Vol 8, No 4 (2010)


What do we know about variability?

Inge-Vechtomov S.G.


Contemporary phenomenological classification of variability types meets lots of contradictions. There is a single group of “mutations”: gene, chromosomal, genomic ones, which originate through different mechanisms. Ontogenetic variability puts even more questions because it embraces: modifications (regulation of gene expression), genetic variations (mutations and recombination) and epigenetic variations (and inheritance) in addition, with no clear criterions of the latter ones definition so far. Modifications and heritable variations are appeared to be closer to each other then we suspected before. An alternative classification of variability may be proposed basing upon template principle in biology. There is no direct correspondence between mechanisms and phenomenology of variation. It is a witness of a newparadigm coming in biological variability understanding.
Ecological genetics. 2010;8(4):4-9
pages 4-9 views

Epigenes — overgenes level hereditary units

Tchuraev R.N.


The theoretical and experimental aspects concept of epigenes are considered. In epigenes part of the heritable information is preserved, coded and trasmitted in generations out of the primary structure of genomic DNA. The behaviour under crosses simples modelic epigenes is demonstrated. The variants of molecular-genetics mechanisms of epigenes and original results of experimental construction artificials epigenes by methods gene-engenering are presented. The ontogenetic and phylogenetic roles of epigene systems are discussed. It has been shown, that even simplest epigene systems can provide key events of ontogeny. The epigenes systems can provide non-Darwinian evolutionary strategy by means of “remember” relatively unsuccesful muves of evolution and preservation reserved variants of ontogeny.
Ecological genetics. 2010;8(4):17-24
pages 17-24 views

Epigenetics of ecological niches

Tikhonovich I.A., Provorov N.A.


The development of symbioses ensures formation of the super-organism systems for heredity (symbiogenomes) which represent the products of joint adaptations of partners towards an unfavorable environment. Using the examples of symbioses which enable plants and microorganisms to cooperatively overcome the limitations in the major biogenic elements (C, N, P) or impacts of the biotic and abiotic stresses we demonstrate that symbiosis involves not only the de novo formation (epigenesis) by plant of the ecological niches for hosting the microsymbionts, but also the reorganizations of relevant genetic systems in accordance to the partners’ genotypes and environmental conditions. A possibility to address the ongoing processes in terms of epigenetics is evident when the microsymbionts occurring in the novel niches are included into the host reproduction cycle ensuring a stable maintenance of novel adaptation in the next generations suggesting that the newly formed symbiogenome have acquired the properties of a system for inheritance of the newly acquired adaptive traits.
Ecological genetics. 2010;8(4):30-38
pages 30-38 views

Genetics and epigenetics of syntropic diseases

Gorbunova V.N.


 The genetic components are involved in aetiology of the common human diseases. For most of them it is significant the phenomenon of syntropies — nonrandom combination of different diseases in the same patients. Three methodic approaches have been successfully used for the identification of genetic factors predisposed to the common human diseases: linkage analysis, candidate gene association studies (GASs) and genome-wide association scans (GWASs). The structural features of the many genes make a small but significant contribution to the overall risk of common diseases. Syntropy of related diseases is determined of having of share in disease pathogenesis the functional polymorphisms of genes controlling the same metabolic pathways. Nonrandom combination of different diseases in the same patients is determined of common epigenetic mechanisms involved in expression control of different «gene nets» disorder.
Ecological genetics. 2010;8(4):39-43
pages 39-43 views

Protein inheritance and regulation of gene expression in yeast

Mironova L.N.


Prions of lower eukaryotes are genetic determinants of protein nature. Last years are marked by rapid development of the conception of prion inheritance. The list of yeast proteins, which have been shown to exist in the prion form in vivo, and phenotypic manifestation of prions provide good reason to believe that protein prionization may represent epigenetic mechanism regulating adaptability of a single cell and cellular population to environmental conditions.
Ecological genetics. 2010;8(4):10-16
pages 10-16 views

Genetics or epigenetics? A peculiar case from the ciliate life

Yudin A.L.


Inheritance of three mating types (MTs) in the ciliate Dileptus anser is described. When reproduced vegetatively, clones of dilepti retain their mating type invariably. In sexual generations (at crosses) the character behaves as controlled by one locus with three alleles in it, manifesting serial dominance. In other words, the character seems to be under the direct genic control. However, after treatment with Actinomycin D, ciliates from clones which stably express this or that MT, become destabilized and start to express in turn all three MTs. It suggests that actually MT of such a clone results from stable epigenetic differentiation of a complex, multipotential locus.
Ecological genetics. 2010;8(4):25-29
pages 25-29 views

Epigenetical mechanisms of susceptibility to complex human diseases

Patkin E.L., Quinn J.


Contemporary data concerned an input of epigenetical mechanisms into an etiology and susceptibility to complex human diseases are critically analyzed. The special attention is attended to a specific role of simple tandem DNA repeats, the crucial role of developmental epigenetics in these processes. Patterns of mitotic and intergenerational inheritance of epigenetical modifications are considered.
Ecological genetics. 2010;8(4):44-56
pages 44-56 views

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