Peromyscus Karyotypic Evolution in Speciation and Disease

Date of Completion

January 2011


Biology, Genetics




Chromosomal rearrangements can mutate genome structure and gene expression patterns through amplifying and/or eliminating genetic material, and by modifying the regulatory elements that control transcription. Reproductive isolation and tumorigenic karyotypic transformation can be initiated through the same structural rearrangements, therefore karyotypic change can drive both speciation and carcinogenesis. Several Peromyscus species provide natural examples of the mechanisms involved in karyotypic evolution during speciation and tumorigenic transformation. This dissertation produced the Peromyscus - Mus synteny map and the first rodent-specific breakpoint analysis, which generated three novel ancestral karyotypes and identified patterns of breakpoint reuse and karyotypic orthoselection that defined speciation trajectory during rodent evolution. This dissertation also clarified the Peromyscus melanophrys sex determining system and in doing so, identified an unusual late-replicating XY to autosome translocation with potential transcriptional activity. In addition, this dissertation introduces the Peromyscus leucopus Harderian gland tumor system, which is characterized by rampant gene amplification, highly derived karyotypic evolution and rapid metastasis. ^