Sex Determination in Xenopus laevis Tadpoles and Effects of Sexual Dimorphism on Traumatic Brain Injury

This paper aims to create a standard sex determination method of Xenopus laevis tadpoles at a stage in which gonadogenesis is not yet complete however, sexual differentiation is ongoing. The methods are comprised of using tadpole tail snips, isolating DNA, conducting PCR based on six different sex-related gene identified in this paper, and then using gel electrophoresis to observe the presence of each gene within the Xenopus laevis tadpoles by observing presence of correlating band patterns on the gel. This project is meant to be utilized in terms of identifying the sex of the tadpole subjects later used in Traumatic Brain Injury experiments (courtesy of Sydnee Spruiell) to be able to observe sexual dimorphism of tadpoles upon experiencing traumatic brain injuries. Of the six sex related genes: dmrt1.L, dmrt1.S, dmw, capn5Z, ccdc69W, and scanW, the results convey that ccdc69W and scanW are the most reliable indicators of sex determination. Both genes are highly likely (r=0.80) to be present together and if expression is tested and presence is observed then the corresponding tadpole can be identified as a female. The Edema Accumulation Experiment is conducted by measuring brain water content of tadpoles after a traumatic brain injury. The results implied that while both male and female tadpoles had undergone similar percentages of water content gain, the male tadpoles had a higher level of water accumulation because their water content levels at baseline are higher to begin with than in females.