The DSM diagnostic criteria for gender identity disorder in adolescents and adults.

Apart from some general issues related to the Gender Identity Disorder (GID) diagnosis, such as whether it should stay in the DSM-V or not, a number of problems specifically relate to the current criteria of the GID diagnosis for adolescents and adults. These problems concern the confusion caused by similarities and differences of the terms transsexualism and GID, the inability of the current criteria to capture the whole spectrum of gender variance phenomena, the potential risk of unnecessary physically invasive examinations to rule out intersex conditions (disorders of sex development), the necessity of the D criterion (distress and impairment), and the fact that the diagnosis still applies to those who already had hormonal and surgical treatment. If the diagnosis should not be deleted from the DSM, most of the criticism could be addressed in the DSM-V if the diagnosis would be renamed, the criteria would be adjusted in wording, and made more stringent. However, this would imply that the diagnosis would still be dichotomous and similar to earlier DSM versions. Another option is to follow a more dimensional approach, allowing for different degrees of gender dysphoria depending on the number of indicators. Considering the strong resistance against sexuality related specifiers, and the relative difficulty assessing sexual orientation in individuals pursuing hormonal and surgical interventions to change physical sex characteristics, it should be investigated whether other potentially relevant specifiers (e.g., onset age) are more appropriate.

Transgenic zebrafish with fluorescent germ cell: a useful tool to visualize germ cell proliferation and juvenile hermaphroditism in vivo.

Juvenile zebrafish are hermaphroditic; undifferentiated gonads first develop into ovary-like tissues, which then either become ovaries and produce oocytes (female) or degenerate and develop into testes (male). In order to fully capture the dynamic processes of germ cells' proliferation and juvenile hermaphroditism in zebrafish, we established transgenic lines TG(beta-actin:EGFP), harboring an enhanced green fluorescent protein (EGFP) gene driven by a medaka beta-actin promoter. In TG(beta-actin:EGFP), proliferating germ cells and female gonads strongly expressed EGFP, but fluorescence was only dimly detected in male gonads. Based on the fluorescent (+) or nonfluorescent (-) appearance of germ cells seen in living animals, three distinct groups were evident among TG(beta-actin:EGFP). Transgenics in ++ group (44%) were females, had fluorescent germ cells as juveniles, and female gonads continuously fluoresced throughout sexual maturation. Transgenics in +- (23%) and -- (33%) groups were males. Fluorescent germ cells were transiently detected in +- transgenics from 14 to 34 days postfertilization (dpf), but were not detected in -- transgenics throughout their life span. Histological analyses showed that 26-dpf-old transgenics in ++, +-, and -- groups all developed ovary-like tissues: Germ cells in -- group juveniles arrested at the gonocyte stage and accumulated low quantities of EGFP, while those in ++ group juveniles highly proliferated into diplotene to perinucleolar stages and accumulated high quantities of EGFP. In +- group juveniles, degenerating oocytes, gonocytes, and spermatogonia were coexistent in transiently fluorescent gonads. Therefore, the fluorescent appearance of gonads in this study was synchronous with the differentiation of ovary-like tissues. Thus, TG(beta-actin:EGFP) can be used to visualize germ cells' proliferation and juvenile hermaphroditism in living zebrafish for the first time.