Turning Meiosis into Mitosis

Citation: Isabelle d'Erfurth, Sylvie Jolivet, Nicole Froger, Olivier Catrice, Maria Novatchkova, Raphaël Mercier (2009/06) Turning Meiosis into Mitosis. PLoS Biol (Volume 7) (RSS)
DOI (original publisher): 10.1371/journal.pbio.1000124
Semantic Scholar (metadata): 10.1371/journal.pbio.1000124
Sci-Hub (fulltext): 10.1371/journal.pbio.1000124
Internet Archive Scholar (search for fulltext): Turning Meiosis into Mitosis
Download: http://dx.doi.org/10.1371/journal.pbio.1000124
Tagged: meiosis (RSS), mitosis (RSS), asexual reproduction (RSS), biology (RSS), cell division (RSS)

Summary

Apomixis, or asexual clonal reproduction through seeds, is of immense interest due to its potential application in agriculture. One key element of apomixis is apomeiosis, a deregulation of meiosis that results in a mitotic-like division. We isolated and characterised a novel gene that is directly involved in controlling entry into the second meiotic division. By combining a mutation in this gene with two others that affect key meiotic processes, we created a genotype called MiMe in which meiosis is totally replaced by mitosis. The obtained plants produce functional diploid gametes that are genetically identical to their mother. The creation of the MiMe genotype and apomeiosis phenotype is an important step towards understanding and engineering apomixis.

Author Summary

In the life cycle of sexual organisms, a specialized cell division—meiosis—reduces the number of chromosomes from two sets (2n, diploid) to one set (n, haploid), while fertilization restores the original chromosome number. In contrast, mitosis produces two identical daughter cells. Basically, three features distinguish meiosis from mitosis. Meiosis has:

(i) a succession of two rounds of division following a single replication,

(ii) recombination, and

(iii) co-segregation of sister chromatids at the first division.

In this study, we identified a gene that controls one of these three features—entry into the second meiotic division—in the sexual plant Arabidopsis thaliana. By combining a mutation in this gene with two other mutations—one that eliminates recombination and another that modifies chromatid segregation—we created a genotype (called MiMe for mitosis instead of meiosis) in which meiosis is totally replaced by mitosis. As a consequence, MiMe plants produced diploid male and female gametes that are genetically identical to their parent, and ploidy doubles at each generation. The replacement of meiosis by mitosis is a key component of apomixis, or clonal reproduction through seeds, which has potential revolutionary application in crop improvement.

This was published in an open access journal.