Amazing World of Nematodes: 'Parasitic Success in Absence of Sex'

Would you like to learn more about nematodes--specifically, "Parasitic Success in the Absence of Sex: What Have We Learned from Nematode Genomes?"

French evolutionary biologist Etienne GJ Danchin will discuss that topic at a seminar on Monday, Nov. 20, hosted by the UC Davis Department of Entomology and Nematology.

The seminar is from 4:10 to 5 p.m. in Room 122 of Briggs Hall. It also will be on Zoom. The Zoom link:
https://ucdavis.zoom.us/j/95882849672 

Danchin, known for his work on genomics and adaptive molecular evolution, is with INRAE (French National Research Institute for Agriculture, Food and Environment) and is a senior scientist and scientific leader of the GAME team (Genomics and Adaptive Molecular Evolution) at ISA (Institut Sophia Agrobiotech), in Sophia-Antipolis, on the French Riviera.

"Root-knot nematodes are devastating plant parasites of worldwide importance. Interestingly, species that cause most damages reproduce entirely asexually," he writes in his abstract. "These nematodes are extremely polyphagous and have a wide geographic range. Theoretically, in the absence of sexual recombination animal species have lower adaptive potential and are predicted to undergo genome decay. To investigate how these species can be successful parasites on many hosts and in many places around the world, we have sequenced and analyzed their genomes. Out analysis confirmed these species are polyploid hybrids and the combination of several genotypes from different species might provide them with a general-purpose genotype. However, this does not explain how with a theoretically fixed genotype these species are able to overcome resistance genes or adapt to a new host. Therefore, we analyzed genomic variability across different populations and the possible mechanisms underlying genomic variations. In this presentation, I will provide an overview of our findings."

Etienne holds a doctorate in reproductive biology from the University of Paris (1980). He says on his website: "I am an evolutionary biologist working with genomes. I try to make biological sense of genomic singularities observed through comparative genomics. I have a special interest in plant parasites and I use bioinformatics as a tool to perform this research."

He lists his main research interests as: 

  • The impact of non tree-like evolution such as horizontal gene transfers and hybridization on species biology
  • Evolution and adaptation of animals in the absence of sexual reproduction and the underlying mechanisms
  • Genomic signatures of adaptation to a parasitic life-style

Seminar coordinator is Brian Johnson, associate professor, UC Davis Department of Entomology and Nematology. For Zoom technical issues, he may be reached at brnjohnson@ucdavis.edu. The list of seminars is posted here