Biology subjects

Kolomyjec, S. H.

Publications and source records attributed to Kolomyjec, S. H..

3 recordsLinked to original sources

bioRxiv2025

Genomic connectivity and adaptation signals of the freshwater sponge Ephydatia muelleri across its distribution

1.Freshwater sponges fulfill critical ecological functions, including maintaining water quality, regulating nutrient dynamics, offering habitats for diverse taxa, and serving as a vital food source for various species. However, their patterns of dispersal and genetic connectivity remain inadequately understood, posing significant challenges to effective conservation assessments. We examined genetic connectivity and genetic adaptation to local environmental conditions in Ephydatia muelleri across its geographic range using ddRADseq-derived SNPs from 106 individuals collected from 11 localities spanning North America, Europe, and Asia. Analysis of 3,182 neutral SNPs revealed low connectivity and strong genetic structure among regions within two main genetic clusters of North America and Eurasia, while 115 SNPs identified to be under selection showed considerable evidence for differentiated, polygenic adaptation to light and temperature conditions across sampled locations, as well as selection on gene regulatory processes. These findings align with the "monopolization hypothesis", suggesting that historical climatic and geological conditions of the Last Glacial Maximum, including habitat expansion, contraction, and natural barriers, have contributed more to the current genetic structure of E. muelleri populations than contemporary gene flow, which is restricted by monopolistic habitat colonization by this species. Our results provide novel support for ecological theory on dispersal in aquatic invertebrates, as well as insights into the plasticity of E. muelleri in the face of varying environmental conditions that are fundamentally important for freshwater ecosystem conservation.

evolutionary biology↗

bioRxiv2022

Analysis of the CYP1A2 caffeine metabolism gene in the student population at Lake Superior State University

85% of Americans drink caffeinated beverages on a daily basis. Each individual responds differently to caffeine depending on age, gender, diet, and ethnicity. Caffeinated beverages cause insomnia in some people, but not in others due to differences in the rate of caffeine metabolism. This study examines the variation in the caffeine metabolism of Lake Superior State University (LSSU) students. My hypothesis was that LSSU student allele frequencies would match those of the general population: 47.5% fast, 41.0% medium, and 11.5% slow caffeine metabolism. 200 LSSU students were sampled via buccal swabs. DNA was successfully isolated from 164 samples. Participants filled out a demographic questionnaire entailing caffeine intake, ethnicity, and sex. The CYP1A2 gene was amplified via standard PCR prior to genotyping by restriction digest and gel electrophoresis. The APAI restriction enzyme was used to determine the genotype of the rs762551 single nucleotide polymorphism (SNP), while the SACI enzyme was used as a positive digestion control. Overall, results showed a total of 42.7% fast, 44.5% medium, and 12.8% slow metabolizers. Of special note is that 24 of the 164 students sampled were of Native American heritage, an important yet underrepresented group in human genomics. This study provides the first reported look at the CYP1A2 variation within this North American subpopulation with metabolism rates being 50% fast, 33.3% medium, and 16.7% slow. The results confirm my initial hypothesis that the variation of caffeine metabolism gene frequencies for the LSSU student population would be representative of published allele frequencies for the general population.

genetics↗

bioRxiv2020

Phylogenetic analysis of Michigan's freshwater sponges (Porifera, Spongillidae) using extended COI mtDNA sequences

Kolomyjec et al. (2020). Phylogenetic analysis of Michigan’s freshwater sponges (Porifera, Spongillidae) using extended COI mtDNA sequences. – Zoologica Scripta, 00, 000-000. The phylogenetic relationships of eight species of freshwater sponges sampled throughout the State of Michigan in the North American Great Lakes region were examined as part of a Course-based Undergraduate Research Experience (CURE). An extended version of the standard cytochrome oxidase subunit I (COI) metazoan DNA was used for sequencing and Bayesian phylogenetic inference. The extended gene region (COI-ext) produces a 1,200 bp amplicon instead of the standard 640 bp fragment which compensates for the standard amplicon’s low informatics value in Phylum Porifera. The species examined clustered into strongly supported monophyletic species groups within the family Spongillidae. This study represents the first look at the phylogenetic relationships of freshwater sponges in the Great Lakes Region.Per Kolomyjec, College of Science and the Environment, Lake Superior State University, 650 W Easterday Ave., Sault Sainte Marie, MI 49783, USA. E-mail skolomyjec{at}lssu.eduCompeting Interest StatementThe authors have declared no competing interest.View Full Text

zoology↗