Open Access. Powered by Scholars. Published by Universities.®

Cell and Developmental Biology Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 7 of 7

Full-Text Articles in Cell and Developmental Biology

Species Delimitation Of Slimy Salamanders, Plethodon Kisatchie And Plethodon Mississippi, Across The Lower Mississippi River, Brock Hunter Stevenson Mar 2024

Species Delimitation Of Slimy Salamanders, Plethodon Kisatchie And Plethodon Mississippi, Across The Lower Mississippi River, Brock Hunter Stevenson

Master's Theses

Species are fundamental units of biodiversity yet delimiting species can be challenging. Slimy Salamanders of the Plethodon glutinosus species complex are a classic example of cryptic species for which species boundaries and relationships have proved difficult to determine. Once thought to be a single species ranging across the eastern United States, protein analysis revealed high genetic divergences among geographically distinct groups of populations, leading to 16 species being recognized within the group. Two of these species, the Louisiana Slimy Salamander (Plethodon kisatchie) and the Mississippi Slimy Salamander (Plethodon mississippi), are closely related but occur on opposite sides of the Mississippi …


Genetic Evaluation Of The Current Distribution And Possible Diffrentations Between Lasiurus Borealis And Lasiurus Frantzii In Southwestern North America, Zeinab M. Haidar Jan 2023

Genetic Evaluation Of The Current Distribution And Possible Diffrentations Between Lasiurus Borealis And Lasiurus Frantzii In Southwestern North America, Zeinab M. Haidar

Cal Poly Humboldt theses and projects

Several recent accounts of overlap and historic misidentifications regarding two species of the genus Lasiurus, Western red bat (Lasiurus frantzii) and Eastern red bat (Lasiurus borealis), have cast doubt on our understanding of their distribution, assumed spatial allopatry, and interactions in the United States Southwest. With the use of morphometrics and genetic sequencing, utilizing tissue collected from specimens throughout California and adjoining states, we have reassessed the current distribution, best practices for field identification, and genetic differentiation between both species. Appropriate species classification by region was achieved utilizing mitochondrial DNA, targeting the cytochrome c oxidase …


Identifying The Human Homologs Of Yeast Rab Proteins Ypt10 & Ypt11 And A Global-Scale Louse Endosymbiont Genome Variation, Nathaniel P. Smith Jan 2022

Identifying The Human Homologs Of Yeast Rab Proteins Ypt10 & Ypt11 And A Global-Scale Louse Endosymbiont Genome Variation, Nathaniel P. Smith

Theses and Dissertations

Amyotrophic lateral sclerosis (ALS) is a late-onset fatal neurodegenerative disease that causes loss of upper and/or lower motor neurons, and currently has no treatment or cure available. Over 90% of cases occur spontaneously with unknown causes, highlighting the complexity of the disease, and only 10% of cases are linked to heritable genetic mutations. Numerous ALS-linked genes are conserved through evolution, and model organisms may therefore provide opportunities to understand disease pathology at a molecular or cellular level, proving instrumental in identifying therapeutic targets. ALS subtype 8 (ALS8) is caused by an autosomal dominant P56S mutation in the VAPB gene that …


Dynamics Of Hybrid Zones At A Continental Scale, Bradley T. Martin May 2021

Dynamics Of Hybrid Zones At A Continental Scale, Bradley T. Martin

Graduate Theses and Dissertations

Hybridization has traditionally been viewed as a happenstance that negatively impacts populations, but is now recognized as an important evolutionary mechanism that can substantially impact the evolutionary trajectories of gene pools, influence adaptive capacity, and contravene or reinforce divergence. Physiographic processes are important drivers of dispersal, alternately funneling populations into isolation, promoting divergence, or facilitating secondary contact of diverged populations, increasing the potential for hybridization. In North America, glacial-interglacial cycles and geomorphological changes have provided a dynamic backdrop over the last two million years that promoted such oscillations of population contraction and expansion. These biogeographic processes have resulted in regional …


Comparative Phylogeography, Taxonomy, And Neuroanatomy Of Montane Chameleons In The Albertine Rift, Central Africa, Daniel Hughes Jan 2018

Comparative Phylogeography, Taxonomy, And Neuroanatomy Of Montane Chameleons In The Albertine Rift, Central Africa, Daniel Hughes

Open Access Theses & Dissertations

How do traits vary across the tree of life? Our ability to address this question is diminished if: A taxonomic group has a poorly sampled phylogeny, a species goes extinct before their systematic position is resolved, or a trait is inadequately characterized for detailed studies. In the current era of mass extinction, it is imperative to not only accelerate species discovery through traditional studies in taxonomy and expeditionary research, but also to increase rescue efforts for all types of data before poorly understood species and potentially undescribed traits are lost. Here, an integrative taxonomic approach was used and novel methods …


Systematics Of Leptopelis (Anura: Arthroleptidae) From The Itombwe Plateau, Eastern Democratic Republic Of The Congo, Francisco Portillo Jan 2012

Systematics Of Leptopelis (Anura: Arthroleptidae) From The Itombwe Plateau, Eastern Democratic Republic Of The Congo, Francisco Portillo

Open Access Theses & Dissertations

Leptopelis, a genus of Central African treefrogs, includes 51 species that live in tropical forests and savannas. Currently, only two species of Leptopelis are known from the poorly explored Itombwe Plateau in eastern Democratic Republic of the Congo (DRC). Itombwe is renowned among conservationists for its rich and endemic amphibian fauna, including: Xenopus itombwensis, Chrysobatrachus cupreonitens, Laurentophryne parkeri, Hyperolius leleupi and at least three species of Arthroleptis. Evolutionary relationships of Itombwe Leptopelis were examined by sequencing two mitochondrial genes (16S: 557 bp [base pairs], cyt b: 620 bp) and one nuclear gene (RAG1: 761 bp). Results recovered strong support for …


Molecular Systematics Of The Middle American Genus Hypopachus (Anura: Microhylidae), Eli Greenbaum, Eric N. Smith, Rafael O. De Sá Nov 2011

Molecular Systematics Of The Middle American Genus Hypopachus (Anura: Microhylidae), Eli Greenbaum, Eric N. Smith, Rafael O. De Sá

Biology Faculty Publications

We present the first phylogenetic study on the widespread Middle American microhylid frog genus Hypopachus. Partial sequences of mitochondrial (12S and 16S ribosomal RNA) and nuclear (rhodopsin) genes (1275 bp total) were analyzed from 43 samples of Hypopachus, three currently recognized species of Gastrophryne, and seven arthroleptid, brevicipitid and microhylid outgroup taxa. Maximum parsimony (PAUP), maximum likelihood (RAxML) and Bayesian inference (MrBayes) optimality criteria were used for phylogenetic analyses, and BEAST was used to estimate divergence dates of major clades. Population-level analyses were conducted with the programs NETWORK and Arlequin. Results confirm the placement of Hypopachus …