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[A genetic analysis of variants of the human immunodeficiency virus type 1 (HIV-1) circulating among drug abusers in Moscow and Moscow Province].

The genetic analysis of the variants of human immunodeficiency virus of type 1 (HIV-1), circulating among drug addicts in Moscow and Moscow Province, has been carried out. The serological analysis of 122 blood specimens taken from HIV-infected drug addicts, residing in Moscow and 22 settlements of the Moscow region, has shown that in this region HIV-1 variant of subtype A spreads among drug addicts. These data have been confirmed by the results of the analysis of 44 specimens, made with the use of the method of the heteroduplex mobility assay for gene env. As revealed in this study, HIV-1 variants spreading at present among drug addicts in Moscow and the Moscow region are genetically related to viruses of subtype A, detected earlier in this group of risk in other regions of Russia, the Ukraine, Belarus and other countries of Eastern Europe.

Base Sequence↗

A cross-sectional behavioral genetic analysis of task persistence in the transition to middle childhood.

Task persistence, measured by a composite score of independent teacher, tester and observer reports, was examined using behavioral genetic analysis. Participants included 92 monozygotic and 137 same-sex dizygotic twin pairs in Kindergarten or 1st grade (4.3 to 7.9 years old). Task persistence was widely distributed, higher among older children, positively associated with standardized tests of cognitive performance and achievement, and negatively associated with parents', teachers' and observers' reports of behavioral problems. Cross-sectional analysis indicated a strong developmental shift from shared environment variance among younger children to additive genetic variance in older children.

Age Factors↗

Further considerations for behavior-genetic analysis of humans.

In this reply to Plomin and Foch (1985) we maintain that the five specific points we criticized in their behavior-genetic analysis of personality are still important (Haviland, McGuire, & Rothbaum, 1983). In addition, we briefly describe three relevant issues in experimental behavior-genetic studies as they apply to correlational behavior-genetic studies of human personality.

Genetics, Behavioral↗

[Founding and genetic analysis of Landrace x Lantang pig resource population for QTL mapping].

With F2 design, 16 Chinese Lantang sows crossbred with eight highly improved Landrace boars to establish a resource population including 40 F1 sows, eight F1 boars, and 232 F2 pigs. Genetic analysis of the resource population showed that the 32 performance traits displayed some degree of variation, and coefficients of variation of the majority of economic traits exceeded 10%. The variance component analysis revealed that the ratios of additive genetic variance to phenotypic variance of the majority of economic traits were high. Of the 22 microsatellite DNA markers, only 12 microsatellite DNA markers are polymorphisic in this populations. The average heterozygosity of these markers and PIC were 0.53 and 0.46 respectively. The results showed that these markers can provide enough information for QTL mapping. In conclusion,the F2 pigs were sufficiently segregated, and were capable of serving as a resource population for QTL mapping.

Animals↗

Genetic analysis of phenotypic variation for ectomycorrhiza formation in an interspecific F1 poplar full-sib family.

A plant's capability to develop ectomycorrhizal symbiosis is under the control of both genetic and environmental factors. In order to determine the roles played by these different factors, we have performed a quantitative genetic analysis of the ability of poplar trees to form ectomycorrhizas. Quantitative genetics were applied to an interspecific family of poplar for which the two parental genetic maps had already been described, and for which data analyses concerning fungal aggressors were obtained. Quantitative trait loci (QTL) related to ectomycorrhiza formation were identified and located in the genetic maps of the two parents. One QTL was located at a linkage group of the genetic map of Populus trichocarpa showing a high concentration of several QTL involved in the pathogenic interaction with the fungus Melampsora larici-populina, the causal agent of leaf rust.

Basidiomycota↗

[Genetic analysis of a polygenic system of a quantitative character after negative and positive selection. I. General characteristics of the polygenic system].

Genetic analysis of phenotypic expression of the quantitative character controlled by an oligogenic mutation radius incompletus (ri) and a polygenic system in Drosophila melanogaster was carried out. Flies from the control line riC and two contrasting selection lines, riSR (positive selection) and riSN (negative selection) were crossed to the wild-type line riN. Proximal and distal segments of the longitudinal wing vein were measured in F2 ri/ri homozygotes. RiC and riN lines were shown to carry sets of polygenes with equivalent phenotypic contribution while selection lines (riSP and riSN) had an excess of polygenes of positive and negative effect, respectively. Striking similarity in some features of the polygenic system and localization of mobile genetic elements in the chromosomes of the lines was demonstrated.

Animals↗

Molecular genetic analysis of the polymorphic apolipoprotein E in modern and ancient human DNA samples.

In this report, methodical bases for the molecular genetic analysis of the three common apolipoprotein E alleles APOE*2, APOE*3 and APOE*4 in DNA isolated from ancient human skeletal remains are described. Considering that ancient DNA target regions for amplification are generally quite small, the detection method is based on short amplification products in the range from 71 bp to 75 bp. The applicability of the modified method for APOE genotyping was examined in modern human DNA samples.

Apolipoproteins E↗

A quantitative genetic analysis of nuclear-cytoplasmic male sterility in structured populations of Silene vulgaris.

Gynodioecy, the coexistence of functionally female and hermaphroditic morphs within plant populations, often has a complicated genetic basis involving several cytoplasmic male-sterility factors and nuclear restorers. This complexity has made it difficult to study the genetics and evolution of gynodioecy in natural populations. We use a quantitative genetic analysis of crosses within and among populations of Silene vulgaris to partition genetic variance for sex expression into nuclear and cytoplasmic components. We also use mitochondrial markers to determine whether cytoplasmic effects on sex expression can be traced to mitochondrial variance. Cytoplasmic variation and epistatic interactions between nuclear and cytoplasmic loci accounted for a significant portion of the variation in sex expression among the crosses. Source population also accounted for a significant portion of the sex ratio variation. Crosses among populations greatly enhanced the dam (cytoplasmic) effect, indicating that most among-population variance was at cytoplasmic loci. This is supported by the large among-population variance in the frequency of mitochondrial haplotypes, which also accounted for a significant portion of the sex ratio variance in our data. We discuss the similarities between the population structure we observed at loci that influence sex expression and previous work on putatively neutral loci, as well as the implications this has for what mechanisms may create and maintain population structure at loci that are influenced by natural selection.

Cell Nucleus↗

Leaf-rust resistance in rye (Secale cereale L.). 2. Genetic analysis and mapping of resistance genes Pr3, Pr4, and Pr5.

Three dominant resistance genes, Pr3, Pr4, and Pr5, were identified by genetic analysis of resistance to leaf rust in rye (Puccinia recondita f. sp. secalis). Each of the three genes confers resistance to a broad scale of single-pustule isolates (SPIs), but differences could be observed for specific Pr gene/SPI combinations. Resistance conferred by the three genes was effective in both detached-leaf tests carried out on seedlings and in field tests of adult plants. Molecular marker analysis mapped Pr3 to the centromeric region of rye chromosome arm 1RS, whereas Pr4 and Pr5 were assigned to the centromeric region of 1RL. Chromosomal localization and reaction patterns to specific SPIs provide evidence that the three Pr genes represent distinct and novel leaf-rust resistance genes in rye. The contributions of these genes to resistance breeding in rye and wheat are discussed.

Base Sequence↗

Genetic analysis suggests functional interactions between the N- and C-terminal domains of the TetA(C) efflux pump encoded by pBR322.

Genetic analysis of the tetA(C) gene of pBR322 indicates the importance of two-cytoplasmic loops in the TetA(C) protein (P. McNicholas, I. Chopra, and D. M. Rothstein, J. Bacteriol. 174:7926-7933, 1992). In this study, we characterized second-site suppressor mutations that suggest a functional interaction between these two cytoplasmic regions of the protein.

Amino Acid Sequence↗

In vitro genetic analysis of the Tetrahymena self-splicing intron.

The availability of methods for the amplification of nucleic acid sequences allows the genetic analysis in vitro of the structural and functional properties of many nucleic acids. We have now developed an in vitro selection and amplification system, and used it to analyse the self-splicing Tetrahymena ribozyme. A much wider range of selective conditions can be used in vitro than is possible with standard in vivo methods, and many more variants can be handled in vitro than in vivo. This method can be used to isolate the wild-type ribozyme, and structural variants that are as active as the wild type, from a pool of over 250,000 variants in only three cycles of selection and amplification.

Animals↗

Multivariate genetic analysis of Wechsler Intelligence Scale for Children--Revised (WISC-R) factors.

Wechsler Intelligence Scale for Children--Revised (WISC-R) factor scores (Verbal Comprehension, Perceptual Organization, and Freedom from Distractibility) were obtained from 574 twin pairs in the Colorado Reading Project and subjected to multivariate genetic analysis. Variances were partitioned into components common to the three WISC-R factors and to those specific to each factor. Substantial commonality, both genetic and environmental, was found among the three factors. The full model fit the data well, and estimates of heritability and environmentality indicated that about half of the phenotypic variance for each factor is due to additive genetic effects. These results were compared to those obtained in a previous twin study of the three Wechsler Adult Intelligence Scale (WAIS) factors by Tambs et al. (1986).

Adolescent↗

Green fluorescent protein-based reporter systems for genetic analysis of bacteria including monocopy applications.

The green fluorescent protein (GFP) gene, gfp, was used to develop versatile reporter systems for genetic analysis in, and monitoring of bacteria. This reporter system is available on a plasmid and on a mini-transposon located in a suicide delivery plasmid for generation of chromosomal fusions. To achieve sensitivity levels necessary for use in monocopy applications and for detection of single cells, the 3'-end of gfp was replaced by that of a modified gfp gene characterized by a 45-fold stronger fluorescence signal than that exhibited by the natural GFP. This modified gfp gene was also equipped with the strong translation signals of the atpE gene. Transfer of the mini-transposon into two different Pseudomonas spp. and Alcaligenes eutrophus produced random chromosomal fusions, some 5% of which exhibited fluorescence detectable by eye. Individual GFP+ cells were readily observed by fluorescence microscopy.

Bacteria↗

Signal transduction during axon guidance: a genetic analysis in Drosophila.

The searching growth cone simultaneously processes multiple guidance cues and converts them into intracellular signals regulating axon extension, steering and eventually synapse formation. This overlap of signaling pathways ensures functional connectivity of the nervous system during development. While this complicates the genetic analysis of these signaling pathways, combination of genetic techniques available in Drosophila has begun to successfully address the role of some key signaling molecules during axon guidance.

Animals↗

Genetic analysis of absB, a Streptomyces coelicolor locus involved in global antibiotic regulation.

The filamentous soil bacterium Streptomyces coelicolor is known to produce four antibiotics which are genetically and structurally distinct. An extensive search for antibiotic regulatory mutants led to the discovery of absB mutants, which are antibiotic deficient but sporulation proficient. Genetic analysis of the absB mutants has resulted in definition of the absB locus at 5 o'clock on the genetic map. Multiple cloned copies of the actII-ORF4 gene, an activator of synthesis of the antibiotic actinorhodin, restore actinorhodin biosynthetic capability to the absB mutants. These results are interpreted to mean that the failure of absB mutants to produce antibiotics results from decreased expression of the antibiotic genes. The absB gene is proposed to be involved in global regulation of antibiotic synthesis.

Anthraquinones↗

Utility of molecular genetic analysis for the diagnosis of neoplasia in morphologically and immunophenotypically equivocal hematolymphoid lesions.

The authors reviewed retrospectively the results of molecular genetic analysis of 175 hematolymphoid lesions to assess the diagnostic utility of genotyping (analysis for immunoglobulin or beta-chain T-cell receptor gene rearrangements). All cases had been genotyped, and most were also immunophenotyped. Cases were assigned to control (90 cases) or problem groups (85 cases), depending on the absence or presence respectively of diagnostic uncertainty remaining after conventional (morphologic and immunophenotypic) analysis. All control cases had unequivocal morphologic features of non-Hodgkin's lymphoma (NHL) and had appropriate lineage-specific gene rearrangements, but immunostaining was almost as sensitive in demonstrating phenotypes that were diagnostically abnormal as well as lineage-specifying. However, genotyping was clearly diagnostically useful in the problem cases, which included a heterogeneous mixture of nodal and extranodal biopsy specimens of malignant (mostly NHL) and benign lesions. Genotyping demonstrated the appropriate absence or presence of gene rearrangements in 58 of 81 problem cases (72%) ultimately diagnosed as benign or malignant respectively, excluding four cases of Hodgkin's disease; in 25 cases (31%) this was judged to be essential to diagnosis. In the remaining problem cases genotyping did not contribute positively to diagnosis, but in no case was genotyping misleading when cautiously interpreted with primary reliance on conventional analysis and with knowledge of known causes of potentially misleading results, both positive and negative. It is concluded that although genotyping is highly sensitive and specific for hematolymphoid neoplasia, it provides little or no benefit in cases that are unequivocally malignant by conventional analysis, in cases of suspected Hodgkin's disease (HD), or for the sole purpose of lineage assignment. However, in cases whose diagnosis is uncertain after conventional analysis, the high yield of useful information from genotyping with careful interpretation warrants its application.

Gene Rearrangement, B-Lymphocyte↗

Isolation and genetic analysis of Caulobacter mutants defective in cell shape and membrane lipid synthesis.

In this paper we report the isolation, characterization and genetic analysis of several C. crescentus mutants altered in membrane lipid synthesis. One of these, a fatty acid bradytroph, AE6002, was shown to be due to a mutation in the fatA gene. In addition to the presence of the fatA506 mutation, this strain was found to contain two other mutations, one of which caused the production of a water-soluble brown-orange pigment (pigA) and another which caused formation of helical cells (hclA). Expression of the latter two phenotypes required complex media and both were repressed by glucose. However, the lesions were mapped to loci that are separated by a substantial distance. The hclA and the fatA genes mapped close together, possibly implying that comutation had occurred in AE6002. Data are presented that allow the unambiguous identification of a second Fat gene (fatB) in C. crescentus. The map position of another mutation in membrane lipid biogenesis, the glycerol-3-PO4 auxotroph gpsA505, was also determined. During this study the flaZ gene was fine-mapped and the positions of proC and rif changed from the previously reported location.

Chromosome Mapping↗

Genetic analysis of poliovirus protein 3A: characterization of a non-cytopathic mutant virus defective in killing Vero cells.

A mutational and genetic analysis of the poliovirus protein 3A has led to the identification of a single amino acid mutant virus with a restrictive phenotype to form plaques in Vero cells. This mutant (I46T 3A) can be grown and amplified in HeLa cells, where virus replication takes place at wild-type levels. However, Vero cells infected with this virus cannot complete the growth cycle. I46T 3A virus has a defect in the ability to kill Vero cells, as estimated by FACS analysis of propidium iodide uptake by dead cells. Since these defects are observed under conditions where no abnormalities in the rate of synthesis and processing of the mutant polyprotein occur, the inability to induce the cytopathic effect in infected Vero cells denotes the existence of a defect in the activity of 3A, but not the level of expression of the viral genome. As a consequence of this impaired capability to generate the cytopathic effect, I46T 3A mutant viruses cannot be titrated by plaque assay in Vero cells. Only revertant viruses with the wild-type sequence arise and form lysis plaques in Vero cells. Our results suggest a role for the 3A protein (or a precursor thereof) in the virus-induced cytopathic effect. The mutant virus characterized in this work may be a useful tool to understand how poliovirus kills infected cells and carries out the final step of its life-cycle, the release of virus progeny.

Amino Acid Substitution↗