{Reference Type}: Journal Article
{Title}: Genetic sex determination in three closely related hydrothermal vent gastropods, including one species with intersex individuals.
{Author}: Castel J;Pradillon F;Cueff V;Leger G;Daguin-Thiébaut C;Ruault S;Mary J;Hourdez S;Jollivet D;Broquet T;
{Journal}: J Evol Biol
{Volume}: 37
{Issue}: 7
{Year}: 2024 Jul 10
{Factor}: 2.516
{DOI}: 10.1093/jeb/voae051
{Abstract}: Molluscs have undergone many transitions between separate sexes and hermaphroditism, which is of interest in studying the evolution of sex determination and differentiation. Here, we combined multi-locus genotypes obtained from restriction site-associated DNA (RAD) sequencing with anatomical observations of the gonads of three deep-sea hydrothermal vent gastropods of the genus Alviniconcha living in the southwest Pacific. We found that all three species (Alviniconcha boucheti, Alviniconcha strummeri, and Alviniconcha kojimai) share the same male-heterogametic XY sex-determination system but that the gonads of XX A. kojimai individuals are invaded by a variable proportion of male reproductive tissue. The identification of Y-specific RAD loci (found only in A. boucheti) and the phylogenetic analysis of three sex-linked loci shared by all species suggested that X-Y recombination has evolved differently within each species. This situation of three species showing variation in gonadal development around a common sex-determination system provides new insights into the reproductive mode of poorly known deep-sea species and opens up an opportunity to study the evolution of recombination suppression on sex chromosomes and its association with mixed or transitory sexual systems.