idw – Informationsdienst Wissenschaft

Nachrichten, Termine, Experten

Grafik: idw-Logo
Science Video Project
idw-Abo

idw-News App:

AppStore

Google Play Store



Instance:
Share on: 
10/12/2017 13:54

No sex, no problem!

Romas Bielke Öffentlichkeitsarbeit
Georg-August-Universität Göttingen

    Sexual reproduction is linked to various benefits for the survival of a species. Amongst others, sex counters the accumulation of accidentally occurring deleterious mutations by allowing for exchange of genetic material. According to the scientific consensus, loss of sex in favour of clonal reproduction leads to a stepwise accumulation of deleterious mutations, which eventually causes extinction of a species. Now scientists of the Universities of Göttingen and Lausanne found out, that ancient asexual oribatid mites are more effective in purging deleterious mutations as compared to their sexual relatives. The results are reported in the current issue of Nature Communications.

    Pressemitteilung
    Nr. 200/2017

    No sex, no problem!
    Biologists from Goettingen analyse how loss of sex affects the genetic makeup of oribatid mites

    (pug) Sexual reproduction is linked to various benefits for the survival of a species. Amongst others, sex counters the accumulation of accidentally occurring deleterious mutations by allowing for exchange of genetic material. According to the scientific consensus, loss of sex in favour of clonal reproduction leads to a stepwise accumulation of deleterious mutations, which eventually causes extinction of a species. Now scientists of the Universities of Göttingen and Lausanne found out, that ancient asexual oribatid mites are more effective in purging deleterious mutations as compared to their sexual relatives. The results are reported in the current issue of Nature Communications.

    “Up to now, experimental evidence is scarce and restricted to species that lost sex in recent times”, says Alexander Brandt, first author of the study, who works in the animal ecology group at the Johann-Friedrich-Blumenbach Institute of Zoology and Anthropology of Göttingen University. To unravel the consequences of loss of sex in the long term, the scientists have sequenced and analysed the genetic makeup of various sexual and ancient asexual oribatid mites. The findings are surprising: ancient asexual oribatid mites are more effective in purging deleterious mutations as compared to their sexual relatives.

    “Oribatid mites are well suited for analysing the long-term consequences of asexual reproduction, as within this animal group, sex was lost millions of years ago several times independently”, explains Dr. Jens Bast, research fellow at the University of Lausanne and senior author of the study. “The discovery of asexual oribatid mites purging deleterious mutations more effectively as compared to their sexual relatives indicates the existence of a certain peculiarity in oribatid mites which enables them to survive without sex in evolutionary time scales”, adds Brandt.

    So far, scientists can only speculate about the nature of the peculiarity: the population sizes of oribatid mites may play a role. The number of animals that make a population has, just like mixing up the genomic makeup, a strong influence on how effective natural selection counters the accumulation of deleterious mutations. The fact that populations of asexual oribatid mites are on average substantially larger as compared to sexual species indicates that the observed effective natural selection might indeed be due to their especially large populations. This allowed at least some species of oribatid mites to survive without sex for millions of years.

    Original Publication: Brandt et al., Effective purifying selection in ancient asexual oribatid mites, Nature Communications 2017
    doi: 10.1038/s41467-017-01002-8

    Contact:
    Alexander Brandt
    University of Göttingen
    Johann-Friedrich-Blumenbach Institute of Zoology and Anthropology
    Untere Karspüle 2, 37073 Göttingen
    Telefon (0551) 39-26041
    E-Mail: abrandt3@gwdg.de
    Internet: www.uni-goettingen.de


    Images

    The asexual oribatid mite species Nothrus palustris (Figure 1) and a distantly related sexual species Steganacarus magnus (Figure 2) on litter particles. Both species measure about 0.9 mm in length.
    The asexual oribatid mite species Nothrus palustris (Figure 1) and a distantly related sexual specie ...
    Copyright: Dr. Sarah Zieger
    None

    The asexual oribatid mite species Nothrus palustris (Figure 1) and a distantly related sexual species Steganacarus magnus (Figure 2) on litter particles. Both species measure about 0.9 mm in length.
    The asexual oribatid mite species Nothrus palustris (Figure 1) and a distantly related sexual specie ...
    Copyright: Dr. Sarah Zieger
    None


    Criteria of this press release:
    Journalists
    Biology
    transregional, national
    Research results
    English


     

    The asexual oribatid mite species Nothrus palustris (Figure 1) and a distantly related sexual species Steganacarus magnus (Figure 2) on litter particles. Both species measure about 0.9 mm in length.


    For download

    x

    The asexual oribatid mite species Nothrus palustris (Figure 1) and a distantly related sexual species Steganacarus magnus (Figure 2) on litter particles. Both species measure about 0.9 mm in length.


    For download

    x

    Help

    Search / advanced search of the idw archives
    Combination of search terms

    You can combine search terms with and, or and/or not, e.g. Philo not logy.

    Brackets

    You can use brackets to separate combinations from each other, e.g. (Philo not logy) or (Psycho and logy).

    Phrases

    Coherent groups of words will be located as complete phrases if you put them into quotation marks, e.g. “Federal Republic of Germany”.

    Selection criteria

    You can also use the advanced search without entering search terms. It will then follow the criteria you have selected (e.g. country or subject area).

    If you have not selected any criteria in a given category, the entire category will be searched (e.g. all subject areas or all countries).