YY males of the dioecious plant Mercurialis annua are fully viable but produce largely infertile pollen
The suppression of recombination during sex‐chromosome evolution is thought to be favoured by linkage between the sex‐determining locus and sexually antagonistic loci, and leads to the degeneration of the chromosome restricted to the heterogametic sex. Despite substantial evidence for genetic degeneration at the sequence level, the phenotypic effects of the earliest stages of sex‐chromosome evolution are poorly known.
Here, we compare the morphology, viability and fertility between XY and YY individuals produced by crossing seed‐producing males in the dioecious plant
Mercurialis annua
, which has young sex chromosomes with limited X−Y sequence divergence.
We found no significant difference in viability or vegetative morphology between XY and YY males. However, electron microscopy revealed clear differences in pollen anatomy, and YY males were significantly poorer sires in competition with their XY counterparts. Our study suggests either that the X chromosome is required for full male fertility in
M. annua
, or that male fertility is sensitive to the dosage of relevant Y‐linked genes.
We discuss the possibility that the maintenance of male‐fertility genes on the X chromosome might have been favoured in recent population expansions that selected for the ability of females to produce pollen in the absence of males.
No keywords indexed for this article. Browse by subject →
Douglas Bates, Martin Mächler, Ben Bolker et al.
D Charlesworth, B Charlesworth, M T Morgan
Showing 50 of 104 references
J. F. Gerchen, P. Veltsos · 2022
Paris Veltsos, Kate E Ridout · 2019
- Published
- Jul 25, 2019
- Vol/Issue
- 224(3)
- Pages
- 1394-1404
- License
- View
You May Also Like
Nate McDowell, William T. Pockman · 2008
3,684 citations
T. P. McGONIGLE, M. H. MILLER · 1990
3,111 citations
Hendrik Poorter, KARL J. NIKLAS · 2011
2,553 citations
Ian J. Wright, Peter B. Reich · 2005
2,502 citations