Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Genetic Structures”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,207 records · Page 67Linked to original sources
PubMed1994

[Isolation and characterization of new nuclear srm gene mutation causing coordinated changes in the maintenance of nuclear and mitochondrial genetic structures in the yeast Saccharomyces].

From grown cultures of UV-irradiated Saccharomyces cerevisiae cells with disomy at chromosome IV, clones with nuclear gene mutations were isolated, each of which was suggested to change both mitochondrial spontaneous rho- mutability and the mitotic stability of extra natural chromosomes. Four such nonallelic mutations (srm8, srm12, srm15, and srm17) were isolated, and their phenotypic expression characterized. All four mutations are associated with decreased spontaneous rho- mutability and virtually block sporulation in homozygous mutant diploids. Mutation srm8 is temperature-sensitive and, most probably, involves an essential gene. Double mutants of genotypes srm8 cdc28-srm and srm8 srm12 are nonviable. Mutation srm12 increases the rate of spontaneous loss of extra chromosome XIV by disomics by a factor of about 30. Mutation srm15 induces a small (about twofold) but statistically significant decrease of this rate. Mutations srm8 and srm17 drastically decelerate reproduction of cells with disomy, which prevents quantitative estimations of rates of loss of extra chromosomes.

Cell Nucleus↗
PubMed1983

Genetic fine structure of the tricarboxylate transport (tct) locus of Salmonella typhimurium.

The tct (tricarboxylate transport) locus of Salmonella typhimurium is found at 59 units between nalB and pheA (Somers et al. 1981). This locus was further resolved by fine structure genetic mapping and by analysis of one of the gene products, the tricarboxylate binding protein (C protein). 135 independent fluorocitrate resistant clones were isolated and 12 point mutants were ordered by 3 point reciprocal crosses using an adjacent Tn10 insertion. Eight spontaneous deletions as well as 17 deletions arising from imprecise excisions of internal and flanking Tn10 elements were used to construct a deletion map comprising 21 deletion segments. 115 strains were than assigned to these segments to complete the fine-structure map. Using the expression of the C protein as a guide, an analysis of a variety of mutant strains indicated: that the tct locus is composed of at least four genes and transcription is clockwise; the C protein structural gene (tctC) resides in the centre of the region and codes for two isoelectric forms of the C gene product; tctC is flanked by two regions which are involved in transport but whose gene products are not yet identified.

Biological Transport, Active↗
PubMed2002

Structuring the genetic heterogeneity of the Basque population: a view from classical polymorphisms.

In this study we analyze 18 classical polymorphisms (ABO, Rh, MNSs, Lewis, P, Duffy, Kell, ADA, ESD, PGM1, PGD, AK1, ACP1, GLO1, HP, GC, TF, and PI) in over 2000 autochthonous individuals from 14 natural districts in three provinces of the Basque Country (Alava, Guipuzcoa, and Biscay). Heterogeneity analysis via the chi2 test and a calculation of F(ST) indicate that there is significant genetic heterogeneity between the Basque districts. The R matrix informs us that this heterogeneity is not significantly concentrated in a single district or in the districts of a single province, but is rather distributed among several districts belonging to the three provinces analyzed. We undertake to assess the influence of various historical, geographical, and cultural factors on the genetic structure of the Basque population. Analysis suggests that allele distribution is geographically patterned in the Basque Country. The gradient distributions observed in the case of some alleles (ABO*O, RH*cDE, RH*cde, MNS*MS, and ACP1*C) on the basis of Moran's autocorrelation coefficient I, along with the influence of the two main travel routes through the Basque Country (western route through Bilbao and eastern route through Vitoria), suggest that the gene flow tends toward the coast. As regards other factors considered (administrative division, repopulation processes, linguistic heterogeneity, and north vs. south cultural heterogeneity), we detected only a certain influence exerted by an old tribal differentiation (2000 B.P.), which would diminish with the passage of time.

Alleles↗
PubMed1988

Molecular genetics and structure of the human immunodeficiency virus.

A novel human lymphotropic virus capable of crippling the immune system by infecting and destroying T4 antigen-positive cells is now known to be the etiologic agent of the acquired immune deficiency syndrome (AIDS). The AIDS or human immunodeficiency virus (HIV) belongs to a family of RNA viruses called retroviruses. Several strains of HIV have been molecularly cloned, and DNA sequence comparisons have established that the proviral DNA genome is 9.7 kilobase pairs. The genome possesses characteristic retrovirus features including structural genes, flanked by long terminal repeats, in the order gag, pol, and env and, in addition, four unique nonstructural genes, several of which appear to be essential in regulating virus replication. Electron microscopy has played an important role in elucidating structural, genetic, and molecular properties of HIV and has aided in its classification as a member of the Lentivirnae retrovirus subfamily. Heteroduplex mapping methodologies pertinent to these findings are described. Although the relationships show considerable divergence, the similarities between HIV and lentiviruses are profound and encompass an indistinguishable morphology, genome sequence homology and topography, genomic diversity, and overlapping biology, including a preference for infecting cells of the immune system, a cytopathic effect in vitro, and the ability to produce a persistent, slowly progressing, degenerative disease in vivo. The newest HIV class (HIV-2) has recently been molecularly characterized. HIV-2 also bears all the hallmarks of a lentivirus but is more closely related to simian immunodeficiency viruses than the previously described HIV-1, despite a similar biology. The HIV-lentivirus phylogenetic relationship has broad implications for the AIDS disease process and has given new importance to the study of the natural history and pathogenesis of animal lentiviruses in searching for clues to prevent the spread of AIDS.

Amino Acid Sequence↗