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PIWIs, piRNAs and Retrotransposons: Complex battles during reprogramming in gametes and early embryos
S J Russell1, L Stalker1, J LaMarre1
1Department of Biomedical Sciences, University of Guelph, Guelph, ON, Canada.
Reproduction in Domestic Animals = Zuchthygiene
|October 21, 2017
Summary
Reproductive cells reprogram to become pluripotent, but this can activate transposable elements (TEs). The PIWI pathway, a key TE suppressor, is vital for fertility and gene regulation in reproduction.
Area of Science:
- Reproductive biology
- Epigenetics
- Genomics
Background:
- Gamete and embryo development require cellular reprogramming for pluripotency.
- Reprogramming involves epigenetic changes like histone and DNA methylation.
- Epigenetic remodeling can release constraints on transposable element (TE) expression.
Purpose of the Study:
- To review the mechanisms controlling transposable elements during reproduction.
- To highlight the role of the PIWI pathway in suppressing TEs.
- To discuss the implications for fertility and gene regulation.
Main Methods:
- Literature review focusing on transposable element control.
- Analysis of epigenetic reprogramming in gametes and embryos.
- Examination of the PIWI pathway's function and conservation.
Main Results:
- Uncontrolled TE expression during reprogramming can cause infertility.
- Organisms possess potent mechanisms to suppress TE activity.
- The PIWI pathway is a conserved, small RNA-guided system crucial for TE suppression.
Conclusions:
- TE suppression is essential for maintaining fertility during reproductive processes.
- The PIWI pathway plays a critical role in safeguarding the genome from TEs.
- This pathway may have broader roles in gene regulation in reproductive and other cellular contexts.
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