Dissertations, Theses, and Capstone Projects

Date of Degree

6-2024

Document Type

Dissertation

Degree Name

Ph.D.

Program

Biology

Advisor

Jessica L Ware

Committee Members

J. Stephen Gosnell

Christopher D. Beatty

Manpreet K. Kohli

Rachel Skinner

Subject Categories

Ecology and Evolutionary Biology | Entomology

Keywords

New Zealand, Tanypteryx, Genomics

Abstract

The Anisoptera (Insecta: Odonata), or dragonflies exhibit diverse life histories and diversification patterns, with the family Petaluridae standing out as particularly unique. Comprising only 11 extant species, all of which inhabit increasingly threatened fen habitats, Petaluridae are known for their longevity, which can exceed five years, semi-terrestrial lifestyle, and remarkable physical size, ranking among the largest insects on Earth. Despite the evolutionary peculiarities of this family, no previous genomic studies have investigated the Petaluridae. This work presents two high-quality genome sequences and a targeted enrichment dataset to explore the chromosome architecture of Petaluridae, identifies genomic adaptations associated with their distinctive life history, and resolves the phylogenetic relationships within the Petaluridae. By identifying regions of synteny between the genome of the petalurid Tanypteryx hageni and three other species from across the Odonate tree of life, this work reveals few changes in genome architecture across 250 million years of Odonata evolution and highlights the unique role of repetitive elements in shaping Petaluridae genomes. Comparative genomics work including T. hageni, another Petaluridae Uropetala carovei, and five other Odonata uncovers shared expansions in gene families unique to the Petaluridae. These uniquely expanded gene families are related to biological functions such taste perception and apoptosis regulation, which can potentially linked to their semi-terrestrial lifestyle and longevity of the Petaluridae. Furthermore, integration of target enrichment data with genome sequences and previously sequenced transcriptomes allows for the resolution of the Petaluridae phylogeny, confirming the ancient origins of lineages within this family and historical correlation with continental drift, the closing of seaways, and the development of mountain ranges. In totality, this work lays the foundation for future study of the evolution of this model family.

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