Genetic variation and temperature affects hybrid barriers during interspecific hybridization. (12th October 2019)

• Record Type: Journal Article
• Authors: Bjerkan, Katrine N.; Hornslien, Karina S.; Johannessen, Ida M.; Krabberød, Anders K.; van Ekelenburg, Yuri S.; Kalantarian, Maryam; Shirzadi, Reza; Comai, Luca; Brysting, Anne K.; Bramsiepe, Jonathan; Grini, Paul E.
• Is Part Of: Plant journal. Volume 101:Number 1(2020)
• Page Start: 122
• Page End: 140
• Publication Date: 2019-10-12
• Subjects: Imprinting -- endosperm -- hybridization -- post‐zygotic barriers -- Arabidopsis thaliana -- Arabidopsis arenosa -- Arabidopsis lyrata; Plant molecular biology -- Periodicals; Plant cells and tissues -- Periodicals; Botany -- Periodicals; 580
• DOI: 10.1111/tpj.14523
• Languages: English
• ISSNs: 0960-7412

Abstract

Summary: Genomic imprinting regulates parent‐specific transcript dosage during seed development and is mainly confined to the endosperm. Elucidation of the function of many imprinted genes has been hampered by the lack of corresponding mutant phenotypes, and the role of imprinting is mainly associated with genome dosage regulation or allocation of resources. Disruption of imprinted genes has also been suggested to mediate endosperm‐based post‐zygotic hybrid barriers depending on genetic variation and gene dosage. Here, we have analyzed the conservation of a clade from the MADS‐box type I class transcription factors in the closely related species Arabidopsis arenosa, A . lyrata, and A . thaliana, and show that AGL36‐like genes are imprinted and maternally expressed in seeds of Arabidopsis species and in hybrid seeds between outbreeding species. In hybridizations between outbreeding and inbreeding species the paternally silenced allele of the AGL36‐like gene is reactivated in the hybrid, demonstrating that also maternally expressed imprinted genes are perturbed during hybridization and that such effects on imprinted genes are specific to the species combination. Furthermore, we also demonstrate a quantitative effect of genetic diversity and temperature on the strength of the post‐zygotic hybridization barrier. Markedly, a small decrease in temperature during seed development increases the survival of hybrid F1 seeds, suggesting that abiotic and genetic parameters play important roles in post‐zygotic species barriers, pointing at evolutionary scenarios favoring such effects. Open Research Badges: This article has earned an Open Data Badge for making publicly available the digitally‐shareable data necessary to reproduce the reported results. The data is available at https://www.ncbi.nlm.nih.gov/bioproject/?term=PRJNA562212 . All sequences generated in this study have been deposited in the National Center for Biotechnology Information Sequence Read Archive (https://www.ncbi.nlm.nih.gov/sra/ ) with project number PRJNA562212. Significance Statement: We have investigated the hypothesis that imprinted genes mediate reproductive barriers between species in the context of genetic and environmental variance, and demonstrate that perturbation of imprinted genes, genetic diversity as well as environmental factors act in concert to define the strength of endosperm‐based Arabidopsis hybridization barriers.