The Genetics Underlying Male-Female Facial Sexual Dimorphism
Date
2021-12-21
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
The genetic mechanisms underlying facial sexual dimorphism are currently unknown. My thesis addresses this gap by shedding light on the genetic and biological mechanisms underlying sexual dimorphism in human facial shape, as well as normal facial variation more broadly. I evaluated the shape differences between males and females, scored their shapes for sexual dimorphism, and looked for genetic loci and genes that had significant associations with sexually dimorphic facial shape. While none of the SNPs reached genome-wide significance, testing revealed seven independent signals with suggestive associations (p < 1 × 10-5) to facial sexual dimorphism, spanning coding regions in four different genes. Three of these genes, RBFOX1, CACNA2D3 and ATP6V1E1, have previously been implicated in processes of craniofacial development. I also examined the shapes and genetic aetiologies associated with sex chromosome aneuploidies, Turner syndrome (X0) and Klinefelter syndrome (XXY), which yielded no clear indication of the role of the X chromosome in sexual dimorphism of the face. These findings support the most recent evidence that the same genes influence facial sexual dimorphism in both males and females. Furthermore, by identifying genes previously linked to normal facial variation, I provide preliminary evidence for developmental mechanisms underlying shared variation in facial sexual dimorphism between the sexes. Only by properly understanding the mechanisms underlying facial sexual dimorphism will we be able to form a complete picture of its role in human evolution.
Description
Keywords
Geometric morphometrics, GWAS, Facial sexual dimorphism
Citation
Da Silva, C. (2021). The Genetics Underlying Male-Female Facial Sexual Dimorphism (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.