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211.
Hamster X fox somatic cell hybrids segregating individual fox chromosomes in different combinations were used to assign seven structural loci to fox chromosomes. The gene for ME1 was mapped on the VFU1 chromosome, the genes for ADK and PP being located on the VFU4 chromosome. The gene for GSR was assigned to the VFU7 chromosome and the genes for MPI and COT1 were assigned to the VFU15 chromosome. Localization of these genes enhances the established fox genetic map and extends the known syntenic homologies between the fox and other mammalian. The comparison of data on gene mapping has provided basis for suggestion that there are significant differences in rates of karyotypic evolution in many mammalian taxa. 相似文献
212.
Hypothesis: For any one time and place a ‘functional signature’ can be derived for a sample of herbaceous vegetation in a way that concisely represents the balance between the different clusters of functional attributes that are present among component species. Methods: We developed a spreadsheet‐based tool for calculating functional signatures within the context of the C‐S‐R system of plant functional types. We used the tool to calculate and compare signatures for specimen British vegetation samples which differed in management regime and location in time. Conclusion: The integrative power of the ‘C‐S‐R signature’ is useful in comparative studies involving widely differing samples. Movements in the signature can be used to indicate degree of resistance, resilience, eutrophication and dereliction. Systems of plant functional types other than C‐S‐R might also be approached in this way. Availability: The tool can be downloaded free of charge from the first author's web pages or from the journal's electronic archive. 相似文献
213.
O.?V.?NakonechnayaEmail author V.?S.?Sidorenko O.?G.?Koren’ S.?V.?Nesterova Yu.?N.?Zhuravlev 《Biology Bulletin》2008,35(5):459-465
An analysis of pollination system in Aristolochia manshuriensis has shown that flower structure in this species is strictly adapted to cross-pollination, but the possibility of an autogamous or geitonogamous type of self-pollination with the involvement of insects is not excluded. The flowers of A. manshuriensis are most frequently visited by flies of the family Anthomyiidae, which markedly contribute to their pollination. Males account for 65% of pollinator insects collected from the flowers. 相似文献
214.
The survival of transgenic mouse embryos was studied as a function of the transgene structure. The data obtained indicate that the introduction of a chromosomal DNA fragment providing for the anchoring of interphase chromosomes on the nuclear envelope increases the efficiency of transgenesis in mice threefold due to their increased viability. 相似文献
215.
E N Makhina G F Nesterova A V Grishin 《Molekuliarnaia genetika, mikrobiologiia i virusologiia》1985,(5):28-31
Spheroplasts of Hansenula polymorpha strain deficient in 2-isopropylmalate dehydrogenase have been shown to be transformed by the DNA of a hybrid plasmid pHRI, carrying the LEU2 gene from S. cerevisiae and 2.0 kilobase HindIII fragment of H. polymorpha genomic DNA. The frequency of transformants has reached 10(3) per 1 microgram of transforming DNA. Plasmid pHRI is maintained in transformants as an autonomous circular DNA molecule and is inherited by 1-2% fraction of cells from the population growing under the selective conditions. Transformation takes place under the same conditions that are required for spheroplast fusion. Thus, H. polymorpha becomes one more species of yeast susceptible to hybrid plasmid-mediated gene transfer in the process of DNA transformation. 相似文献
216.
Rubtsov NB Rubtsova NV Anopriyenko OV Karamysheva TV Shevchenko AI Mazurok NA Nesterova TB Zakian SM 《Cytogenetic and genome research》2002,99(1-4):323-329
Comparative chromosomal analysis is a powerful tool in the investigation of the mechanisms of chromosomal evolution. The accuracy of the analysis depends on the availability of region-specific markers to follow the fate of the particular chromosomal region through the evolution of species. We have assigned 12 unique sequences to the euchromatic part of the vole X chromosome, which serve as reliable markers of chromosomal segments. Together with region-specific libraries and GTG banding, these markers allow us to delineate the homologous regions of the X chromosomes in five species of the genus Microtus. We found that X chromosomes of these species differ by numerous rearrangements and all rearrangements are clustered at specific breakpoints. Moreover, these breakpoints were found to colocalise with repetitive and/or duplicated DNA sequences. We suggest that clusters of repeated and/or duplicated DNA sequences have played a crucial role in the formation of rearrangement hot spots during evolution of the X chromosome in the subgenus Microtus. 相似文献
217.
Onishchenko GG Moskvitina EA Kologorov AI Zyiatdinov KSh Morozov VV Pigalova NV Ziatdinov VB Bugrova EP Karnaukhov IG Gorlovskaia EV Sidimirova GM Savitskaia TA Iaminova VM Kamitova OM Shakurova LR Shagivaleeva SKh Galiliva GKh Kazakova ES Korolev IuS Nesterova DF Chernysheva AV Iumagulova EF Iantykova IuN 《Zhurnal mikrobiologii, epidemiologii, i immunobiologii》2002,(2):17-22
Data on emergent epidemiological analysis of the cholera outbreak in Kazan are presented. A version of the cholera focus emergence was confirmed, namely water route of transmission as a result of bathing in a water reservoir where sewage waters had penetrated. The outbreak had local and acute character. The complex of cholera control interventions aimed at localization and liquidation of the focus proved to be effective. 相似文献
218.
Polycomb group proteins Ring1A/B link ubiquitylation of histone H2A to heritable gene silencing and X inactivation 总被引:8,自引:0,他引:8
de Napoles M Mermoud JE Wakao R Tang YA Endoh M Appanah R Nesterova TB Silva J Otte AP Vidal M Koseki H Brockdorff N 《Developmental cell》2004,7(5):663-676
In many higher organisms, 5%-15% of histone H2A is ubiquitylated at lysine 119 (uH2A). The function of this modification and the factors involved in its establishment, however, are unknown. Here we demonstrate that uH2A occurs on the inactive X chromosome in female mammals and that this correlates with recruitment of Polycomb group (PcG) proteins belonging to Polycomb repressor complex 1 (PRC1). Based on our observations, we tested the role of the PRC1 protein Ring1B and its closely related homolog Ring1A in H2A ubiquitylation. Analysis of Ring1B null embryonic stem (ES) cells revealed extensive depletion of global uH2A levels. On the inactive X chromosome, uH2A was maintained in Ring1A or Ring1B null cells, but not in double knockout cells, demonstrating an overlapping function for these proteins in development. These observations link H2A ubiquitylation, X inactivation, and PRC1 PcG function, suggesting an unanticipated and novel mechanism for chromatin-mediated heritable gene silencing. 相似文献
219.
Krikunova N. I. Minaicheva L. I. Nazarenko L. P. Tadinova V. N. Nesterova V. V. Fadyushina S. V. Shapran N. V. 《Russian Journal of Genetics》2004,40(8):932-937
A retrospective epidemiological study has been performed using the data from healthcare institutions of the city of Gorno-Altaisk, Altai Republic, Russia for the period from 1983 to 2001. Congenital malformations (CMFs) have been studied in newborns, infants that died at ages under one year, and fetuses after 22 weeks of gestation. The most frequent malformations are those of the musculoskeletal and cardiovascular systems and multiple malformations, which account for 37.68, 18.22, and 8.9% of all congenital malformations, respectively. Their frequencies are 7.38, 3.57, and 1.74, respectively. The frequency of congenital malformations subject to registration by the national system of CMF monitoring of the Russian Federation (21 malformation forms) is 6.08 per 1000 births and varies from 8.59 to 21.24. The frequency of the Down syndrome is 0.93 per 1000 births; it did not vary significantly during the period studied. The frequency of limb reduction deformities in the urban population of Altai Republic (0.32 per 1000 births) is higher than in other Siberian regions, including the cities of Kyzyl (Tyva Republic) and Tomsk and the Nyurba and Ust-Aldan uluses of Sakha Republic (Yakutia) 相似文献
220.
The role of putrescine in the adaptive response of Escherichia coli grown aerobically in synthetic M9 medium with glucose to the H2O2-induced oxidative stress was studied. Under oxidative stress, the expression of the single-copy reporter gene fusions oxyR::lacZ and katG::lacZ was found to undergo biphasic changes, which were most pronounced in glucose-starved E. coli cells. The concentration-dependent activating effect of putrescine on the expression of the oxyR regulon genes was maximum when the oxyR gene was inhibited by high concentrations of hydrogen peroxide. 相似文献