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Duryea, M. C.

Publications and source records attributed to Duryea, M. C..

2 recordsLinked to original sources

Undergraduate research project uncovers a novel strain of amphibian chytrid fungus in the Northeastern United States

Investigation of the genetic variation of Batrachochytrium dendrobatidis (Bd or chytrid fungus) in New Hampshire (NH) in the northeastern U.S. has shown the presence of genetic mutations which are currently undocumented in the literature. DNA was collected as part of a long-term monitoring project in New Hampshire to test for the presence of Bd in amphibian populations. In this monitoring project, we are detecting the presence of Bd in multiple populations, but the observed amphibians do not appear to have increased mortality or other symptoms related to the fungus. To further investigate the strain of Bd affecting NH amphibians, we sequenced samples that were collected in 2019, as part of your yearly monitoring effort. Utilizing the Basic Local Alignment Search Tool (BLAST) and sequences available on GenBank, we found that there are two different strains of chytrid in the observed NH amphibians. These strains are similar to strains noted previously in New England, but exhibit unique point mutations and in one case, a deletion. These variations could affect the impact that Bd has on amphibians in this region, and therefore could contribute to a better understanding of the variation in strains of chytrid and how they impact amphibian populations around the world. This study highlights the importance of monitoring efforts conducted at smaller, non-research institutions and we encourage other small institutions to take up similar monitoring efforts for Bd or other national or global conservation concerns.

ecology↗

Gene expression changes during female reproductive development in a colour polymorphic insect

Pleiotropy (multiple phenotypic effects of single genes) and epistasis (gene interaction) have key roles in the development of complex phenotypes, especially in polymorphic taxa. The development of discrete and heritable phenotypic polymorphisms often emerges from major-effect genes that interact with other loci and have pleiotropic effects on multiple traits. We quantified gene expression changes during ontogenetic colour development in a polymorphic insect (damselfly: Ischnura elegans), with three heritable female morphs, one being a male mimic. This female colour polymorphism is maintained by male mating harassment and sexual conflict. Using transcriptome sequencing and de novo assembly, we demonstrate that all three morphs downregulate gene expression during early colour development. The morphs become increasingly differentiated during sexual maturation and when developing adult colouration. These different ontogenetic trajectories arise because the male-mimic shows accelerated (heterochronic) development, compared to the other female morphs. Many loci with regulatory functions in reproductive development are differentially regulated in the male-mimic, including upstream and downstream regulators of ecdysone signalling and transcription factors potentially influencing sexual differentiation. Our results suggest that long-term sexual conflict does not only maintain this polymorphism, but has also modulated the evolution of gene expression profiles during colour development of these sympatric female morphs.

evolutionary biology↗