<p> <taxon tax_id="37657">Silene latifolia</taxon> (White campion) and <taxon tax_id="39879">Silene dioica</taxon> (Red campion) are plants with separate sexes and with X and Y sex chromosomes. The presence or absence of the Y chromosome determines which sex organs will develop. Y4 is a Y-linked gene that has a homologue on the X chromosome, X4. Both Y4 and X4 are expressed and potentially encode enzymes related to phosphoglycerate mutase and fructose-2,6-bisphosphatase [<cite idref="PUB00027903"/>]. This group also includes sequences from plants that do not have separate sexes, such as Arabidopsis and other species of Silene, thus providing examples for comparison of substitution rates in the X- and Y-linked genes of plants [<cite idref="PUB00027980"/>].</p> Uncharacterised conserved protein UCP036920, phosphoglycerate mutase, plant X4/Y4