The evolutionary genomics of sexual recombination

  • Blaxter, Mark (Principal Investigator)
  • Lunt, David (Researcher)

Project Details

Description

This project, joint with the University of Hull (Dr David Lunt) will explore the effects on genomes of the mode of reproduction, using Meloidogyne plant parasitic nematodes as a model.
The overall aim of this project is sequence the genomes of diverse Root Knot Nematodes to allow us to test the influence of
breeding system and meiosis on genome content and diversity.
-Objective 1: Generate genome sequences across the phylogenetic diversity of RKN. Complete sequences of the genomes
of apomictic, automictic and amphimictic species will be generated, assembled and annotated using our established and
tested protocols.
-Objective 2: Characterize the effect of organismal breeding system on abundance, diversity and distribution of
transposable elements. Comparative genomic data for amphimicts, automicts, and apomicts will allow us to determine the
change in TE abundance, distribution and diversity in these breeding systems and relate this to existing predictions.
-Objective 3: Test for adaptive evolution of genes and gene families. We will use a statistical birth and death model of gene
family evolution to test the hypothesis of gene family constancy across a phylogenetic framework, and test sequence based
signatures of adaptive evolution and relate these to loci involved in either reproduction or plant-parasite interactions.

Layman's description

The puzzling predominance of sexual reproduction amongst animals has been repeatedly identified as one of the major
outstanding questions in biology and has received an enormous amount of study. Meiotic recombination is one of the
fundamental forces of evolution and plays a very significant role in both generating and mixing the genetic diversity present
in sexual organisms. Recombination is also suggested to be instrumental in shaping the content of eukaryotic genomes.
Here we propose to study the role of breeding system and recombination in shaping the content and diversity of animal
genomes using an exceptionally powerful natural system- the Root Knot Nematodes. We will, for the first time, be able to
take a comparative genomic view of radically different reproductive modes in a phylogenetic design. Together these studies
will give us a novel and powerful understanding of the role sexual reproduction plays in shaping genome content.

Key findings

The genome of Meloidofyne floridensis has need sequenced and assembled, and the data are being written up for publication.
These data suggest a very complex pattern of hybrid speciation in Meloidogyne, which has significant implications for control and identification.
StatusFinished
Effective start/end date1/09/1229/02/16

Funding

  • NERC: £427,540.00