| Autor: |
Buriev ZT; Center of Genomic Technologies, Institute of Genetics and Plant Experimental Biology, Academy of Sciences of Uzbekistan, Yuqori Yuz, Qibray Region, Tashkent 111226, Uzbekistan., Saha S, Shermatov SE, Jenkins JN, Abdukarimov A, Stelly DM, Abdurakhmonov IY |
| Jazyk: |
angličtina |
| Zdroj: |
TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik [Theor Appl Genet] 2011 Dec; Vol. 123 (8), pp. 1359-73. Date of Electronic Publication: 2011 Aug 18. |
| DOI: |
10.1007/s00122-011-1672-y |
| Abstrakt: |
The Gossypium MIC-3 (Meloidogyne Induced Cotton-3) gene family is of great interest for molecular evolutionary studies because of its uniqueness to Gossypium species, multi-gene content, clustered localization, and root-knot nematode resistance-associated features. Molecular evolution of the MIC-3 gene family was studied in 15 tetraploid and diploid Gossypium genotypes that collectively represent seven phylogenetically distinct genomes. Synonymous (d(S)) and non-synonymous (d(N)) nucleotide substitution rates suggest that the second of the two exons of the MIC-3 genes has been under strong positive selection pressure, while the first exon has been under strong purifying selection to preserve function. Based on nucleotide substitution rates, we conclude that MIC-3 genes are evolving by a birth-and-death process and that a 'gene amplification' mechanism has helped to retain all duplicate copies, which best fits with the "bait and switch" model of R-gene evolution. The data indicate MIC-3 gene duplication events occurred at various rates, once per 1 million years (MY) in the allotetraploids, once per ~2 MY in the A/F genome clade, and once per ~8 MY in the D-genome clade. Variations in the MIC-3 gene family seem to reflect evolutionary selection for increased functional stability, while also expanding the capacity to develop novel "switch" pockets for responding to diverse pests and pathogens. Such evolutionary roles are congruent with the hypothesis that members of this unique resistance gene family provide fitness advantages in Gossypium. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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