title: The challenge of evolving stable polyploidy: could an increase in "crossover interference distance" play a central role?
abstract: Whole genome duplication is a prominent feature of many highly evolved organisms, especially plants. When duplications occur within species, they yield genomes comprising multiple identical or very similar copies of each chromosome ("autopolyploids"). Such genomes face special challenges during meiosis, the specialized cellular program that underlies gamete formation for sexual reproduction. Comparisons between newly formed (neo)-autotetraploids and fully evolved autotetraploids suggest that these challenges are solved by specific restrictions on the positions of crossover recombination events and, thus, the positions of chiasmata, which govern the segregation of homologs at the first meiotic division. We propose that a critical feature in the evolution of these more effective chiasma patterns is an increase in the effective distance of meiotic crossover interference, which plays a central role in crossover positioning. We discuss the findings in several organisms, including the recent identification of relevant genes in Arabidopsis arenosa, that support this hypothesis.
authors.affiliation: Department of Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Colney, Norwich, NR4 7UH, UK.
authors.forename: Kirsten
authors.initials: K
authors.lastname: Bomblies
authors.affiliation: The Red House, St. David's Street, Presteigne, Powys (Wales), LD8 2BP, UK.
authors.forename: Gareth
authors.initials: G
authors.lastname: Jones
authors.affiliation: School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK.
authors.forename: Chris
authors.initials: C
authors.lastname: Franklin
authors.affiliation: Institut de Génétique et Microbiologie, I2BC, Université Paris-Sud, Orsay, France.
authors.forename: Denise
authors.initials: D
authors.lastname: Zickler
authors.affiliation: Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA. kleckner@fas.harvard.edu.
authors.forename: Nancy
authors.initials: N
authors.lastname: Kleckner
mesh_terms: D032461:Chromosomes, Plant / Q000235:genetics* / Q000378:metabolism; D003434:Crossing Over, Genetic; D019143:Evolution, Molecular; D008540:Meiosis; D010944:Plants / Q000235:genetics* / Q000378:metabolism; D011123:Polyploidy
keywords: Chiasmata; Crossover interference; Homologous chromosomes; Meiosis; Polyploidy; Recombination