• The study aims to understand why some people are attracted to people of the same sex, while others are attracted to those of the opposite sex. The project studies which genes influence sexual attraction. We are currently collecting families in which there are at least 4 male members who identify as gay. Access to straight members of the same family is also important in order to compare genetic differences between gay and straight individuals within the same family. This project is being run by Drs. Eric Vilain and Tuck Ngun.

  • In humans (and in mammals in general), sex is determined when the undifferentiated and bipotential embryonic gonad (the genital ridge), becomes either a testis or an ovary. The molecular mechanisms of human sex determination are poorly understood as known genetic defects have been identified in only a minority of patients with Disorders of Sex Development (DSD). Only a small number of transcription factors and signaling molecules, such as SRY, SOX9, DAX1, WT-1, SF-1 and WNT-4, are known to be involved in human sex determination. The overarching objective of this proposal is to identity and characterize novel sex-determining genes that will improve the diagnosis and management of human DSD patients. Disorders of sexual development encompass a very large spectrum of phenotypes, from minor malformations of the genitalia (hypospadias, cryptorchidism, hypertrophy of the clitoris) to sexual ambiguity. Taken altogether, these anomalies have an estimated frequency of 0.5% to 1%.

  • Drs. Eric Vilain, Cisco Sánchez, and Tuck Ngun are currently doing a study using the DNA of identical male twin pairs where one is gay, and one is straight. Although these twins have the same DNA sequence, they might use those genes differently, and this different use might explain their difference in sexual orientation. The lab is trying to identify which genes are regulated differently between the gay and straight twins. Please contact us if you’re interested in participating, or if you know of some twins might be interested.

  • To identify genes involved in adrenal development, we have used microarray technology to profile gene expression at critical timepoints during adrenal development. Genes that are differentially expressed between the timepoints may reveal molecular pathways and cellular processes acting during each stage of adrenal organogenesis. Sexually dimorphic characteristics of the adrenal also suggest that differences may exist in developmental pathways used by males and females. Therefore, we have also compared gene expression levels between males and females during adrenal development to identity sex-specific genetic programs. In adult mammals, sexually dimorphic gene expression in the adrenals may also lead to variations in their function. WE are currently testing this hypothesis by examining the role of sex in hypertension using a rat model.

  • Gender identity--or one’s sense of being a man or woman--is a central and fundamental human characteristic. By early childhood, people develop a gender identity that is typically congruent with the sex assigned at birth; and, this sense of gender will remain stable throughout life. While the development of our gender identity is influenced by both biological and sociological factors, we do not have a clear understanding of the relative role that each plays. Thus, we are exploring the role that genetic and neurological variability play in the development of people’s gender identity. To investigate this, we are recruiting individuals who identity as male-to-female transsexual and have not yet commenced hormone therapy. Participants will be given a battery of neuropsychological tests and will respond to a series of behavioral questionnaires. Additionally, consenting participants will undergo a structural MRI procedure and submit a sample of saliva for DNA analysis.