Gamete expression of TALE class HD genes activates the diploid sporophyte program in Marchantia polymorpha
Abstract
Eukaryotic life cycles alternate between haploid and diploid phases and in phylogenetically diverse unicellular eukaryotes, expression of paralogous homeodomain genes in gametes primes the haploid-to-diploid transition. In the unicellular Chlorophyte alga Chlamydomonas KNOX and BELL TALE-homeodomain genes mediate this transition. We demonstrate that in the liverwort Marchantia polymorpha paternal (sperm) expression of three of five phylogenetically diverse BELL genes, MpBELL234, and maternal (egg) expression of both MpKNOX1 and MpBELL34 mediate the haploid-to-diploid transition. Loss-of-function alleles of MpKNOX1 result in zygotic arrest, whereas loss of either maternal or paternal MpBELL234 results in variable zygotic and early embryonic arrest. Expression of MpKNOX1 and MpBELL34 during diploid sporophyte development is consistent with a later role for these genes in patterning the sporophyte. These results indicate that the ancestral mechanism to activate diploid gene expression was retained in early diverging land plants and subsequently co-opted during evolution of the diploid sporophyte body.
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All data generated or analysed during this study are included in the manuscript and supporting files.
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Author details
Funding
Australian Research Council (FF0551326)
- Tom Dierschke
- Edurado Flores-Sondoval
- John L Bowman
Australian Research Council (DP130100177)
- Tom Dierschke
- Edurado Flores-Sondoval
- John L Bowman
Australian Research Council (DP170100049)
- Tom Dierschke
- Edurado Flores-Sondoval
- Madlen I Rast-Somssich
- John L Bowman
Deutsche Forschungsgemeinschaft (SFB944,P13)
- Tom Dierschke
- Felix Althoff
- Sabine Zachgo
Australian Research Council (DP210101423)
- Tom Dierschke
- John L Bowman
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
© 2021, Dierschke et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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