The Evolution of Sex Determination and the DMRT1 Gene in the Japanese Gecko (Gekko japonicus)

There are different sex-determining mechanisms in our environment, which are separated into two groups known as genotypic sex determination (GSD) and environmental sex determination. The most well-known mechanism in the ESD group is temperature-dependent sex determination (TSD). In this study, the presence of the Doublesex and mab-3-related Transcription Factor (<em>Dmrt1</em>) gene was observed during embryonic development in geckos with a TSD mechanism. To do this, I observed the rate of transcription of the <em>Dmrt1</em> gene in the Gecko species <em>Gekko japonicus</em>. Pregnant geckos were caught around Nanjing, China. Once the females laid their eggs, the eggs were then randomly placed in one of three different temperature regimes (24°C, 28°C, 32°C). The embryos, the main target, were dissected at two points during development and total RNA was extracted. A relative rate of transcription of the <em>Dmrt1</em> gene was assessed using quantitative PCR (qPCR). I was not able to quantify the use of the <em>Dmrt1</em> gene between males and females. However, my study does not allow me to exclude the possibility that <em>G. japonicus</em> may use a GSD system with a TSD override, instead of the earlier proposed TSD system.

Name thesis:degree_name

Master of Science (MS)

Discipline thesis:degree_discipline

Biology

Year dc:date.available

2015

Author dc:creator

• Mullen, Lisa-Marie

Contributors dc:contributor

• Lixing Sun
• April K. Binder
• Joseph Lorenz

• Sex Determination
• DMRT1
• reptile
• TSD
• Ecology and Evolutionary Biology
• Evolution
• Genetics

Language dc:language

English

Repository record dc:identifier

https://digitalcommons.cwu.edu/etd/229

OAI identifier oai:identifier

oai:digitalcommons.cwu.edu:etd-1239