Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Genetic analysis”

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 1,045 records · Page 58Linked to original sources
PubMed1991

Genetic analysis of a lactococcal plasmid replicon.

The sequence and genetic organization was determined of the 2508 bp lactococcal portion of pFX2, which was derived from a cryptic Lactococcus lactis subsp. lactis plasmid and used as the basis for construction of a series of lactococcal vectors. A lactococcal plasmid plus origin and two replication protein-coding regions (repA and repB) were located. RepA has a helix-turn-helix motif, a geometry typical of DNA-binding proteins. RepB shows a high degree of homology to the plasmid replication initiation proteins from other gram-positive bacteria and Mycoplasma. The transcribed inverted repeat sequence between repA and repB could form an attenuator to regulate pFX2 replication. Up-stream of the ori site, and in a region which was non-essential for replication, a 215 bp sequence identical to the staphylococcal plasmid pE194 and carrying the RSA site was identified. The genetic organization of this lactococcal plasmid replicon shares significant similarity with pE194 group plasmids.

Amino Acid Sequence↗
PubMed1992

Endometrial adenocarcinoma: genetic analysis suggesting heritable site-specific uterine cancer.

UNLABELLED: Genetic factors are clearly integral to the etiology of neoplasia. A cancer family syndrome (Lynch syndrome II) consisting of uterine, colon, and ovarian cancer is recognized, but the heritability of isolated endometrial adenocarcinoma has not otherwise been thoroughly investigated. We have performed pedigree studies in index cases with endometrial adenocarcinoma, using spouses as controls. Preliminary results from 64 probands showed four families in which endometrial adenocarcinoma was diagnosed in at least one first-degree relative of the proband (mother, daughter, sister); none showed relatives with colon or ovarian cancer. In none of the 34 control pedigrees did either a mother or sister have endometrial adenocarcinoma. In four other families, multiple first- and second-degree relatives of probands had adenocarcinoma of the uterus, colon, or ovary, presumably representing a cancer family syndrome (Lynch syndrome II). CONCLUSION: Our preliminary data not only show familial and probably heritable tendencies for endometrial adenocarcinoma, but further suggest that there are at least two distinct forms: (1) the previously described Lynch syndrome II (cancer family syndrome), and (2) a heretofore unemphasized entity characterized by a tendency to endometrial adenocarcinoma alone.

Adenocarcinoma↗
PubMed1998

Molecular genetical analysis of Drosophila ether sensitive mutants.

1. For a genetical approach to the molecular mechanisms of general anesthesia, we isolated 14 Drosophila transposon tagging mutants which showed altered sensitivities to diethylether anesthesia. Two mutated genes were identified and analyzed for their structures and functions. 2. One sensitive mutant, para(hd838), has a transposon, P-element, insertion in the 2nd intron of para locus (14C) which encodes an alpha subunit of a sodium channel. 3. Another sensitive mutant, eth(as)311. has a P-element in the 5'-untranslated region of Drosophila calreticulin gene (86BC). Calreticulin is known as a multifunctional calcium-binding protein in the endoplasmic reticulum of non-muscle cells. 4. We obtained their revertants to show that the P-element insertion in each gene induced the hypersensitivity to ether anesthesia. We describe here that the sodium channel and calreticulin might be targets for the ether anesthesia.

Anesthetics, Inhalation↗
PubMed1994

Genetic analysis of Creutzfeldt-Jakob disease and related disorders.

Genetic studies of over 200 cases of Creutzfeldt-Jakob disease (CJD), Gerstmann-Sträussler-Scheinker syndrome (GSS), fatal familial insomnia (FFI) and kuru have brought a reliable body of evidence that the familial forms of CJD and all known cases of GSS and FFI are linked to germline mutations in the coding region of the PRNP gene on chromosome 20, either point substitutions or expansion of the number of 24-nucleotide repeat units. Phenotypic expression of FFI and familial CJD, clinically and pathologically distinct syndromes linked to the 178Asp-->Asn substitution, is dependent on a polymorphism at codon 129. Synthetic peptides homologous to several regions of PrP spontaneously form insoluble amyloid fibrils with unique morphological characteristics and polymerization tendencies. Peptides homologous to mutated regions of PrP exhibit enhanced fibrillogenic properties and, if mixed with the wild-type peptide, produce even more abundant and larger fibrous aggregates. A similar process in vivo may be the primary event leading to amyloid accumulation and disease.

Adult↗
PubMed2000

Genetic analysis of essential hypertension in Japanese populations.

The reverse genetic approach, which examines genetic factors underlying the root of pathogenesis first, is a powerful tool to clarify the genetic cause of essential hypertension. Using the rat cross model, studies of the genetically hypertensive inbred rat model indicated several candidate loci on the rat chromosome responsible for blood pressure, but failed to identify the exact causal gene. Moreover, it was not certain that the rat data really reflect the human case. Thus, we shifted our focus to human genetics and carried out case control studies using the candidate gene approach. We mainly focused on gene components of the renin-angiotensin system as candidates, finding that angiotensinogen gene polymorphisms are genetic predisposing factors for hypertension. However, the results obtained from case-control studies using Japanese subjects were not consistent, suggesting that there was a problem in control sampling. In our recent study, we recruited more than 5,000 residents of an urban community as a general population and examined the association between genetic factors and their health status. Our results indicate that angiotensin-converting enzyme gene polymorphism is a male-specific genetic risk for essential hypertension. In light of our previous investigations, we present a discussion concerning the design of future studies of the genetics of hypertension.

Angiotensinogen↗
PubMed1971

Genetic analysis of pleiotropic negative sporulation mutants in Bacillus subtilis.

Genetic studies were undertaken on 14 pleiotropic negative sporulation mutants. These mutants (spoA) which are blocked early in the sporulation process were found to map near the terminus of the Bacillus subtilis chromosome in a region enriched in genes involved in spore formation. Two- and three-factor crosses by transduction and transformation led to the conclusion that the pleiotropic spoA mutations formed a linked cluster. The genetic distance across the cluster calculated from transformation data was compatible with the mutant sites defining a single gene. Suppressor studies revealed that either a nonsense or missense mutation in the spoA locus generated a pleiotropic negative phenotype. It was concluded that the locus codes for a protein, and the absence of this protein is responsible for the pleiotropic phenotype.

Bacillus subtilis↗
PubMed1993

Genetic analysis of microcin H47 antibiotic system.

The microcin H47 genetic determinants span a DNA region of ca. 10 kb and represent the first description of an enterobacterial antibiotic system located in the chromosome of the producing strain. Transcriptional and translational fusions to lacZ showed a complex transcriptional organization of the microcin H47 system. Complementation tests identified six genes that are necessary for the production of the antibiotic; the products of two of them are involved in the export of microcin to the extracellular medium. The immunity determinant was located in an 0.8-kb DNA fragment. There is a putative "silent region" of ca. 3 kb inside the system that could not be clearly related to any antibiotic function. Protein products were identified and assigned to three production genes and also to a gene from the silent region.

Anti-Bacterial Agents↗
PubMed1978

Gluten-sensitive enteropathy: genetic analysis and organ culture study in 35 families.

The genetic marker histocompatibility antigen HLA-B8 is present in 80% of patients with gluten-sensitive enteropathy (GSE). We studied 35 families with at least one affected member to determine whether an HLA-region gene alone could determine susceptibility to GSE. The incidence of HLA-B8 in the patients was 69% vs 22% for normals (P less than 0.001). The incidence of GSE in HLA-genotype-identical siblings of patients was only 8%, and in HLA-B8-haplotype-identical siblings and parents of patients was only 14% and 5%, respectively. In addition, intestinal biopsies of HLA-identical or partially identical relatives of patients were studied in an in vitro organ culture system capable of detecting gluten sensitivity in subjects ingesting a normal diet. The results confirmed the low incidence of gluten sensitivity in these individuals. The organ culture system could not differentiate mucosa obtained from unaffected parents or siblings of patients with GSE (who presumably carry the HLA-associated genetic information) from mucosa obtained from normals. We conclude that the genetic material inherited with HLA-B8 alone is not sufficient to produce clinical or subclinical disease. Other genetic and environmental factors appear to be important for disease pathogenesis.

Adolescent↗
PubMed1990

Genetic analysis of population structure in marine teleosts around Japan.

Genetic differentiation and genetic variability were estimated from data on electrophoretically detectable isozymic loci in 12 species of marine teleosts belonging to 10 families of six orders, this study permitted conclusions concerning population structures within the species of marine teleosts. As a result the 12 species could be grouped into two classes, one of which showed higher genetic diversity and included the species inhabiting coastal areas; the other showed lower genetic diversity and included the species inhabiting offshore areas and spawning free pelagic eggs. Class I and Class II could be further divided into two groups (I-1 and I-2, and II-1 and II-2) on the basis of the level of average heterozygosity. Based on the above classification and ecological characteristics, the degree of genetic differentiation may be defined mainly by the level of mixing of eggs and by fry migration, and only to a small extent by adult migration between localities. The degree of average heterozygosity should be a measure of effective population size of the breeding units within the species but not of the whole species. Putting together the above facts, six types of population structure have been proposed for marine teleosts as follows: Species in type I-1 have formed some large populations with large breeding units in offshore areas; Type I-2-1, species have formed a large number of breeding populations with relatively large effective sizes of breeding units in the coastal areas or rivers where they were hatched, even though the species may have migrated over a wide pelagic area during their juvenile to adult stages. The species in type I-2-2 would have formed a number of local subpopulations with large to intermediate breeding units in the coastal areas they inhabit. Type I-2-3 species have formed two or more completely isolated local races (or subspecies) with relatively large breeding units, but with a low level of genetic differentiation within each local race. The species in Type II-1 would have formed a single large population consisting of a few breeding units with large effective sizes in offshore areas around Japan. Type II-2 species would have formed one large population consisting of a large number of breeding units with small effective sizes in wide offshore areas around Japan.

Alleles↗
PubMed1980

[Genetic analysis of human behavior: epistemological methods and limits].

The genetics of human behavior, whether dealing with socio-biology, or with the heritability of schizophrenia or of IQ levels, is currently a controversial domain. The author briefly presents the relatively new methods of genetic pedigree examination utilizing likelihood calculation analyses, and compares this method to the more classical evaluations by family, twin, and adopted children studies. Illustrative examples are drawn from work on the genetics of schizophrenia.

Gene Frequency↗
PubMed2006

Comprehensive genetic analysis of the cystic fibrosis transmembrane conductance regulator from dried blood specimens--implications for newborn screening.

PURPOSE: In the United States, approximately 1/3,700 babies is born with cystic fibrosis each year. The >1,300 documented sequence variants pose a challenge for detection of cystic fibrosis through genetic screening. To investigate whether comprehensive characterization of the cystic fibrosis gene is feasible using dried newborn blood specimens, we modified the whole blood Ambry Test: CF and determined its sensitivity by testing DNA from individuals with cystic fibrosis who still had unknown mutations after commercial mutation panel testing. METHODS: DNA from 42 archived newborn dried blood specimens of affected Hispanic, African-American and Caucasian individuals in California was analyzed by temporal temperature gradient electrophoresis screening and targeted sequencing, and by gross deletion analysis. RESULTS: Excluding two specimens that could not be analyzed due to poor DNA quality, we report a 100% sensitivity and clinical detection rate in the remaining 40 patients. Eighty-three mutations representing 40 different variants were detected, including 8 novel mutations. CONCLUSIONS: This study demonstrates the feasibility of temporal temperature gradient electrophoresis-based full sequence analysis and targeted sequencing from DNA in newborn blood specimens. The Ambry Test: CF, as an additional step in cystic fibrosis newborn screening models, can be used to dramatically reduce the number of cystic fibrosis carrier sweat test referrals.

Blood Specimen Collection↗
PubMed2000

Genetic analysis of homologous DNA recombination in vertebrate somatic cells.

The maintenance of genomic stability and the ability to repair induced DNA damage in vertebrate cells require homologues of the yeast RAD52 epistasis group genes. The homologous recombination carried out by the products of these genes is essential and appears to be closely linked to DNA replication. Defects in recombination and associated activities are implicated in human cancer. This review summarises recent biochemical and genetic findings on the roles played by the vertebrate RAD52 group gene products in recombination. We describe the phenotypic analysis of genetically engineered mammalian and chicken mutants of homologous recombination genes.

Animals↗
PubMed1998

[Genetic analysis of Saccharomyces castellii, S. exiguus and S. martiniae yeasts].

Genetic lines of three biological yeast species of the Saccharomyces sensu lato group--S. castellii, S. exiguus, and S. martiniae--were created. Homo- and heterothalmic monosporic fertile strains were marked by different auxotrophic mutations. Conditions for the hybridization of the Saccharomyces sensu lato yeast were established. The mating of spores or haploid cells of auxotrophic complementary mutants was performed on the complete YPD medium. Prototrophic diploid hybrids were selected on a minimal medium. In S. castellii, the hybridization of diploid cells was demonstrated. All three species studied were suitable for tetrad analysis.

DNA, Fungal↗
PubMed1998

A multivariate quantitative-genetic analysis of behavioral development in mice.

The present experiment attempted a behavior-genetic dissection of early behavioral development in laboratory mice. To this end, we used a full, replicated diallel cross to uncover the genetical architecture as well as the multivariate genetic structure underlying early behavioral ontogeny. A number of standard sensorimotor tests were administered on postnatal Days 3, 5, 8, 10, 13, 17, and 22 to a total of 622 pups from 120 litters (4-6 pups per litter) from a four times replicated complete diallel cross between five inbred mouse strains. The first day on which an animal showed adult performance was taken as its score on that test. MANOVA did not show any effects of the pup's sex on the speed of development. Hayman's analysis of variance for diallel tables indicated no or only weak additive-genetic effects. Dominance was absent in almost all cases, except for the auricular startle response, where weak directional dominance for fast development was found. These results are in accordance with an evolutionary past of directional selection for well-canalized development. Factor analyses of the phenotypic and additive-genetic correlation matrices indicate that at least two factors are necessary to describe the behavioral variation.

Adaptation, Psychological↗
PubMed2001

Mississippians in motion? A population genetic analysis of interregional gene flow in West-Central Illinois.

Population genetic and biological distance studies of Late Woodland and Mississippian populations from west-central Illinois have provided insight into a number of prehistoric demographic processes at the regional level. However, a formal analysis of diachronic interregional gene flow has not been attempted within a population genetics framework. In this study, cranial measurements of 489 individuals from 13 skeletal samples across the central and lower Illinois valleys are analyzed to address two central issues. First, the potential impact of Cahokia's decline and associated demographic events on the population structure of west-central Illinois Mississippians is examined. Second, the Mississippian and Late Woodland interregional migration patterns are compared to determine if geographic and/or cultural boundaries affected local population structure. Following Relethford and Blangero ([1990] Hum Biol 62:5-25), R matrix methods are utilized to calculate observed and expected phenotypic variances, minimum genetic distances, and F(ST) values in order to detect patterns of differential external gene flow over time. The results indicate that Late Woodland peoples had a larger sphere of biological interaction than Mississippians. In the Mississippian period, culturally imposed barriers paralleled geographic boundaries between regions such that the geographic distribution of biological variation closely adheres to a classic isolation-by-distance model. Further, intraregional population movement was a more significant contributor to Mississippian population structure than interregional gene flow, even during periods of sociopolitical strife. Small-scale intraregional shuffling is consistent with other recent studies of prehistoric Mississippian biocultural and geographic landscapes in the southeast United States.

Adolescent↗
PubMedDate not supplied

[Validation of a Bruton's disease genetic analysis method].

Bruton's disease is the most frequently primary X-linked immunodeficiency. Patients are more susceptible to early and recurring infections associated with hypo/agammaglobulinemia and a severe B-cell deficiency. Moreover, 400 mutations were found in the XLA gene which codes the Btk tyrosine kinase and were identified as responsible for Bruton's disease. Genetic study was carried out with one group of patients named NECKER, composed by five XLA patients and two parents whose XLA gene was sequenced by an Italian crew. Results were obtained by PCR of 19 exons and initial/terminal intron's parts, followed by PCR-sequencing with universal primers and sequencing. The results from this study allowed the validation of the sequencing technique by comparing NECKER group data (equivalent results with Italian data). In addition, the mutation multiplicity (described or not, coding/non coding) need an exact analysis that should be given to clinicians through clear and trustful results. In this way, a strategy to analyse untreated results was created based on the mutation type. The genetic analysis could help physicians for uncertain diagnosis in immune defficiencies, allows proposing a genetic advice to the patient's family and the construction of a data base permits a best understanding of this disease.

Agammaglobulinaemia Tyrosine Kinase↗
PubMed2025

Genetic analysis of Schistosoma mansoni in a low-transmission area in Brazil suggests population sharing between wild-hosts and humans and geographical isolation.

BACKGROUND: The fluke Schistosoma mansoni is the causative agent of intestinal schistosomiasis, a neglected tropical disease, and remains prevalent in certain regions of Brazil. In the municipality of Sumidouro, state of Rio de Janeiro, Brazil, a low-endemic area for S. mansoni, water rats (Nectomys squamipes) are naturally infected by this trematode. The S. mansoni populations infecting humans and water-rats in Sumidouro exhibit distinct patterns of cercarial emergence (chronotypes) and phenotypic differences between hosts. Previous studies have shown that the adaptation of S. mansoni populations to human hosts (diurnal chronotype) and water rats (nocturnal chronotype) could result in prezygotic isolation. To test this hypothesis, we employed the mitochondrial cytochrome c oxidase subunit 1 gene (MT-CO1) and microsatellite loci as genetic markers. PRINCIPAL FINDINGS: We assessed the population structure between the definitive host species and geographically distant isolates collected from two endemic localities (Pamparrão-PAM and Encanto-Soledade-ENC-SOL) in Sumidouro. Additionally, we evaluated the phylogenetic relationships between S. mansoni from Sumidouro and those from other countries. Five haplotypes of the MT-CO1 gene were identified, with haplotypes 3 and 4 exclusive to ENC-SOL, and haplotypes 1, 2, and 3 were shared between humans and water rats. Haplotype 1 was also shared with other Brazilian localities, South American countries and a single locality in West Africa. The remaining haplotypes were exclusive to Sumidouro, indicating local genetic diversity. Population structure analysis revealed no genetic differentiation associated with host species but rather geographical structuring, probably due to the sedentary habits of rodents and the limited movement of humans between localities. This finding indicates that S. mansoni populations with different chronotypes are not genetically isolated and that significant gene flow occurs between them. CONCLUSIONS: In conclusion, our findings confirm that wild rodents contribute to the maintenance of the S. mansoni life cycle in Sumidouro and can serve as indicators of local transmission hotspots.

Animals↗