017 | Life Sciences