[Genetic control of gametophytic apomixis: contemporary aspects]
Gerashchenkov, G.(Russian Academy of Sciences, Ufa (Russian Federation). Inst. of Biochemistry and Genetics. Ufa Scientific Centre)E-mail:[email protected] | Rozhnova, N.(Russian Academy of Sciences, Ufa (Russian Federation). Inst. of Biochemistry and Genetics. Ufa Scientific Centre)E-mail:[email protected]
The current state of knowledge about gametophytic apomixis, or asexual seed reproduction of flowering plants without both meiosis and fertilisation, is in the focus of this paper. The review accumulates the most important achievements in the genetics of apomixis, taking into account the transition from the investigation of "apomixis as a whole" to "the independent period", when the elements of apomixis (apomeiosis, parthenogenesis and endosperm formation) are perceived as independent objects of the analysis. Emphasis is placed on the illumination of the genetic basis of unusual phenomenon such as "seeds-without-sex-reproduction" in angiosperms. In the review, modern concepts of (1) mono- and polygenic inheritance of apomixis in different species, (2) epigenetic control, (3) genomic imprinting. (4) maternal effects, and (5) balance of chromosome number at endosperm are discussed. The genes conferring apomixis are not yet known, and this review highlights strategies of reverse genetics to detect the genes of interest. Strategies of engineering apomixis de novo such as (1) genetic complementation of meiotic mutations producing 2n gametes with "pollinator" effect producing haploids and (2) direct transgenesis of bacterial artificial chromosomes (BACs) from apomictic forms into sexual species to trace genes conferring apomixis are submitted.
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