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31.
32.
Zhimulev IF Beliaeva ES Andreeva EN Andreenkova NG Babenko VN Beliakin SN Boldyreva LV Brusentsova IV Demakov SA Zykov IA Kokoza EB Kolesnikova TD Maksimov DA Makulin IV Pindiurin AV Semeshin VF Khoroshko VA 《Genetika》2010,46(10):1405-1408
The modern concept of intercalary heterochromatin as polytene chromosome regions exhibiting a number of specific characteristics is formulated. DNA constituting these regions is replicated late in the S period; therefore, some strands of polytene chromosomes are underrepresented; i.e., they are underreplicated. Late-replicating regions account for about 7% of the genome; genes are located there in clusters of as many as 40. In general, the gene density in the clusters is substantially lower than in the main part of the genome. Late-replicating regions have an inactivating capacity: genes incorporated into these regions as parts of transposons are inactivated with a higher probability. These regions contain a specific protein SUUR affecting the rate of replication completion. 相似文献
33.
Anna H. Nagy Géza Erdös Natalia N. Beliaeva István Gyurján 《Molecular & general genetics : MGG》1981,184(2):314-317
Summary Acid phosphatase isoenzymes of Chlamydomonas reinhardii were investigated by isoelectric focusing in polyacrylamide gel systems. In this paper we describe in detail an original method for isoelectric focusing of acid phosphatases extracted from wildtype and acid phosphatase-lacking mutant algae, obtained from Laboratoire de Génetique of University of Liège. Three isoenzymes can be separated from the buffer-soluble components of these cells. An additional isoenzyme type can be visualized using the nonionic detergent NP40 as solubilizer. We conclude that these four isoenzymes are releated to the structural gene of the soluble constitutive acid phosphatase, which was shown by their appearance in P
2 and their total absence in mutant P
a. The pl values of soluble constitutive acid phosphatase isoenzymes range between pH 5.2 and 6.2. As a result of treatment with NP40 the extracts from both wild-type and mutant lines contain two additional active phosphatase forms which can be characterized by their high heat resistance and low pI values. These enzymes are fully active using either -naphthyl phosphate or different acetate esters as substrates. 相似文献
34.
Transpositions of MDG-1, MDG-3 and copia were detected as a result of crosses of the inbred maladaptive LA stock with laboratory stocks, in order to construct the genomes carrying different combinations of the LA or non-La chromosomal pairs. Changes of the mobile gene distributions were revealed in chromosomes of hybrid genotypes, as compared to parental chromosomal pairs. A trivial source of variability of chromosomal molecular structure ensured by crossing over was excluded by inversions which serve as suppressors of crossing over in corresponding crosses. Multiple transpositions of mobile genes in definite chromosomal sites were detected in genotypes carrying chromosomal pair 2 originated from the LA stock. No such transpositions were observed, when the pair 2 was substituted by the chromosome 2 originated from the Swedish-b line or in control crosses, where the LA stock was not involved. Both LA chromosomes 2 and 3 were shown to be the targets of transpositions. Comparison of hot spot transposition sites of MDG-1, as a result of crosses, with the earlier described rare events of spontaneous transpositions in the LA stock, coupled with its fitness increase, revealed that the hot spot sites were shared in both series of experiments. The data obtained show that transpositions of mobile genetic elements may change the genetic and molecular structure of the chromosome involved in crosses, in spite of suppression of crossing over by inversions usually suggested as a tool for keeping chromosomal genetic structure intact. 相似文献
35.
Emel'ianova LV Savina MV Beliaeva EA Braĭlovskaia IV 《Zhurnal evoliutsionno? biokhimii i fiziologii》2007,43(6):474-481
The work dealt with study of mitochondria in reversible metabolic suppression of hepatocytes of the river lamprey Lampetra fluviatilis in the course of prespawning starvation and of liver mitochondria of the common frog Rana temporaria during hibernation and activity. In winter the metabolic depression of lamprey hepatocytes, unlike that of frog hepatocytes, has been found to be due to deactivation of complex I of the electron transport mitochondrial chain, a low rate of NAD-dependent substrate oxidation, a low content of adenine nucleotide content, and a high degree of mitochondrial membrane permeability to H+ and other monovalent ions (KCl-, K+). The mitochondrial membrane permeability decreases in the presence of ethyleneglycoldiamineethyltetraacetic acid (EGTA), cyclosporine A (CsA), adenosine-5'-diphosphate (ADP), and Mg+. These facts indicate the presence in these mitochondria of the Ca2+ -dependent unspecific pore in the low-conductance state. Histological studies showed the lamprey and the frog to have principal differences in use of energy substrates at the period of metabolic depression. Lampreys utilize predominantly lipids, whereas frogs--glycogen. The clearly pronounces activation of lipid consumption is observed at the spring period before spawning and death of lamprey. Possible causes of metabolic depression are discussed as well as similarity and difference in behavior of mitochondria of cyclostomes and amphibians throughout metabolic depression and activity. 相似文献
36.
Laboratory mutator strain of Drosophila melanogaster is characterized by increased (up to 10(-3)-10(-4) frequency of spontaneous mutability. Mutations appear in premeiotic stages of gametes development. The majority of mutations were unstable (high frequencies of reversions, appearance of new mutations at the same and other loci, replicating instability). Localization of mobile elements mdg1, mdg2, mdg3, mdg4, copia and P element in X chromosomes of mutator individuals and its mutations y, ct, sbt was studied by hybridization in situ. In all strains P element was absent. The distribution of mdg1, mdg2, mdg3 and copia was identical in mutator strains and its derivatives, but distribution of mdg4 was different. The essential heterogeneity in localization of mdg4 and increased (up to 30-40) copy number in the mutator strain individuals was observed. The ability of single element mdg4 to autonomous transpositions was thus shown. 相似文献
37.
The influence of different concentrations of detergent Joy on the chromatin structure of Physarum polycephalum in the process of mitotic cycle was studied electronmicroscopically. The investigations showed that at Joy concentrations less than 0,01% a small part of nuclei disrupt and, as a rule, chromatin is insufficiently dispersed; at concentrations more than 0,1% the detergent may influence the chromatin structure of Physarum polycephalum. Based on the data obtained we consider that the optimal detergent concentrations that practically do not influence the chromatin structure and lead to disruption of the majority of nuclei and to the proper dispersion of chromatin is 0,1-0,01%. 相似文献
38.
Long-term chronic experiments with conditioning of monkeys and biophysical and pharmacological stimulation require monitoring somatic, emotional, and behavioral reactions. To form experimental groups, it is necessary to estimate baseline psychosomatic state of a monkey. We developed a method of monitoring the functional state of Macaca monkeys and scoring state parameters. With slight modification, this method may be applied to other monkey species. 相似文献
39.
The DNA sequences from Drosophila melanogaster early ecdysterone-inducible puff 2B have been located in 8 Drosophila species by in situ hybridization. The location site of the ecs, dor and swi genes in D. funebris, D. virilis, D. hydei, D. repleta, D. mercatorum, D. paranaensis is a puff on the telomeric and of X chromosome; in D. kanekoi it is the puff in distal part of X chromosome; and in D. pseudoobscura it is the puff in proximal portion of X chromosome. So, conservative organization of DNA sequences located in D. melanogaster 2B puff could be suggested. Dispersed distribution of some DNA segments from the region studied in D. hydei chromosomes was revealed. 相似文献
40.
Erofeev AI Aleksandrov AIu Beliaeva GS 《Zhurnal vysshe? nervno? deiatelnosti imeni I P Pavlova》2000,50(4):720-723
A new technique of training the primates to differentiate signals immediately during execution of the instrumental act (pushing the lever) was proposed. The technique makes it possible to study the processes of decision making during activation of the executive (motor) brain systems. 相似文献