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- All Subjects: Green anole--Evolution.
- All Subjects: Zoonosis
- Genre: Academic theses
- Creators: Rupp, Shawn Michael
- Creators: Wilson, Melissa A
- Member of: Theses and Dissertations
Description
In species with highly heteromorphic sex chromosomes, the degradation of one of the sex chromosomes can result in unequal gene expression between the sexes (e.g., between XX females and XY males) and between the sex chromosomes and the autosomes. Dosage compensation is a process whereby genes on the sex chromosomes achieve equal gene expression which prevents deleterious side effects from having too much or too little expression of genes on sex chromsomes. The green anole is part of a group of species that recently underwent an adaptive radiation. The green anole has XX/XY sex determination, but the content of the X chromosome and its evolution have not been described. Given its status as a model species, better understanding the green anole genome could reveal insights into other species. Genomic analyses are crucial for a comprehensive picture of sex chromosome differentiation and dosage compensation, in addition to understanding speciation.
In order to address this, multiple comparative genomics and bioinformatics analyses were conducted to elucidate patterns of evolution in the green anole and across multiple anole species. Comparative genomics analyses were used to infer additional X-linked loci in the green anole, RNAseq data from male and female samples were anayzed to quantify patterns of sex-biased gene expression across the genome, and the extent of dosage compensation on the anole X chromosome was characterized, providing evidence that the sex chromosomes in the green anole are dosage compensated.
In addition, X-linked genes have a lower ratio of nonsynonymous to synonymous substitution rates than the autosomes when compared to other Anolis species, and pairwise rates of evolution in genes across the anole genome were analyzed. To conduct this analysis a new pipeline was created for filtering alignments and performing batch calculations for whole genome coding sequences. This pipeline has been made publicly available.
In order to address this, multiple comparative genomics and bioinformatics analyses were conducted to elucidate patterns of evolution in the green anole and across multiple anole species. Comparative genomics analyses were used to infer additional X-linked loci in the green anole, RNAseq data from male and female samples were anayzed to quantify patterns of sex-biased gene expression across the genome, and the extent of dosage compensation on the anole X chromosome was characterized, providing evidence that the sex chromosomes in the green anole are dosage compensated.
In addition, X-linked genes have a lower ratio of nonsynonymous to synonymous substitution rates than the autosomes when compared to other Anolis species, and pairwise rates of evolution in genes across the anole genome were analyzed. To conduct this analysis a new pipeline was created for filtering alignments and performing batch calculations for whole genome coding sequences. This pipeline has been made publicly available.
ContributorsRupp, Shawn Michael (Author) / Wilson Sayres, Melissa A (Thesis advisor) / Kusumi, Kenro (Committee member) / DeNardo, Dale (Committee member) / Arizona State University (Publisher)
Created2016
Description
Tuberculosis (TB) is a deadly disease that infects millions of people annually. TB has a global distribution and remains a significant cause of mortality, despite decades of eradication campaigns and antibiotic development. TB is caused by genetically similar pathogens in the Mycobacterium tuberculosis complex (MTBC), and human infections are generally caused by human-associated strains, although humans can contract animal-associated strains. Skeletal evidence of TB on archaeological human skeletal remains and evolutionary dating of MTBC genomes reveal that TB has afflicted humans for approximately 6,000 years. Previous research has shown that MTBC pathogens were introduced into the Americas through a zoonotic transmission from seals and sea lions along the coasts of South America by at least 1000 CE. Characterizing the introduction and enigmatic intercontinental spread of a successful zoonotic transmission over hundreds of years provides valuable insight into the potential of zoonotic MTBC infections. Through the recovery and phylogenomic analysis of the first ancient MTBC genomes (n = 2) from pre-contact North America, I establish that there were multiple contemporaneous MTBC lineages circulating in human populations in the Americas. The high genomic diversity and deep divergence of strains from Mesoamerica suggest that TB was endemic in the region. To reveal the impact of TB within a Mesoamerican city, I examined human skeletons (n = 137) for evidence of disease from sacrificial and natural mortality burial contexts within Tlatelolco, a ceremonial precinct and interregional marketplace at the heart of the Aztec Empire (1300-1521 CE). I found that TB disproportionately affected sacrificial victims, who also exhibited evidence of food insecurity and resource inequality. These results mirror the socioeconomic patterns of TB distribution today. Further, I sampled broadly from sacrificial victims with skeletal evidence of TB not only for biomolecular confirmation of MTBC but also to uncover associations between skeletal TB manifestation and ability to recover ancient MTBC DNA. I identify 10 additional cases of MTBC at Tlatelolco and link ancient MTBC DNA recovery to TB skeletal lesion characteristics and age-at-death of the infected individual. Overall, this body of work combines paleogenomic and paleopathological data to highlight the impact of ancient TB zoonoses.
ContributorsBlevins, Kelly Elaine (Author) / Buikstra, Jane E (Thesis advisor) / Stone, Anne C (Thesis advisor) / Ávila-Arcos, María C (Committee member) / Smith, Michael E (Committee member) / Wilson, Melissa A (Committee member) / Arizona State University (Publisher)
Created2021