An expressed sequence tag (EST) library for Drosophila serrata, a model system for sexual selection and climatic adaptation studies

The native Australian fly Drosophila serrata belongs to the highly speciose montium subgroup of the melanogaster species group. It has recently emerged as an excellent model system with which to address a number of important questions, including the evolution of traits under sexual selection and traits involved in climatic adaptation along latitudinal gradients. Understanding the molecular genetic basis of such traits has been limited by a lack of genomic resources for this species. Here, we present the first expressed sequence tag (EST) collection for D. serrata that will enable the identification of genes underlying sexually-selected phenotypes and physiological responses to environmental change and may help resolve controversial phylogenetic relationships within the montium subgroup

GENOMICS OF THE GLOBALLY DISTRIBUTED ECHINOID GENUS Tripneustes

Ph.D. Thesis. University of Hawaiʻi at Mānoa 2018

Deep Genomic-Scale Analyses of the Metazoa Reject Coelomata: Evidence from Single- and Multigene Families Analyzed Under a Supertree and Supermatrix Paradigm

Solving the phylogeny of the animals with bilateral symmetry has proven difficult. Morphological studies have suggested a variety of alternative hypotheses, of which, Hyman’s Coelomata hypothesis has become the most established. Studies based on 18S rRNA have failed to endorse Coelomata, supporting instead the rearrangement of the protostomes into two new clades: the Lophotrochozoa (including, e.g., the molluscs and the annelids) and the Ecdysozoa (including the Panarthropoda and most pseudocoelomates, such as the nematodes and priapulids). Support for this new animal phylogeny has been attained from expressed sequence tag studies, although these generally have a limited gene sampling. In contrast, deep genomic-scale analyses have often supported Coelomata. However, these studies are problematic due to their limited taxonomic sampling, which could exacerbate tree reconstruction artifacts

Development of a molecular detection assay for accurate identification of five economically important tephritid species of commercial fruit in South Africa

Genetic

Patterns and Processes Shaping Avian Diversity in the Hawaiian Islands

Ph.D

Determining Bioindicators for Coastal Tidal Marsh Health Using the Food Web of Larvae of the Greenhead Horse Fly (Tabanus nigrovittatus)

The greenhead horse fly Tabanus nigrovittatus Macquart is native to coastal marshlands from Texas to Nova Scotia. The larvae are apex invertebrate predators and their development is dependent on the food web in the soil. Surveillance of T. nigrovittatus after the 2010 Deepwater Horizon oil spill in the Gulf of Mexico showed population crashes of adults in the coastal marshes of East Louisiana near places where oil made landfall, but not in West Louisiana where the oil did not reach. Sediment collection in 2011 from West and East Louisiana revealed larval population crashes in the Eastern coastal region. We hypothesized that due to the oil contamination a critical component of the food web of the larvae was destroyed and/or direct toxicity of the oil led to tabanid larval population crashes. With the aim of deciphering the tabanid larval food web in the Louisiana marshes, we used 18SrRNA metagenomics to identify the components of the food web in larval guts (n=16) and the surrounding sediment (n=25) from East and West Louisiana. An approximately 400 bp region at the 5’ end of the 18SrRNAgene was sequenced using the Illumina MiSeq sequencing platform. Downstream analysis was conducted in QIIME (v1.9). Effect of oil, sediment biochemistry and sediment toxicity on larvae and their food web was determined to explain larval decline in East Louisiana. We found insects and fungi to dominate the tabanid larval guts. Insects identified belonged to the families Drosophilidae, Culicidae and Tabanidae. Bioindicators of minimally oiled sediments are Hymenostomatia (Tetrahymena), Bivalvia (mollusks), Maxillopoda (Crustacea) and Peronosporomycetes (fungus like eukaryotes). “Phylum” Opisthokonta dominance in sediments is an indicator of larval presence in West Louisiana but not the East. Oil contamination, sediment biochemistry and toxicity could not explain larval population crashes in the East. Decline in the adult population led to fewer breeders and subsequently fewer larvae

Evolutionary diversification and historical biogeography of orchidaceae in Central America with emphasis on Costa Rica and Panama

In this thesis, I targeted the orchid genus Lepanthes, one of the six genera of angiosperms that surpasses 1,000 species in the Neotropics, as a study model to investigate the evolutionary processes that promoted species diversifications. To investigate this, we improved the taxonomy of the group integrating a solid phylogenetic framework with morphological evolution, assessing inter-specific relationships in species complexes with hundreds of DNA markers using anchored hybrid enrichment approach, and describing new species. In addition, we addressed the pollination of Trichosalpinx through the study of floral anatomy, pollinator behavior, and floral traits. Trichosalpinx flowers are pollinated exclusively by female biting midges that are attracted by the small quantities of proteins secreted on the flowers. Finally, we inferred the biogeographical history and diversification dynamics of the two largest Neotropical orchid groups (Cymbidieae and Pleurothallidinae), using densely sampled phylogenies coupled with geological datasets and discussed the impact of biogeographical events and orogeny on the species richness of Lepanthes. Species diversification is correlated with Andean orogeny, and multiple migrations and recolonizations across the Andes indicate that mountains do not constrain orchid dispersal over long timescales. This thesis provides new insights into the complex evolution of one of the most species-rich angiosperm.Leiden University/[]//Países BajosCentro de Biodiversidad Naturalis/[]//Países BajosUniversidad de Costa Rica/[]/UCR/Costa RicaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Jardín Botánico Lankester (JBL