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Vol 7, No 2 (2009)
- Year: 2009
- Articles: 7
- URL: https://journal-vniispk.ru/ecolgenet/issue/view/296
- DOI: https://doi.org/10.17816/ecogen72
Articles
Cytoplasmic incompatability in Drosophila melanogaster due to different Wolbachia genotypes
Abstract
Wolbachia is an endosymbiont prevalent among different arthropoda and in some Nematoda species. The bacteria ads across the populations of host species via induction of reproductive abnormalities: cytoplasmic incompatability, parthenogenesis, feminization, and male killing. we estimated the level of cytoplasmic incompatability in Drosophila melanogaster caused by three most prevalent Wolbachia genotypes, namely wmel, wmelCS и wmelCS2. wmel and wmelCS genotypes were shown to cause mild cytoplasmic incompatibility (< 10 %), while wmelCS Wolbachia were unable to do so. Possible mechanisms of sustainability of Wolbachia in the populations of Drosophila melanogaster are discussed.
Ecological genetics. 2009;7(2):11-18
11-18
Symbiotic activity of the alfalfa rhizobia (Sinorhizobium meliloti) strains with the genetically modified transport of dicarboxylic acids
Abstract
Inactivation of genes involved in the dicarbyxylic acid transport in alfalfa rhizobia, Sinorhizobium meliloti (structural gene of succinate permease dctA and its transcriptional regulators dctBD, nifA, ntrA) resulted in the full or partial loss of N2-fixing activity while amplifications of these genes - in its improvement. It lead to the marked increases of N and C accumulation in alfalfa while its shoot mass was increased by a much lesser degree due to the incomplete N translocation from the roots. Factorial analysis suggested that dctABD amplification was important for improving the symbiotic efficiency in all trials while the effects of dctA, nifA and ntrA amplifications depend on the plant genotypes and growth conditions.
Ecological genetics. 2009;7(2):3-10
3-10
Polymorphism among Sinorhizobium meliloti isolates native to the origins of alfalfa diversity differed in soil-climate characteristics
Abstract
Sinorhizoboium meliloti populations native to the 4 distinct gene centers (GC) of alfalfa were explored toward the tolerance to salinity, cryptic plasmid profiles and symbiotic properties. The significant correlations detected among nodule (N) and trapped (T) isolates related to the similar or distinct populations. more than 60 % N- and 77 % T-isolates tolerant to 3,5 % NaCl; salt tolerant N-isolates formed effective symbiosis with Medicago sativa and M. truncatula significantly more often. Isolates native to the GC area next to aral Sea had possessed the reduced level of salt tolerance in comparison with the isolates originated from Central asian, North-Caucasian and Europe-Siberian GC; that, has related to adaptation processes, which have ensured their viability in extremely salted soils.
Ecological genetics. 2009;7(2):19-25
19-25
Evolutionary analysis of sequences expressed in tumors
Abstract
Earlier we have identified a new class of human genomic sequences expressed preferentially in tumors. Here we use a comparative genomics approach and conservation analysis to study evolutionary specificity of nine human tumor-specific sequences, described previously. Three sequences had originated in the primate lineage. The other three had mammalian orthologs, but conservation analysis has shown that these sequences evolved neutrally. Three sequences were conservative. These data confirm previously formulated hypothesis that evolutionarily new genes are expressed in tumors.
Ecological genetics. 2009;7(2):26-37
26-37
Problems of rational use of genetic resources of plants resistance to diseases
Abstract
The decision of a complex problem of rational use of plants genetic resources of resistance to diseases is based on principles of maintenance of a genetic diversity of resistance. The development of methodology of grain crops breeding with durable resistance to diseases is based on knowledge of evolutionary potential of most harmful pathogens and genetics of host-pathogen interactions. For molecular mapping of genes determined barley resistance to net blotch, spot blotch and scald double haploid barley populations were developed. Molecular mapping of genomes both plants and pathogens will promote the development of DNa- technologies in plant breeding.
Ecological genetics. 2009;7(2):38-43
38-43
Loss of allelic diversity in species of hybrid origin
Abstract
Species of hybrid origin support their population as a rule by cloning. Switching over of any bisexual organism to propagation by means of parthenogenesis, gynogenesis, androgenesis (or other kind of apomictic reproduction without regular recombination, which usually accompanies change of generations in bisexual species) leads to rapid decrease of genetic polymorphism. Long-term cloning transforms the polymorphic population or entire species into a mixture of only a few clones, composed of genetically identical individuals. owing to selection in favour of heterozygotes or due to hybrid origin, natural clonal populations commonly are of high heterozygosity. Selection, genotypic uniformity and high heterozygosity often give to clonal race or species selective advantages, but at the same time they inevitably result in loss of most of alleles. Inasmuch as new forms, reproductively isolated from parental species, are products of hybridization of only a small number of individuals, which succeed in overcome the interspecies barrier, the hybridization itself also plays role of a very narrow bottle neck. The well established opinion that recombination and allelic diversity are necessary conditions for successful evolution on the basis of gene frequency changes, comes now into contradiction with the available data concerning the polyploid and, probably, hybrid origin of many groups of flowering plants and vertebrate animals.
Ecological genetics. 2009;7(2):47-49
47-49
Allantoin and urate as the supressors of genotoxic effect of the ultraviolet irradiation with wavelength 300-400 nm
Abstract
Genotoxicity of ultraviolet radiation with wavelength 300-400 nm (sunlight uVR) is mediated by the generation of reactive oxygen species. The research which was carried out on the base of developed early bacterial model indicated the existence of uV-protecting activity of allantoin, formed from uric acid in organisms of all vertebrates except human and anthropoid apes. The uric acid which is the end-product of purine catabolism in the organism of anthropoid apes, does not possess statistically significant protective effect. Safety of allanoin makes it a perspective component of sunlight protectors.
Ecological genetics. 2009;7(2):44-46
44-46