Analytical Methodology of Meiosis in Autopolyploid and Allopolyploid

Abstract

Meiosis is the cellular process responsible for producing gametes withhalf the genetic content of the parent cells.Integral parts of the processin most diploid organismsinclude the recognition, pairing,synapsisand recombination of homologous chromosomes, which are pre-requisites for balanced segregation of half-bivalents during meiosis I. In polyploids, the presence ofmore than two sets of chromosomesadds to the basic meiotic program of theirdiploid progenitors the possibility of interactions between more than two chromosomes and the formation of multivalents, which hasimplications on chromosome segregations and fertility. The mode of how chromosomesbehave in meiosis in competitive situationshas been the aim of many studies in polyploid species, some of which are considered here. But polyploids are also of interest in the study of meiosis because some of them tolerate the loss of chromosome segments or complete chromosomes as well as the addition of chromosomes from related species. Deletions allow to assess the effect of specific chromosome segments on meioticbehaviour. Introgression lines are excellent materials to monitor the behaviour of a given chromosome in the genetic background of the recipient species.We focus on this approach hereas based on studies carried out inbread wheat, which is commonly used as amodel species for meiosis studies. In addition to highlight the relevance of the use of materials derived from polyploids in the study of meiosis,cytogenetics tools such as fluorescence in situhybridizationand the immunolabellingof proteins interacting with DNA, are also emphasized.