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Vol 2, No 2 (2004)

Autonomous variability: phenomenon and possible mechanisms
Tikhodeyev O.N., Zhurina T.V.
The present paper is devoted to autonomous variation. It is shown that such type of variation is determined by entirely stochastic molecular processes. Therefore it can't be reduced to other types of variation that depend on some differences in genetic material, developmental stage or environmental influences. Certain examples of autonomous variation in plants and animals are observed. The possible mechanisms of this variation are discussed.
Ecological genetics. 2004;2(2):3-10
Photoperiodic regulation of reproductive and hormonal rhythms, and litter size in silver foxes (Vulpes vulpes): effects of selection for domestic behavior
Osadchuk L.V.
The silver fox is a strictly seasonal breeder, and photoperiod is the primary environmental cue that regulates reproduction in this species. The aim of the present paper is to study effects of long-term selection of silver foxes for domestic behaviour on photosensitivity in respect of oestrus activity, ovarian hormonal function and the litter size. Adult silver fox females from the commercial and selected population were exposed to artificial photoperiods (9.5L: 14.5D) from September until March in a specially equipped shed. The females of two behaviour types maintained in natural daylight served as a control. The experimental groups received illumination in two fractions, one of 7 and one of 2.5 hours duration. The 7-hour period was natural daylight from 10:00 to 17:00 and the additional light pulse was artificial illumination at night (00-02:30), in the morning (06:00-08:30) and in the evening (17:30-20:00). The results demonstrate that a light pulse at night can induce early oestrus and ovarian hormonal activity in anoestrus fox females and the effect was expressed in most extent in selected than in control females. Additionally, this photoperiod decreased dramatically the litter size in both behavioural groups. Photoperiods with morning and evening additional light pulse did not change the temporal pattern of the reproductive rhythm but the litter size was also decreased in control-combined group but not in selected one. All artificial photoperiods depressed the ovarian hormonal activity during follicular and luteal phases of the ovarian cycle and the group with the night additional light pulse had a most pronounced response. The data obtained suggested that behavior selection resulted in an alteration in the relationship between the endogenous reproductive rhythm and environmental photoperiod and increased resist-ibility to detrimental effects of artificial photoperiods on the litter size
Ecological genetics. 2004;2(2):11-21
Tendril-less2 (TI2) - a gene providing the pea Pisum sativum L with ability to climb
Berdnikov V.A., Gorel F.L.
After gamma-ray treatment of pea seeds, a mutation tendril-less2 (tl2) was obtained. In heterozygote, it transforms tendrils into a narrow leaflets, resembling an action of the classic mutation tl. In contrast to tl, the novel mutation, when homozygous, does not affect leaf development but supresses pigmentation of petals. It is suggested that both genes (Tl and TI2), responsible for transformation of leaves into an organ of climbing, have common origin from a gene controlling anthocyanine synthesis
Ecological genetics. 2004;2(2):22-28
Transfer of Sym-plasmids into symbiotically active and asymbiotic rhizobia strains: properties of recombinants and possible evolutionary consequences
Provorov N.A., Fokina I.G., Roumiantseva M.L., Simarov B.V.
Transfer of Sym-plasmids from the clover rhizobia to avirulent mutants of the same rhizobia species or of alfalfa rhizobia resulted in recombinants with a restored symbiotic activity. Transfer of these plasmids into the wild type isogenic strains lead to a decrease of their symbiotic activity. These data confirm the hypothesis on the crucial role of avirulent rhizobia strains in the transfer of Sym-plasmids which directs evolution of these bacteria
Ecological genetics. 2004;2(2):29-34
Analysis of stable chromosome aberrations, revealed with FISH-method in veterans of special risk troops
Vorobcova I.E., Lubimova N.E., Perova A.A., Semenov A.V.
The frequency of stable chromosomal aberrations, detected by FISH, was found to be significantly higher in group of persons undergone low-dose irradiation (Semipalatinsk, Novaya Zemlya, South Ural) as compared to age-matched control group. The age accumulation of a stable chromosome aberrations in an age range 45-76 years was more expressed in exposed group than in control one
Ecological genetics. 2004;2(2):35-40

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