Date of Award

Spring 4-17-2026

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Biomedical Engineering

First Advisor

Tony Gamble

Second Advisor

Allison Abbott

Third Advisor

Lisa Petrella

Abstract

ABSTRACT IDENTIFICATION OF SEX CHROMOSOMES IN THE GENUS LEPIDODACTYLUS Zuleihat Y. Idris, M.S Marquette University, 2026 Sex determination in vertebrates is remarkably diverse and is characterized by frequent evolutionary transitions between genetic sex determination (GSD) and environmental sex determination (ESD). Within reptiles, geckos (Gekkota) exhibit the most diverse sex determination mechanism in vertebrates. Although geckos are the target of more recent research, most lineages still lack identifiable sex-determining mechanisms. This gap in knowledge has limited the understanding of the diversity and evolution of sex determination in vertebrates. In this study, an automated pipeline (FnPiPER) and whole-genome resequencing from male and female individuals were used to estimate the genetic differentiation (FST), nucleotide diversity (pi), and read depth in two species of the genus Lepidodactylus: Lepidodactylus babuyanensis and Lepidodactylus pantai. The pipeline cleans the raw sequencing reads, indexes the reference genome, maps the cleaned reads to the reference genome, computes, and plots the genetic differentiation (FST), nucleotide diversity (pi), and read depth metrics. The result identified novel ZW sex chromosomes in both species of Lepidodactylus. L. pantai's sex chromosome was identified on chromosome 4, and L. babuyanensis' sex chromosome was identified on chromosome 16. A partially differentiated sex chromosome in both species confirmed a sex chromosome transition in the genus.

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