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bioRxiv · 10.1101/2025.07.03.663031

An ancient X chromosomal region harbours three genes potentially controlling sex determination in Cannabis sativa

Toscani, M.·Riera-Begue, A.·Malik, A.·Dowling, C.·Schilling, S.·Melzer, R.
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Abstract

O_LISex determination mechanisms in dioecious plants remain poorly understood yet offer an excellent model system to study genetic changes underlying morphological evolution. C_LIO_LIWe investigated the genetic basis of sex determination in Cannabis sativa, combining QTL mapping in a segregating population, comparative transcriptomics between monoecious and dioecious cultivars, and a genomic analysis of X-Y chromosome divergence. C_LIO_LIQTL mapping identified Monoecy1, a locus on the X chromosome putatively controlling the monoecy-dioecy trait. This locus resides in the most ancient and diverged region of the sex chromosomes and contains three genes within 60,000 bp (CsREM16, lncREM16, and CsKAN4) with distinct sex-specific and monoecy-specific expression patterns. C_LIO_LIMonoecy1 harbours genes for male-female as well as monoecious-dioecious sex determination. We propose that the combinatorial interaction of CSREM16, lncREM16 and CsKAN4 provides a unifying genetic framework for understanding male-female and monoecious-dioecious sex determination in Cannabis sativa. C_LI

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Toscani, M., Riera-Begue, A., Malik, A., Dowling, C., Schilling, S., Melzer, R.. 2025-07-03. An ancient X chromosomal region harbours three genes potentially controlling sex determination in Cannabis sativa. https://doi.org/10.1101/2025.07.03.663031

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