Location: Animal Parasitic Diseases LaboratoryTitle: The genetics of Trichinella populations: a study in contrasts
Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 8/14/2020
Publication Date: 7/26/2021
Citation: Rosenthal, B.M., Bilska-Zajac, E., Thompson, P.C. 2021. The genetics of Trichinella populations: a study in contrasts. In: Bruschi, Fabrizio, editor. Trichinella and Trichinellosis. London, UK: Elsevier Academic Press. 25-34.
Technical Abstract: Population geneticists seek to define: • How much variation populations harbor. • How extensively populations differ from one another. • Whether species, genotypes, populations represent stably distinct reproductive units. The processes governing those patterns include: • Historical events that limited or accelerated variability’s accumulation. • Ongoing processes limiting or accelerating variability’s accumulation. • Population subdivision. • Genes flow among population subdivisions. For species of Trichinella, such analyses bear on practical questions such as: • How to trace outbreaks. • How to recognize and diagnose species. Other chapters in this book address insights that flow from studies of Trichinella evolution, systematics, taxonomy, and genomics. Here, we avoid undue repetition. Instead, we focus on settled and outstanding questions in Trichinella population genetics (referring the reader elsewhere for fuller explanation of the genetic and phylogenetic tools that serve as the foundation). Our present focus examines how much variation parasite populations harbor, and how distinct those populations have become. Below, we address four basic themes: 1. Species of Trichinella harbor distinct levels of genetic variability, reflecting contrasting histories. 2. Related species of Trichinella maintain distinctions despite occasional gene flow among them. 3. Extreme inbreeding in Trichinella typically engenders highly uniform infections. 4. Work remains to establish efficient, robust tools for outbreak tracing. 5. Population genetics sheds light on the origins of current challenges.