RESUMO
The sy19 mutation, which impairs the homology of meiotic chromosome synapsis in rye, were mapped using a specially created F2 population by means of isozyme Acph 1 locus and microsatellite (SSR) markers. The sy19gene was localized in the chromosome 7R in the pericentromeric region of long armbased on the linked inheritance with the Acph 1 locus. The locus was linked with five rye SSR markers, with the Xrems 1234 locus being located closest to the sy19 gene (6.4 cM). The genetic map of the analyzed chromosome 7R region includes ten markers and the sy19 locus. A possible function of the Sy1 and Sy19 genes based on the data on comparative genomics is discussed.
Assuntos
Pareamento Cromossômico/genética , Cromossomos de Plantas/genética , Genes de Plantas , Meiose/genética , Repetições de Microssatélites/genética , Mutação , Secale/genética , Mapeamento Cromossômico/métodos , Loci Gênicos/fisiologia , Isoenzimas/genéticaRESUMO
The recessive spontaneous sy18 mutation with nonhomologous synapsis was mapped in rye. The sy18 gene was located in the centromeric region of chromosome 2R in relation to three rye SSR (simple sequence repeats) loci, i.e., Xrems1130, Xrems1203, and Xscm43, and one wheat SSR locus Xgwm132. The desynaptic sy18 gene is located in the interval between Xrems1130 and Xrems1203 markers at a distance of 0.5 cM and 3.1 cM, respectively. The possible evolutionary relationships of the mapped gene with homologous loci of the related species are discussed.
Assuntos
Cromossomos de Plantas , Genes de Plantas , Meiose/genética , Repetições de Microssatélites , Secale/genética , Centrômero , Mapeamento Cromossômico/métodos , Pareamento Cromossômico , MutaçãoRESUMO
Studies of phenotypical expression of synaptic mutations in combination with the localization of corresponding genes on a genetic map permit individual stages of the meiotic process to be differentiated. Two rye asynaptic genes, sy1 and sy9, were mapped with the use of microsatellite markers (SSR) in the pericentromeric regions of the long chromosome arms 7R and 2R, respectively. The sy9 gene cosegregated with two SSR markers Xscm43 and Xgwm132. The asynaptic gene sy1 was mapped within the interval between the isozyme locus Aat2 and two cosegregating loci Xrems1188 and Xrems1135 that are located at a distance of 0.4 cM proximally and 0.1 cM distally with respect to the gene lous. Possible evolutionary relationships of the mapped genes with homeological loci of the Triticeae species and more distant cereal species, such as maize and rice, are discussed.
Assuntos
Cromossomos de Plantas/genética , Evolução Molecular , Genes de Plantas/genética , Loci Gênicos/genética , Repetições de Microssatélites/genética , Secale/genética , Mapeamento Cromossômico , Grão Comestível/genética , Oryza/genética , Especificidade da Espécie , Zea mays/genéticaRESUMO
A collection of 68 cultivars of common wheat has been screened for leaf rust resistance genes with the use of molecular markers. Markers of genes Lr1, Lr9, Lr10, Lr19, Lr20, Lr21, Lr24, and Lr26 have been used. It has been suggested that allele Xgwm295 be used as a marker for identifying the Lr34 gene. The genes originating from Triticum aestivum L., as well as the Lr26 gene contained in rye translocation 1RS, are the most frequent. Genes originating from wild wheats were rarer in the cultivars studied.
Assuntos
Basidiomycota/patogenicidade , Genes de Plantas , Doenças das Plantas/genética , Triticum/genética , Primers do DNA , Marcadores Genéticos , Doenças das Plantas/microbiologia , Triticum/microbiologiaRESUMO
Probable relationship between modulation of gene expression by simple repeating sequences and competition capacity of the host was studied. (AC)20 repeat can both stimulate and inhibit the expression of chloramphenicol acetyl transferase gene expression in E. coli cells depending on this gene's position. Modulation of the gene expression by simple (AC)20 repeat and competitive capacity of bacteria containing this plasmid are closely related.