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Elevated Temperatures Cause Transposon-Associated DNA Damage in C. elegans Spermatocytes
Nicole A Kurhanewicz1, Devin Dinwiddie1, Zachary D Bush1
1Institute of Molecular Biology, Department of Biology, University of Oregon, 1229 Franklin Boulevard, Eugene, OR 97403, USA.
Current Biology : CB
|October 16, 2020
Summary
Elevated temperatures increase DNA breaks in male reproductive cells, reducing fertility. This is linked to mobile DNA elements called Tc1/mariner transposable elements, not SPO-11.
Area of Science:
- Reproductive Biology
- Genetics
- Molecular Biology
Background:
- Spermatogenesis is sensitive to temperature fluctuations, and male infertility is linked to heat exposure.
- Mechanisms of temperature-induced male infertility are not fully understood.
Purpose of the Study:
- To investigate the impact of temperature increases on DNA integrity during spermatogenesis.
- To elucidate the molecular mechanisms underlying heat-induced male infertility.
Main Methods:
- Exposure of Caenorhabditis elegans to a 2°C temperature increase.
- Quantification of double-strand DNA breaks (DSBs) in spermatocytes.
- Analysis of Tc1/mariner transposable element mobilization.
- Identification of genomic regions affected by Tc1 insertions.
Main Results:
- A 2°C temperature increase caused a 25-fold rise in DSBs in spermatocytes during meiotic prophase I.
- Heat-induced DSBs were independent of the endonuclease SPO-11.
- DSB formation correlated with heat-induced Tc1/mariner transposable element mobilization.
- Specific genomic regions were identified for de novo Tc1 insertions.
- Oocytes showed no changes in DSB formation or transposon mobility.
Conclusions:
- Spermatocytes are intolerant to higher temperatures due to impaired repression of mobile DNA elements.
- Heat-induced Tc1 mobilization causes excessive DNA damage and genome alterations, impairing male fertility.
Keywords:
C. elegansDNA breaksDNA damageheat stressmale infertilitymeiosissexual dimorphismspermatogenesistransposonsMore Related Videos
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