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Plant Sciences

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Full-Text Articles in Biology

Population Genetics Of Transposable Element Load: A Mechanistic Account Of Observed Overdispersion, Gregory Conradi Smith, Ron D. Smith, Joshua Puzey Jul 2022

Population Genetics Of Transposable Element Load: A Mechanistic Account Of Observed Overdispersion, Gregory Conradi Smith, Ron D. Smith, Joshua Puzey

Arts & Sciences Articles

In an empirical analysis of transposable element (TE) abundance within natural populations of Mimulus guttatus and Drosophila melanogaster, we found a surprisingly high variance of TE count (e.g., variance-to-mean ratio on the order of 10 to 300). To obtain insight regarding the evolutionary genetic mechanisms that underlie the overdispersed population distributions of TE abundance, we developed a mathematical model of TE population genetics that includes the dynamics of element proliferation and purifying selection on TE load. The modeling approach begins with a master equation for a birth-death process and extends the predictions of the classical theory of TE dynamics in …


Climate Change And Conservation Of Milkweed: Evidence Of Extensive Admixture Between Common Milkweed And Poke Milkweed, Elizabeth Davies May 2022

Climate Change And Conservation Of Milkweed: Evidence Of Extensive Admixture Between Common Milkweed And Poke Milkweed, Elizabeth Davies

Undergraduate Honors Theses

Global climate change can drive many changes in species interactions. One primary way it affects species is by changing climates, causing species to expand their ranges and allowing them to interact with species from whom they were previously isolated. In plants, new species interactions can result in hybridization – the creation of hybrid offspring between two separate species. This hybridization can increase gene flow between the species and lead to introgression, the transfer of genetic material from one species to another through hybrid backcrossing with the parent species. My thesis investigates hybridization in the model system Asclepias (milkweed) by analyzing …


Investigating The Effect Of Longhorned Milkweed Beetle Larval Root Feeding On Resprouting In Common Milkweed, Margaret Donnan May 2022

Investigating The Effect Of Longhorned Milkweed Beetle Larval Root Feeding On Resprouting In Common Milkweed, Margaret Donnan

Undergraduate Honors Theses

Clonal reproduction is an important form of reproduction for many plants, and plants can grow clonally through a variety of methods, such as belowground stems, specialized organs, or adventitious buds on their roots (Herben and Klimešová 2020). In plants that reproduce via buds on their roots, researchers have shown that damage to roots can stimulate bud production and sprouting (Bartušková and Klimešová 2010). Common milkweed (Asclepias syriaca) is a root- sprouting perennial plant that receives yearly damage to its roots via the feeding of the larvae of the specialist longhorned milkweed beetle (Tetraopes tetrophthalmus) (Erwin et al. 2013). In this …


Characterizing The Microbiome Of Floral Nectar Of Asclepias Syriaca And Other Asclepias Species, Heather Natterer May 2021

Characterizing The Microbiome Of Floral Nectar Of Asclepias Syriaca And Other Asclepias Species, Heather Natterer

Undergraduate Honors Theses

In recent decades, Danaus plexippus (the monarch butterfly) has experienced a drastic decrease in population size due to urbanization, climate change, and habitat loss. The primary habitat and food source of D. plexippus is plant species that are within the genus Asclepias (milkweed). The preservation and propagation of Asclepias spp. is necessary to combat D. plexippus’s population declines. A plant’s reproductive success is dependent upon its ability to attract pollinators, which is linked to the plant’s nectar qualities. We propose that, in turn, these nectar qualities may be influenced by the nectar microbiome. This study aims to better understand the …


The Regulatory Network For Petal Anthocyanin Pigmentation Is Shaped By The Myb5a/Negan Transcription Factor In Mimulus, Xingyu Zheng, Kuenzang Om, Kimmy A. Stanton, (...), Gregory D. Conradi Smith, Joshua R. Puzeyn, Et Al. Feb 2021

The Regulatory Network For Petal Anthocyanin Pigmentation Is Shaped By The Myb5a/Negan Transcription Factor In Mimulus, Xingyu Zheng, Kuenzang Om, Kimmy A. Stanton, (...), Gregory D. Conradi Smith, Joshua R. Puzeyn, Et Al.

Arts & Sciences Articles

Much of the visual diversity of angiosperms is due to the frequent evolution of novel pigmentation patterns in flowers. The gene network responsible for anthocyanin pigmentation, in particular, has become a model for investigating how genetic changes give rise to phenotypic innovation. In the monkeyflower genus Mimulus, an evolutionarily recent gain of petal lobe anthocyanin pigmentation in M. luteus var. variegatus was previously mapped to genomic region pla2. Here, we use sequence and expression analysis, followed by transgenic manipulation of gene expression, to identify MYB5a—orthologous to the NEGAN transcriptional activator from M. lewisii—as the gene responsible …


Subgenome Dominance In An Interspecific Hybrid, Synthetic Allopolyploid, And A 140-Year-Old Naturally Established Neo-Allopolyploid Monkeyflower, Patrick P. Edger, Ronald Smith, Micheal R. Mckain, (...), Gregory D. Conradi Smith, Joshua R. Puzey Sep 2017

Subgenome Dominance In An Interspecific Hybrid, Synthetic Allopolyploid, And A 140-Year-Old Naturally Established Neo-Allopolyploid Monkeyflower, Patrick P. Edger, Ronald Smith, Micheal R. Mckain, (...), Gregory D. Conradi Smith, Joshua R. Puzey

Arts & Sciences Articles

Recent studies have shown that one of the parental subgenomes in ancient polyploids is generally more dominant, having retained more genes and being more highly expressed, a phenomenon termed subgenome dominance. The genomic features that determine how quickly and which subgenome dominates within a newly formed polyploid remain poorly understood. To investigate the rate of emergence of subgenome dominance, we examined gene expression, gene methylation, and transposable element (TE) methylation in a natural, <140-year-old allopolyploid (Mimulus peregrinus), a resynthesized interspecies triploid hybrid (M. robertsii), a resynthesized allopolyploid (M. peregrinus), and progenitor species (M. guttatus …