Publications by authors named "Pascal Angst"
Two important characteristics of metapopulations are extinction-(re)colonization dynamics and gene flow between subpopulations. These processes can cause strong shifts in genome-wide allele frequencies that are generally not observed in "classical" (large, stable, and panmictic) populations. Subpopulations founded by one or a few individuals, the so-called propagule model, are initially expected to show intermediate allele frequencies at polymorphic sites until natural selection and genetic drift drive allele frequencies toward a mutation-selection-drift equilibrium characterized by a negative exponential-like distribution of the site frequency spectrum.
View Article and Find Full Text PDFCrabs are a large subtaxon of the Arthropoda, the most diverse and species-rich metazoan group. Several outstanding questions remain regarding crab diversification, including about the genomic capacitors of physiological and morphological adaptation, that cannot be answered with available genomic resources. Physiologically and ecologically diverse Anomuran porcelain crabs offer a valuable model for investigating these questions and hence genomic resources of these crabs would be particularly useful.
View Article and Find Full Text PDFMicrosporidia are intracellular parasitic fungi whose genomes rank among the smallest of all known eukaryotes. A number of outstanding questions remain concerning the evolution of their large-scale variation in genome architecture, responsible for genome size variation of more than an order of magnitude. This genome report presents the first near-chromosomal assembly of a large-genome microsporidium, Hamiltosporidium tvaerminnensis.
View Article and Find Full Text PDFArticle Synopsis
- The study investigates the genomic diversity of the microsporidian parasite Ordospora colligata, emphasizing the role of evolutionary processes like phylogeography and natural selection in shaping this diversity.
- Results reveal a close phylogeographic relationship between O. colligata and its host, Daphnia magna, indicating a long-term relationship and adaptations to colder environments as opposed to other related parasites.
- The research also highlights the identification of regions under selection pressure and provides insights into the evolution of one of the smallest known eukaryotic genomes, illustrating how various factors contribute to the genomic variation of obligate parasites.
Article Synopsis
- The study investigates how extinction and recolonization in habitat patches affect the evolution of metapopulations, specifically comparing them to larger, stable populations.* -
- Using whole-genome pool-sequencing on 60 subpopulations of Daphnia magna, researchers found that metapopulations show lower genetic diversity and higher differentiation, supporting the propagule model which states that colonization leads to genetic bottlenecks.* -
- The results indicate that younger and more isolated subpopulations experience reduced effective population sizes and genetic drift, revealing that the evolutionary dynamics of metapopulations differ significantly from those of larger, stable populations.*
Article Synopsis
- The study explores how genomic diversity in the microsporidium Hamiltosporidium, a parasite of the crustacean Daphnia magna, can shed light on its ecology and evolutionary history.
- Researchers analyzed genomic samples from 18 populations across Eurasia, focusing on factors like modes of reproduction, transmission, and geography to understand their effect on genetic variation and population structure.
- Findings revealed two main parasite lineages, a lack of alignment with host lineages, and suggested a recent spread of the parasite influenced by changes in reproduction and transmission methods, highlighting broader patterns seen in other parasite species.