YY males of the dioecious plant Mercurialis annua are fully viable but produce largely infertile pollen

• DOI: 10.1111/nph.16016
• Publication Date: 2019-06-23T02:00:41Z
• Authors: Xinji Li; Paris Veltsos; Guillaume G. Cossard; Jörn Gerchen; John R. Pannell
• Keywords: Heterogametic sex

The suppression of recombination during sex-chromosome evolution is thought to be favoured by linkage between the sex-determining locus and sexually antagonistic loci, leads degeneration chromosome restricted heterogametic sex. Despite substantial evidence for genetic at sequence level, phenotypic effects earliest stages are poorly known. Here, we compare morphology, viability fertility XY YY individuals produced crossing seed-producing males in dioecious plant Mercurialis annua, which has young sex chromosomes with limited X-Y divergence. We found no significant difference or vegetative morphology males. However, electron microscopy revealed clear differences pollen anatomy, were significantly poorer sires competition their counterparts. Our study suggests either that X required full male M. sensitive dosage relevant Y-linked genes. discuss possibility maintenance male-fertility genes on might have been recent population expansions selected ability females produce absence