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971.
The dynamics of allele frequency of the carboxiesterase gene, the frequency of sex-linked lethal mutations, and recombination events in natural populations of Drosophila melanogaster from Odesa were studied. All studied estimates were shown to remain unchanged in June, July, and August during the 2009 collection season.  相似文献   
972.
The antimutagenic activities of the oils obtained from leaves and fruits of Fagus orientalis have been shown in experiments with spontaneous and mutagen- and ageing-induced variability. The aberrations of chromosomes in the meristematic cells of the Allium cepa L., Vicia faba L., Triticum aestivum L., and marrow cells of Vistar rats as well as Arabidopsis thaliana gene mutations have been mobilized as experimental tests.  相似文献   
973.
The distribution of alleles at the Lr34 locus associated with leaf rust resistance among winter common wheat (Triticum aestivum L.) cultivars of Ukrainian breeding was studied. Co-dominant molecular-genetic marker cssfr5 was used for detection of the allelic condition of the Lr34 locus. The cultivars with detected allele Lr34(+) were identified as potentially "resistant" and the cultivars in which detected allele Lr34(-) were identified as potentially "susceptible". The collection of the cultivars (81 ones), created in the main plant breeding centers of Ukraine was analyzed. The allele Lr34(+) was identified in 44% cultivars. Results were compared with the data about the distribution of the Lr34(+) in cultivars created in different countries.  相似文献   
974.
Transgenic plants were regenerated from Cichorium intybus L. hairy roots transformed with genes of tuberculosis antigenes ESAT6 and Ag85B or human interferon alpha2b. The plant regeneration was light-dependent and occurred on the media without growth regulators. The DNA PCR and RT-PCR analyses have shown the presence and expression both selective and target genes in all root lines and regenerated plants.  相似文献   
975.
Dispermic androgenesis was used to produce, for the first time, an androgenetic progeny of the Siberian sturgeon (Acipenser baerii) and the androgenetic nuclear cytoplasmic hybrids (Siberian sturgeon, A. baerii x Russian sturgeon, A. gueldenstaedtii) using cryopreserved sperm. Microsatellite DNA analysis confirmed exclusively paternal inheritance in the androgenetic progeny of Siberian sturgeon. Heterozygotes for certain microsatellite loci were detected among the androgenetic hybrids, thereby confirming a dispermic nature of androgenesis. According to the data of comparative morphological analysis, the obtained androgenetic hybrid, by the age of 15 months old, was completely identical to the paternal species. Both a female and a male were detected in the androgenetic sturgeon progenies, which is of interest for producing bisexual progenies via androgenesis. The data of this study confirm the feasibility of dispermic androgenesis using cryopreserved sperm to preserve and recover the gene pools of endangered sturgeon species.  相似文献   
976.
Living organisms well adapt themselves to changes in the environment and are robust to potential damage such as mutations. The epigenetic mechanism whereby the suppression of phenotypic variation is achieved has been dubbed canalization. This paper summarizes results of research that employed experimental and theoretical approaches to uncover the mechanisms of canalization of variation in expression of segmentation genes.  相似文献   
977.
Kavaĭ-ool UN  Ezhova TA 《Ontogenez》2011,42(2):151-158
A new mutant, fimbriata petioles (fip), of Arabidopsis thaliana was obtained by chemical mutagenesis. The mutant is characterized by unusual anomalies of floral organs. Clusters of very large cells formed in the distal region of sepals and petals, which created fringed edges of these organs. An analysis of the morphology of the floral organs and leaves of the fip as 1 double mutant revealed a complementary interaction of the ASYMMETRIC LEAVES1 (AS1) and FIMBRIATA PETIOLES (FIP) genes. It was assumed that the FIP gene, together with the AS1 gene, controls cell proliferation, preventing their premature entry into endocycle.  相似文献   
978.
Results are presented from studies of the possibility of using a thin metal foil for recyclable vacuum transmission lines with magnetic insulation in a conceptual fusion reactor based on high-voltage high-current electromagnetic generators. Numerical simulations and experiments in the Angara-5-1 facility were carried out to determine both the threshold for the explosion of a foil heated by a current pulse and the parameters of the plasma layer formed at the foil surface. It was found experimentally that an additional plasma current channel forms on the surface of a 120-μm stainless-steel foil at a linear current density of 0.25–0.5 MA/cm, which corresponds to a magnetic field of 0.3–0.6 MG. For the same conditions, one-dimensional computer simulations of the foil heating were performed in an MHD model by using a wide-range semiempirical equation of state for stainless steel. The calculated threshold for plasma generation on the foil surface is compared with the experimental data. The main parameters of the plasma layer are also calculated at linear current densities of 2–10 MA/cm, which far exceed the threshold current density. The plasma layer parameters as functions of the linear current density are determined for the case of an iron foil.  相似文献   
979.
Reactions of 277 neurones located in the brain pons dorsolateral portion were analised in staying awake and narcotized rats during immobility reflex, induced by the skin constriction on the neck dorsal surface. Got excited: fast adaptive tactile neurons (n = 32), interneurons (n = 42), and cells forming monosynaptic inputs to the parts of medulla oblongata, which inhibit the movements (n = 10). Were inhibited: somatosensory (n = 42), nociceptive (n = 24) and nonidentificated (n = 14) neurons. In some neurons charge characteristics were stable or slightly modified, namely: respiratory neurons (n = 16), cell group, having stable background firing (n = 72) and stimulating antidromically spontaneously silent ponto-medullar neurons (n = 22).  相似文献   
980.
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