Intraspecific Genetic Variation in Green Salamanders (Aneides aeneus) at Bays Mountain Park
Abstract
Amphibians are declining globally due to various site-specific and regional factors including disease, over-collection, climate change, and large-scale habitat loss and degradation. Obtaining complete taxonomic information on threatened species is critical for accurately identifying these organisms and developing effective conservation strategies. Green salamanders (Plethodontidae: Aneides aeneus) are vulnerable cryptic species in the Southern Appalachian Mountains. This study aimed to characterize the genetic diversity in A. aeneus at Bays Mountain Park (BMP) in Kingsport, Tennessee to better understand the aeneus complex and promote conservation initiatives. It was hypothesized that individuals in BMP would exhibit genetic similarity to those in the characterized northern lineage but could demonstrate genetic isolation. Previous mitochondrial and nuclear phylogenetic analysis determined four distinct lineages within the complex: Northern Apps, Southern Apps, Hickory Nut Gorge (HNG), and Blue-Ridge Escarpment (BRE) with genetic analysis concluding the HNG green salamander is a separate species. The goal of this project is to determine where the BMP population resides within these lineages. Tail tips were collected from individuals found in BMP from April to October 2024. Locality data including longitude, latitude, elevation, description of the habitat, and pictures or notes of distinct morphological differences were recorded for all sampled individuals. DNA was extracted from each tail-tip followed by PCR to amplify two mitochondrial genes: Cytochrome b (cytb) and NADH dehydrogenase subunit 4 (nd4). Gel electrophoresis verified amplification before sending the samples off for Sanger sequencing. The resulting sequences were cleaned, aligned, and assembled into contigs before running a multiple-sequence alignment using Geneious. Maximum likelihood (ML) analyses were applied based on SNP allele frequencies to generate a phylogenetic tree demonstrating the genetic relationship between sequenced individuals. Results support the hypothesis that the BMP population exhibits high genetic similarity to the northern lineage, consistent with its position on the phylogenetic tree.
Start Time
16-4-2025 9:00 AM
End Time
16-4-2025 10:00 AM
Room Number
303
Presentation Type
Oral Presentation
Presentation Subtype
Grad/Comp Orals
Presentation Category
Science, Technology and Engineering
Faculty Mentor
Joe Bidwell
Intraspecific Genetic Variation in Green Salamanders (Aneides aeneus) at Bays Mountain Park
303
Amphibians are declining globally due to various site-specific and regional factors including disease, over-collection, climate change, and large-scale habitat loss and degradation. Obtaining complete taxonomic information on threatened species is critical for accurately identifying these organisms and developing effective conservation strategies. Green salamanders (Plethodontidae: Aneides aeneus) are vulnerable cryptic species in the Southern Appalachian Mountains. This study aimed to characterize the genetic diversity in A. aeneus at Bays Mountain Park (BMP) in Kingsport, Tennessee to better understand the aeneus complex and promote conservation initiatives. It was hypothesized that individuals in BMP would exhibit genetic similarity to those in the characterized northern lineage but could demonstrate genetic isolation. Previous mitochondrial and nuclear phylogenetic analysis determined four distinct lineages within the complex: Northern Apps, Southern Apps, Hickory Nut Gorge (HNG), and Blue-Ridge Escarpment (BRE) with genetic analysis concluding the HNG green salamander is a separate species. The goal of this project is to determine where the BMP population resides within these lineages. Tail tips were collected from individuals found in BMP from April to October 2024. Locality data including longitude, latitude, elevation, description of the habitat, and pictures or notes of distinct morphological differences were recorded for all sampled individuals. DNA was extracted from each tail-tip followed by PCR to amplify two mitochondrial genes: Cytochrome b (cytb) and NADH dehydrogenase subunit 4 (nd4). Gel electrophoresis verified amplification before sending the samples off for Sanger sequencing. The resulting sequences were cleaned, aligned, and assembled into contigs before running a multiple-sequence alignment using Geneious. Maximum likelihood (ML) analyses were applied based on SNP allele frequencies to generate a phylogenetic tree demonstrating the genetic relationship between sequenced individuals. Results support the hypothesis that the BMP population exhibits high genetic similarity to the northern lineage, consistent with its position on the phylogenetic tree.