Meiosis: Recombination and the Control of Cell Division
Meiosis is a key step in sexual reproduction.. It is required for the production of gametes, consequently fertility, and generates diversity by scrambling parental genotypes. Thus, it is central to plant genome evolution The last ten years have provided a
- PDF / 759,330 Bytes
- 16 Pages / 595.276 x 790.866 pts Page_size
- 84 Downloads / 174 Views
Meiosis: Recombination and the Control of Cell Division Eric Jenczewski, Raphael Mercier, Nicolas Macaisne, and Christine Me´zard
Contents
8.1
8.1
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
8.2 8.2.1 8.2.2 8.2.3 8.2.4
Meiotic Recombination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Initiation of Meiotic Recombination . . . . . . . . . . . . . . . . . . . . . . Meiotic DNA Double-Strand Break Repair . . . . . . . . . . . . . . . Crossover Distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Crossover Formation and Interference . . . . . . . . . . . . . . . . . . . .
8.3
Dynamics of Chromosomes, Chromatin Structure and Meiosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127
123 123 124 125 127
8.4 Meiotic COs in Polyploid Plants . . . . . . . . . . . . . . . . . . . . . . . . 129 8.4.1 Changes in CO Distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129 8.4.2 Genetic Control of CO Formation . . . . . . . . . . . . . . . . . . . . . . . . . 130 8.5
The Meiotic Cell Cycle in Plants . . . . . . . . . . . . . . . . . . . . . . . . 131
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133
C. Me´zard (*) Institut Jean-Pierre Bourgin, Institut National de Recherche Agronomique, route de Saint-Cyr, 78026 Versailles, cedex, France e-mail: [email protected] I.J. Leitch et al. (eds.), Plant Genome Diversity Volume 2, DOI 10.1007/978-3-7091-1160-4_8, # Springer-Verlag Wien 2013
Introduction
Meiosis is a key step in the reproduction of many species, halving ploidy levels to produce haploid gametes, which are then restored by fertilization. The reduction in ploidy in meiosis results from one cycle of replication followed by two cell divisions (Fig. 8.1). During the first division, which is very specific to meiosis, the homologous chromosomes segregate to opposite poles. The second division during which the sister chromatids separate, is a modified version of mitosis. Thus a diploid cell produces four haploid spores. However, depending on species-specific mechanisms for sporocyte maturation, it is possible that not all spores become gametes. For example, in Arabidopsis thaliana four spores are obtained from female meiosis but only one matures to produce an embryo sac containing an egg cell, while in male meiosis, all four spores give rise to pollen grains. During the first meiotic division, homologous chromosomes recombine producing mosaic chromosomes that are harmonious patchworks of the original genetic material contained in the meiocytes. The underlying molecular mechanisms for these recombination events are very well conserved among species even if each species has shown some specificity in regulation of the pathways or the molecular actors involved. Recombination is initiated by the formation of programmed DNA double st
Data Loading...
