Related Experiment Video
Updated: Mar 6, 2026
08:08
Determination of Self- and Inter-incompatibility Relationships in Apricot Combining Hand-Pollination, Microscopy and Genetic Analyses
Published on: June 16, 2020
7.9K
Hybrid incompatibility caused by an epiallele
Todd Blevins1,2, Jing Wang2, David Pflieger3
1Howard Hughes Medical Institute, Indiana University, Bloomington, IN 47405; todd.blevins@ibmp-cnrs.unistra.fr cpikaard@indiana.edu.
Summary
Hybrid incompatibility, a key step in speciation, can be caused by a silent epiallele of the HISN6B gene. This epigenetic silencing can be reversed by mutating specific genes, allowing hybrid survival.
Area of Science:
- Genetics
- Epigenetics
- Plant Biology
Background:
- Hybrid incompatibility contributes to reproductive isolation and speciation.
- Epigenetic variations can influence gene flow between populations.
Purpose of the Study:
- To investigate the role of a silent epiallele in hybrid incompatibility.
- To explore the epigenetic basis of hybrid lethality in Arabidopsis thaliana.
Main Methods:
- Comparative analysis of HISN6 gene copies in Arabidopsis thaliana accessions Cvi-0 and Col-0.
- Genetic manipulation of histone deacetylase and DNA methyltransferase genes (HDA6, MET1, CMT3).
- Assessment of hybrid progeny survival and gene expression.
Main Results:
- A silent epiallele of HISN6B in Col-0 causes lethality in Cvi-0 × Col-0 hybrids when combined with Cvi-0 HISN6A.
- Mutations in HDA6, MET1, or CMT3 reactivate the silenced HISN6B, rescuing hybrid lethality.
- HISN6-dependent hybrid lethality is an epigenetically reversible phenomenon.
Conclusions:
- Epigenetic variation, specifically silent epialleles, can drive hybrid incompatibility and speciation.
- Reversible epigenetic mechanisms can limit gene flow between diverging populations.
- Targeting epigenetic regulators offers a potential strategy to overcome reproductive barriers.
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