Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Sex discrimination in parasitoid wasps

16.06.2005


Dutch researcher Joke van Vugt investigated extremely selfish chromosomes which ensure only male offspring in two species of parasitoid wasps. She discovered that the discriminating chromosomes in the two species are not genetically similar, even though they have exactly the same effect.



Parasitoid wasps are haplodiploid. This means that the male wasps develop from unfertilised eggs and only have one set of chromosomes, namely those of their mother. Female wasps develop from fertilised eggs and have two sets of chromosomes: one from their mother and one from their father.

A special egoistic B chromosome is present in some males of the parasitoid wasp species Trichogramma kaykai and Nasonia vitripennis. Although this chromosome has the same effect and a similar structure in both wasps, Van Vugt demonstrated that both chromosomes do not share any DNA sequence homology. From this she concluded that both types of the chromosome have a different origin. Therefore the existence of more such B chromosomes in other insect species seems likely. This could also point to a simple molecular mechanism of these chromosomes which has developed more than once during the course of evolution.


More males due to selfish chromosome

The B chromosome ensures that only male offspring develop. In eggs fertilised with sperm from these males, the complete genome from the father is destroyed during the first nuclear division. However, the B chromosome remains intact and is incorporated into the chromosome set of the mother. Such fertilised eggs develop into males with the B chromosome. Accordingly this chromosome is only inherited from father to son.

This selfish chromosome is called the Paternal Sex Ratio (PSR) chromosome and was first discovered in N. vitripennis. At the end of 1997 a second PSR chromosome was discovered in the unrelated parasitoid wasp T. kaykai. This made a comparative study of PSR chromosomes possible.

PSR chromosomes can easily cross species boundaries and might therefore be useful for the control of insect pests, such as the Argentine ant. The introduction of these chromosomes would lead to increasingly less females developing. And without females such insect populations quickly perish.

Dr Joke J.F.A. van Vugt | alfa
Further information:
http://www.nwo.nl/nwohome.nsf/pages/NWOP_6CVFCV_Eng

More articles from Life Sciences:

nachricht A Map of the Cell’s Power Station
18.08.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

nachricht On the way to developing a new active ingredient against chronic infections
18.08.2017 | Deutsches Zentrum für Infektionsforschung

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

A Map of the Cell’s Power Station

18.08.2017 | Life Sciences

Engineering team images tiny quasicrystals as they form

18.08.2017 | Physics and Astronomy

Researchers printed graphene-like materials with inkjet

18.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>