ESPE Abstracts

Background: Individuals with a mixed 46,XX and XY karyotype, categorized as ovotesticular disorder of sexual development (ODSD), have gonads with either an ovary in one side and a testis in the other side or an ovotestis.

Objective and hypotheses: This study aimed to investigate the relationship between sex chromosomes and testicular and ovarian cell types in gonadal tissues associated with ODSD patients with 46,XX/46,XY.

Method: Gonadal tissues from three ODSD patients with a 46,XX/46,XY karyotype were examined for histopathological features, fluorescent in situ hybridization (FISH) for X and Y chromosomes, and immunohistochemistry for SOX9 as a Sertoli cell marker and FOXL2 as an ovarian follicular epithelial marker.

Results: The histological features of the gonadal tissues of three patients showed an ovotestis, a testis and an ovary on each side, and a testicular tissue only, respectively. FISH analysis of the ovotestis demonstrated that cells with XX signals were involved within the Sertoli cells in seminiferous tubules, while cells having Y signals were observed within the epithelia of ovarian follicles. Likewise, the involvement of cells with opposite sex chromosomes was seen in the gonads of the other two patients. The expression of SOX9 was seen only in the seminiferous tubules and that of FOXL2 was observed only in the ovarian follicles, despite the involvement of opposite sex chromosomes.

Conclusion: We suggest that the destiny of individual gonadal epithelial cells is influenced by local environmental factors rather than by the sex chromosome type.

Funding: This work was supported by New Zealand and Japan Partnership Strategy, Japan Society for the Promotion of Science, and Grant-in-Aid for Scientific Research from the Ministry of Education, Culture, Sports, Science, and Technology of Japan (25460427).