Using Genomic DNA of Anolis Carolinensis to Determine Sex in Juvenile Lizards

Location

CSU Ballroom

Start Date

12-4-2022 2:00 PM

End Date

12-4-2022 3:30 PM

Student's Major

Biological Sciences

Student's College

Science, Engineering and Technology

Mentor's Name

Rachel Cohen

Mentor's Department

Biological Sciences

Mentor's College

Science, Engineering and Technology

Description

Steroid hormones, such as testosterone and estradiol, have important roles in vertebrate development by producing sex-specific structures, including the brain and copulatory system. Green anole lizards (Anolis carolinensis) take approximately 28 days to hatch after an egg is laid and uses the XY sex-determination system (similar to humans). Male anoles possess copulatory organs called hemipenes that are present in both embryonic male and females until embryonic day 10, when the hemipenes begin to regress in females. Previous work has shown that estradiol treatment during embryonic day 10 and 13 can cause the hemipenes to regress in male embryos. Although it is well established that estradiol masculinizes the rodent brain, little is known about how estradiol impacts brain development in lizards. Our overall goal is to examine the impact of estradiol on green anole brain development, using hemipene regression as a positive control for treatment. To complete this experiment, we must be able to determine the sex of each hatchling. Hatchling torsos were sectioned and stained with hematoxylin and eosin, then examined under the microscope to determine sex. However, it was difficult to determine which gonad was present in each hatchling, as the histology of testes and ovaries is very similar in juvenile lizards. Therefore, we have begun studies to isolate genomic DNA from hatchlings and determine the sex of each individual using PCR amplification of sex-specific genes. Once we have established this technique, we plan to continue examining the hemipenes and brain for effects of estradiol treatment. This study will help us determine whether estradiol is necessary to masculinize the anole brain, which will provide evidence for a role of estradiol in brain masculinization across vertebrates.

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Apr 12th, 2:00 PM Apr 12th, 3:30 PM

Using Genomic DNA of Anolis Carolinensis to Determine Sex in Juvenile Lizards

CSU Ballroom

Steroid hormones, such as testosterone and estradiol, have important roles in vertebrate development by producing sex-specific structures, including the brain and copulatory system. Green anole lizards (Anolis carolinensis) take approximately 28 days to hatch after an egg is laid and uses the XY sex-determination system (similar to humans). Male anoles possess copulatory organs called hemipenes that are present in both embryonic male and females until embryonic day 10, when the hemipenes begin to regress in females. Previous work has shown that estradiol treatment during embryonic day 10 and 13 can cause the hemipenes to regress in male embryos. Although it is well established that estradiol masculinizes the rodent brain, little is known about how estradiol impacts brain development in lizards. Our overall goal is to examine the impact of estradiol on green anole brain development, using hemipene regression as a positive control for treatment. To complete this experiment, we must be able to determine the sex of each hatchling. Hatchling torsos were sectioned and stained with hematoxylin and eosin, then examined under the microscope to determine sex. However, it was difficult to determine which gonad was present in each hatchling, as the histology of testes and ovaries is very similar in juvenile lizards. Therefore, we have begun studies to isolate genomic DNA from hatchlings and determine the sex of each individual using PCR amplification of sex-specific genes. Once we have established this technique, we plan to continue examining the hemipenes and brain for effects of estradiol treatment. This study will help us determine whether estradiol is necessary to masculinize the anole brain, which will provide evidence for a role of estradiol in brain masculinization across vertebrates.

Recommended Citation

Kraudy, Ashley and Nadia Lowery. "Using Genomic DNA of Anolis Carolinensis to Determine Sex in Juvenile Lizards." Undergraduate Research Symposium, Mankato, MN, April 12, 2022.
https://cornerstone.lib.mnsu.edu/urs/2022/poster-session-02/9