Vol 4, No 4 (2006)

Homeodomain-containing transcription factors are the important regulators of multicellular organism's development. Plant transcription factors WOX and KNOX play the key role in meristem maintenance, controlling cell proliferation and preventing differentiation. The precise mechanism of WOX and KNOX action hasn't been well studied, however these transcription factors were shown to play the important role in plant hormones homeostasis, cytokinins in particular. Plant transcription factors of KNOX group demonstrate the similarities in structure and are supposed have the common origin with animal transcription factors of MEIS group. This review describes WOX and KNOX transcription factor families, their interaction with plant hormones. The role of homeodomain-containing transcription factors in plant and animal tumor formation is discussed.

GR-TRRd section of TRRd database accumulates the largest out of currently published samples of nucleotide sequences that are experimentally proved to bind glucocorticoid hormone receptor (GR). This sample consists of 160 glucocorticiod receptor binding sites (GRbss) from vertebrate genes controlled by glucocorticoids. analysis of the sample has shown that the structure of only half of GRbss (54%) corresponds to traditional viewpoint about structural organization of glucocorticoid response element (GRE) as an inverted repeat of hexameric half-site sequence TGTTCT. 40% of GRbss contain only hexameric half-site. Notably, there exist experimental evidence about participation of most of these GRbss in glucocorticoid regulation. as a result of increasing the number of sequences in the sample of GRbss, we have specified the consensus of sites organized in a form of inverted repeat (palindromic GREs). On the basis of literature data several possible mechanisms of action of noncanonical GRbss containing hexameric half-sites in glucocorticoid induction are proposed.

The publication is the 2-nd and the last part of the review analyzing modern trends of the researches in micronuclear test on human blood lymphocytes, cultivated with cytochalasin B. using data of literature and own results the opportunities of application of the test for study association between parameters of genome instability and genetic polymorphism, adaptive response to gamma-irradiation and emotional stress expression are considered. The analysis of additional capability of the test - frequencies of cells with nuclear buds and nucleoplasmic bridge are presents. Finally, results of the international researches on harmonization of the data of the test and guidelines for evaluation genotoxicity of chemical compounds in vitro are described.