In many dioecious species, doublesex/male-abnormal-3 (DM) domain genes have critical roles in sex-specific development and function.
To examine whether such sex-specific functions may also function in simultaneous hermaphrodites, we investigated the role of DM domain genes in the planarian, Schmidtea mediterranea.
dmd-1 has a male-specific role in the maintenance and regeneration of the testes and male accessory reproductive organs.In addition, dmd-1 has a male-specific role in the maintenance and regeneration of the testes and male accessory reproductive organs.These results demonstrate that dmd-1 is an essential component of pathways responsible for inductive specification of the germline and development of a sex-specific somatic gonadal niche in a simultaneous hermaphrodite.In the meantime, to ensure continued support, we are displaying the site without styles and Java Script.Evolutionary transitions between hermaphroditic and dioecious reproductive states are found in many groups of animals.We also show that a homologue of dmd-1 exhibits sex-specific expression in S.mansoni, a derived, dioecious flatworm, suggesting a means by which modulation of sex-specific pathways may drive the transition from hermaphroditism to dioecy.1d), and are found in the developing testes in sexually immature planarians (Fig. Similarly, in the asexual strain, we detected dmd-1-expressing cells in the germ cell clusters along the dorsolateral region of the animal (Fig. We also used transmission electron microscopy (TEM) to visualize the dorsolateral germ cell clusters in asexual planarians.Within these germ cell clusters, we found somatic cells with processes surrounding the germ cells.In contrast to dioecious organisms, simultaneous hermaphrodites produce gametes and accessory reproductive organs of both sexes.In spite of all that has been learned about sex determination mechanisms in dioecious animals, little is known about how simultaneous hermaphrodites with no sex chromosomes specify and maintain the fates of male and female germ cells as well as sexually dimorphic somatic structures in the same body.