bioRxiv Science⌕ Search

Biology subjects

Boewer, F.

Publications and source records attributed to Boewer, F..

3 recordsLinked to original sources

Transcriptional control of meiotic recombination by the DREAM complex

Meiotic chromosome segregation and recombination, essential for sexual reproduction and evolution, require a specialized gene set. However, how meiotic gene expression is controlled remains largely unclear in multicellular eukaryotes. Here, we identify the DREAM complex as a transcriptional regulator of meiotic recombination in Arabidopsis. We show that the DREAM complex localizes to meiotic chromosomes, and that reduced DREAM function disrupts recombination and causes sterility. Meiocyte-specific transcriptomics combined with genome-wide binding analyses revealed that recombination genes, including the crossover-promoting helicase MER3, are direct DREAM targets. Notably, bypassing DREAM regulation of MER3 partially restores recombination in DREAM-deficient plants. Our findings establish the DREAM complex as a major meiotic regulator. Given that reduced DREAM function causes reproductive defects in species such as Drosophila and mice, this role may be conserved across multicellular eukaryotes.

cell biology↗

The two plant-specific DREAM components FLIC and FLAC repress floral transition in Arabidopsis

The DREAM complex is a key transcriptional regulator especially involved in the control of the cell cycle and development. Here, we characterise two novel plant- specific DREAM components, FLIC and FLAC, which we identified through tandem affinity purification experiments as interactors of conserved core DREAM constituents. We demonstrate that plants lacking both FLIC and FLAC exhibit pleiotropic phenotypes, including stunted growth and reduced fertility. Notably, flic flac double mutants show an early-flowering phenotype, an aspect that we found to be shared with mutants of the core DREAM component LIN37, with which FLIC and FLAC interact in binary protein-protein interaction assays. Performing reverse affinity purification experiments, we detected the JMJ14/NAC050/NAC052 module, known for its involvement in flowering repression, in the interactome of both FLIC and FLAC. Subsequent binary interaction studies then link the JMJ14/NAC050/NAC052 module via LIN37 to the DREAM complex providing a mechanistic framework on how flowering time could be transcriptionally controlled by the DREAM complex. Summary blurbThis study identifies two plant-specific members of the DREAM complex, explores their roles by mutant analysis and protein interaction investigation, and links them and additional DREAM complex components to the regulation of floral transition.

developmental biology↗

SWITCH 1/DYAD is a novel WINGS APART-LIKE antagonist that maintains sister chromatid cohesion in meiosis

Mitosis and meiosis both rely on cohesin, which embraces the sister chromatids and plays a crucial role for the faithful distribution of chromosomes to daughter cells. Prior to the cleavage by Separase at anaphase onset, cohesin is largely removed from chromosomes by the non-proteolytic action of WINGS APART-LIKE (WAPL), a mechanism referred to as the prophase pathway. To prevent the premature loss of sister chromatid cohesion, WAPL is inhibited in early mitosis by Sororin. However, Sororin homologs have only been found to function as WAPL inhibitors during mitosis in vertebrates and Drosophila. Here we show that SWITCH 1/DYAD defines a novel WAPL antagonist that acts in meiosis of Arabidopsis. Crucially, SWI1 becomes dispensable for sister chromatid cohesion in the absence of WAPL. Despite the lack of any sequence similarities, we found that SWI1 is regulated and functions in a similar manner as Sororin hence likely representing a case of convergent molecular evolution across the eukaryotic kingdom.

cell biology↗