Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “GENETICS”

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 775 records · Page 43Linked to original sources
PubMed1996

Future research directions to study genetic damage in germ cells and estimate genetic risk.

The late Frits Sobels developed a parallelogram model to estimate genetic risk to humans based on experimental data in somatic cells (peripheral blood) of exposed animals and humans and on data from progeny studies of exposed animals (mice). Recently, an extension to the original parallelogram model was proposed to bridge the gap of extrapolation between rodent and human germ cells by studying sperm samples. The comparison in the parallelogram of rodent/human sperm data with data from rodent progeny tests to derive at an estimate of human progeny at risk is more promising. Therefore, data on all possible end points, DNA adducts, mutations, chromosomal aberrations, and aneuploidy, should be obtained in sperm of exposed rodents and humans. The technology from somatic cell studies is available or adaptable to sperm studies. Sperm samples lend themselves to automated analyses because they are a homogeneous cell population. By flow cytometry or image analysis, large cell samples can be studied per individual. Animal experiments could be conducted in the actual range of chronic human exposure to low doses. The acceptability of extrapolation from the high acute doses so far used in animal experiments to low chronic doses of human exposure could be assessed. Proof could be obtained in human germ cells for the assumption that data from animal experiments can be extrapolated to humans. Data from transgenic rodent systems may play an important role in the extension of the parallelogram approach to genetic risk estimation by providing a link between cancer and genetic risk estimates.

Aneuploidy↗
PubMed2006

[Influence of maternal genetic effect on genetic parameter estimates of production traits of cashmere goat].

The derivative-free restricted maximum likelihood (DFREML) method was used to compare the differences of genetic parameter estimates of Inner Mongolian Cashmere Goats under two models, which differ in whether maternal genetic effect is taken into account. The differences between the two models were, tested by likelihood ratio test. The results show that maternal genetic effect highly affects live body weight and cashmere thickness while has no significant effect on raw cashmere weight, staple length, fibre diameter and fibre length.

Analysis of Variance↗
PubMed1991

Substrain comparison of genetically hypertensive rats using DNA fingerprinting, and genetic analysis of blood pressure in the inbred rats.

Using DNA fingerprinting, genetic heterogeneity or homogeneity was studied between substrains of spontaneously hypertensive rats (SHR) and Wistar-Kyoto (WKY) rats maintained in Japan. Using human myoglobin minisatellite 33.15 as a probe, we did not detect any inter- or intra-substrain genetic heterogeneities in HinfI digests of SHR or WKY rat DNA. However, analysis of Sau3AI digests of rat DNA using mouse C-6 gene as a probe revealed intra-substrain heterogeneity of 1-2 DNA bands in one of the WKY rat substrains. In the other substrains of SHR and WKY rats, there existed no intra-substrain heterogeneities, but several inter-substrain heterogeneities were observed in both SHR and WKY rats. In another experiment using the inbred substrains of SHR and WKY rats which have been confirmed as genetically homogeneous, we produced F1 and F2 rats, and biometrically analyzed their systolic blood pressure. The results suggested that there may be 1-4 dominant antihypertensinogenic genes with high heritability of 0.6-0.7.

Animals↗
PubMed1991

Genetic improvement programs in livestock: swine testing and genetic evaluation system (stages).

Genetic evaluations for the U.S. swine industry are conducted by the eight purebred associations of the National Association of Swine Records. Within-herd evaluations of the growth traits (days to 105 kg [market] and backfat depth) were first reported in 1986. Analyses of the maternal traits (litter size at birth and weaning, and litter 21-d weight) were inaugurated in 1987. Expected progeny differences (EPD) are reported for all traits and for general, paternal, and maternal bioeconomic indexes. A sow productivity index combining only maternal traits is available. All records are adjusted according to National Swine Improvement Federation (NSIF) guidelines for effects such as number of pigs transferred at crossfostering and age at recorded observation prior to the BLUP evaluation. Within-herd analyses of individual contemporary groups are conducted immediately on receipt of performance records at each breed association office. All parents in the herd and the young pigs in the current group are evaluated. A report is returned to the breeder for use in herd selection and the EPD are placed in the pedigree file. The genetic base of each herd is defined as the first n tested pigs or litters, where n is the number of pigs registered annually within the herd. Change in mean EPD between groups is indicative of genetic trend. Periodic across-herd analyses are used to update interim within-herd analyses and a national sire summary is published.

Animals↗
PubMed1992

Genetic and environmental factors affecting serum macrominerals and weights in an Angus-Brahman multibreed herd: I. Additive and nonadditive group genetic effects of serum calcium, phosphorus, and magnesium and weight at weaning.

Amounts of serum calcium, phosphorus, and magnesium at weaning (WCa, WP, and WMg, respectively) and weaning weights (WW) were obtained from 380 Angus (A), Brahman (B), and A x B calves of various expected A and B fractions reared at the Pine Acres Research Station of the University of Florida, Citra from 1989 to 1990. Calves were produced by mating A, .75A, .25B, .5A .5B, .25A .75B, B, and Brangus (.625A .375B) sires to dams of the same expected breed fractions, except for .25A .75B dams. Best linear unbiased estimates (BLUE) of genetic effects, expressed as regression coefficients, were 1) -15.07 +/- 13.65 mg of WCa, -11.21 +/- 12.07 mg of WP, -1.23 +/- 2.99 mg of WMg, and .66 +/- 1.18 kg of WW for the difference between A and B additive direct; 2) 9.79 +/- 6.94 mg of WCa, -5.72 +/- 6.14 mg of WP, 1.64 +/- 1.52 mg of WMg, and .52 +/- .60 kg of WW for the difference between A and B additive maternal; 3) 242.21 +/- 51.56 mg of WCa, 66.67 +/- 45.62 mg of WP, 52.16 +/- 11.27 mg of WMg, and 22.61 +/- 4.44 kg of WW for A x B nonadditive direct; and 4) 373.63 +/- 38.44 mg of WCa, 93.96 +/- 34.02 mg of WP, 69.90 +/- 8.41 mg of WMg, and 36.83 +/- 3.31 kg of WW for A x B nonadditive maternal. Nonadditive (A x B) effects were the main factors affecting total (sum of additive plus nonadditive) genetic effects in this multibreed population. Total genetic effects were used to rank breed group of sire x breed group of dam combinations.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Genetic and environmental factors affecting serum macrominerals and weights in an Angus-Brahman multibreed herd: II. Heritabilities of and genetic, environmental, and phenotypic correlations among serum calcium, phosphorus, and magnesium and weight at weaning.

Heritabilities of and genetic, environmental, and phenotypic correlations among serum amounts of calcium, phosphorus, and magnesium and weight at weaning (WCa, WP, WMg, and WW, respectively) were estimated for an Angus (A)-Brahman(B) multibreed herd located at the Pine Acres Research Station of the University of Florida, Citra. Records were obtained from 380 calves produced by mating A, .75A .25B, .5A .5B, .25A .75B, B, and Brangus sires across dams of the same breed groups, except for .25A .75B, during 1989 and 1990. Restricted maximum likelihood procedures were used to compute variance and covariance components. Estimates of heritability were .39 (WCa), .40 (WP), .36 (WMg), and .35 (WW). Estimates of genetic, environmental, and phenotypic correlations were .66, .55, .57 (WCa, WP), .70, .71, .70 (WCa, WMg), 1.00, .86, .88 (WCa, WW), .50, .51, .51 (WP, WMg), .78, .60, .63 (WP, WW), and .86, .73, .75 (WMg, WW). These correlations indicate that serum Ca, P, and Mg could be used in multiple-trait genetic evaluation procedures to help identify animals that require low amounts of these macrominerals for preweaning growth. This may prove advantageous in mineral-deficient regions.

Analysis of Variance↗
PubMed2000

[Genetic analysis on flowering and boll setting in upland cotton (Gossypium hirsutum L.). III. Genetic behavior at different developing stages].

An additive-dominant genetic model with genotype by environment interaction was employed to analyze the genetic behavior of flowering and fruiting at different development stages, with 2-year data from 4 x 4 diallel crosses. The results of variance analysis indicated that flowering and fruiting behaviors were mainly controlled by dominant effects at early period, but by additive effects later on. Compared with genetic main effects, GE interaction effects playeda minor role on the flowering and fruiting behavior. The analysis of covariance between average flower number, boll number at different development stages and total number of bolls showed that there were significant positive dominant correlation and negative or zero additive correlation before August 1st, but having the opposite results afterward. Interaction correlation existed during the whole period. It was found, by further analysis of conditional variances, that different development stages have diverse gene action intensity. The last ten days of July and the first-middle ten days of August had the highest gene action level. Time interval of investigation played a great role on exploring the law of gene action during the flowering and fruiting period; when selecting the time interval of investigation, it is necessary to contemplate the purpose of the experiment, environmental condition, investigating traits and developing period simultaneously.

Gossypium↗
PubMed2003

[Studies of genetic structure of genetic relationship of Boer goat and its upgrading offspring to Tangshan Diary goat].

The gentic structure and relationship of Boer goat and its upgrading offspring to Tangshan Dairy goat were studied using the RAPD maker and some statistical program, such as POPGENE, PHYLIP and SPSS. The results indicated that there were the similar percentage of polymorphic loci, observed and effective number of alleles, gene diversity between Boer goat and its upgrading offspring, especially higher upgrading offspring. With the increasing of upgrading, the difference of population structure decreased as well as the genetic distance and differentiation among higher upgrading offspring and their improving parental, but gene flow and genetic identity increased. There was a close genetic relationship between higher upgrading offspring and Boer goat.

English Abstract↗
PubMed1990

Mouse genetics meets molecular biology at Cold Spring Harbor. Mouse Molecular Genetics sponsored by the Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA, August 29-September 2, 1990.

As stated earlier, the digestion of roughly 100 short talks delivered within a few days and containing very condensed information is, even for experts, quite demanding. Sometimes one felt in danger of becoming "psyched out" by all the experiments described; perhaps smaller group discussions dealing with experiments that have not worked, as well as the elimination of redundancies in the presentations, would have added to the flavor of the meeting. But what is the "take home message" from the 1990 CSH Mouse Meeting? With all the described breakthroughs, has mouse molecular genetics and development arrived at a turning point? I am inclined to answer this question with a "yes" on the basis of the following considerations: The elegant studies of development in Drosophila and Caenorhabditis elegans were made possible by the power of genetics with the use of developmental mutations. These studies taught us that the sequential activation of a hierarchy of regulatory genes dictates the temporal and spatial patterns of expression of proteins that define cell phenotypes and the body plan, and thereby control development. With the identification of important regulatory genes responsible for many classical as well as experimentally induced mouse mutations, in conjunction with traditional transgenic studies and the power of deleting and altering genes via ES cell chimeras, the study of mouse development has now gained an important new dimension. It is feasible that the consequences of subtle but precise genetic changes, such as the modification of regulatory elements or DNA-binding domains, can be studied in the whole organism by use of ES cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Genetic and molecular genetic studies of murine and human lupus.

Mice and humans with systemic lupus erythematosus (SLE) have been studied with regard to cellular, genetic and molecular genetic abnormalities. B cell hyperactivity and autoantibody production are the hallmarks of this illness. In humans with SLE, there is increased stem cell, B cell precursor and B cell proliferation. The same is true of NZB mice. In lpr/lpr and gld/gld mice, marked expansion of a subpopulation of T cells allows extrathymic terminal T cell maturation and secondary B cell hyperactivity. Androgens suppress these processes and polyclonal immune activators accelerate them. Three types of genes are identified: inducing genes, accelerating genes and background genes. These give rise to abnormal expression of various cellular oncogenes, T cell receptor genes and immunoglobulin genes. The data suggest that abnormal immune regulation plays a critical role in the development of SLE, with polyclonal B cell activation being common to both mice and humans with SLE. Different genetic and cellular abnormalities underlie the ultimate syndrome, the common denominator, generalized autoimmunity, that we call SLE.

Animals↗
PubMed1982

Genetic regulation of delayed-type hypersensitivity responses to poly (Tyr,Glu)-poly(DLAla)--poly(Lys): expression of the genetic defect in the induction and manifestation phases in H-2s and H-2f mice.

The genetic defect of H-2s and H-2s non-responder mouse strains in both the induction and manifestation phases of delayed-type hypersensitivity (DTH) responses to poly(LTyr,LGlu)-poly(DLAla)--poly(LLys)[(T,G)-A--L] was analysed. Utilizing an in vitro system to activate DTH effector T cells, we observed that non-adherent T cells of (H-2f X H-2b) F1 or (H-2s X H-2b)F1 responder mice, could not be activated on antigen bearing adherent cells of H-2f or H-2s haplotypes. On the other hand, these T cells were effectively sensitized on adherent cells derived from either F1 or parental (H-2b) responder mice. These results indicate that in these mouse strains the genetic defect, in the induction phase of DTH, is expressed at the level of the antigen presenting cell. In subsequent experiments, we were able to "correct' the non-responsiveness of H-2s recipients by transfer of educated and irradiated (H-2s X H-2b)F1 T cells together with normal F1 adherent cells. Normal non-adherent and nylon wool enriched T cells failed to restore these responses. Similarly, antigen-pulsed F1 irradiated peritoneal exudate cells could stimulate DTH responses in SJL recipients of (SJL X C57BL/6)F1 (T,G)-A--L educated cells. The genetic defect of H-2s mice in the manifestation phase of the DTH reaction is thus also expressed on the antigen presenting cell.

Animals↗
PubMed1996

[Cytogenetic abnormalities, genetic alterations, and applications for genetic diagnosis in breast cancer].

The etiology of breast cancer involves a complex interplay of exogenous and endogenous factors, including genetic factors. The identification of oncogenes, tumor suppressor genes and human mismatch repair genes has helped to refine the characterization of breast carcinogenesis. The major types of genetic alterations in breast cancer are amplification of protooncogenes (ERBB2 and MYC) and DNA from chromosome band 11q13; mutation of p53; and loss of heterozygosity on 1p, 3p, 8p, 11p, 13q, 16q, 17p, 17q, 18q. The latter may imply inactivations of tumor suppressor genes. Recently, two distinct familial breast cancer susceptibility genes, BRCA1 and BRCA2, have been isolated. These findings enable to use these genes for genetic diagnosis in clinical oncology.

Breast Neoplasms↗
PubMed2003

Genetics of recurrent early-onset depression (GenRED): design and preliminary clinical characteristics of a repository sample for genetic linkage studies.

This is an initial report on a six-site collaborative project, Genetics of Recurrent Early-Onset Depression (GenRED). This is a study of a large sample of families with recurrent major depressive disorder (DSM-IV) beginning by the age 30 in probands or 40 in relatives. Evidence suggests that early onset and recurrence of depressive episodes predict substantially increased risk of depression in first-degree relatives compared with the general population, suggesting that susceptibility genes might be mapped with this phenotype. The projected sample of 800-1,000 affected sibling pairs (ASPs) and other relatives will be studied using genome scan methods. Biological materials and blinded clinical data will be made available through the NIMH cell repository program. The sample should have good-to-excellent power to detect a locus associated with a 24% or greater population-wide increase in risk to siblings. We describe 838 affected individuals from the first 305 families containing 434 independent ASPs, or 613 ASPs counting all possible pairs. The mean age at the onset was 18.5 years, with a mean of 7.3 episodes and longest episode of 655 days. Almost all subjects had experienced at least 4 weeks of depression with five or more additional symptom criteria. Frequencies of symptoms and psychiatric and medical comorbid are provided. Substance use was more common in males, and panic disorder in females. Within pairs of affected siblings, correlations were significant for age at onset, substance abuse/dependence, panic disorder, obsessive-compulsive disorder and nicotine initiation and persistence. We replicated previously reported associations among comorbid panic disorder and social phobia, chronicity of depression and suicidal behavior. This suggests comparability of our cases to those in earlier large family studies. This dataset should prove useful for genetic studies of a highly familial form of major depressive disorder.

Adult↗
PubMed2003

Genetic analysis of phenotypes derived from longitudinal data: Presentation Group 1 of Genetic Analysis Workshop 13.

The participants of Presentation Group 1 used the GAW13 data to derive new phenotypes, which were then analyzed for linkage and, in one case, for association to the genetic markers. Since the trait measurements ranged over longer time periods, the participants looked at the time dependence of particular traits in addition to the trait itself. The phenotypes analyzed with the Framingham data can be roughly divided into 1) body weight-related traits, which also include a type 2 diabetes progression trait, and 2) traits related to systolic blood pressure. Both trait classes are associated with metabolic syndrome. For traits related to body weight, linkage was consistently identified by at least two participating groups to genetic regions on chromosomes 4, 8, 11, and 18. For systolic blood pressure, or its derivatives, at least two groups obtained linkage for regions on chromosomes 4, 6, 8, 11, 14, 16, and 19. Five of the 13 participating groups focused on the simulated data. Due to the rather sparse grid of microsatellite markers, an association analysis for several traits was not successful. Linkage analysis of hypertension and body mass index using LODs and heterogeneity LODs (HLODs) had low power. For the glucose phenotype, a combination of random coefficient regression models and variance component linkage analysis turned out to be strikingly powerful in the identification of a trait locus simulated on chromosome 5. Haseman-Elston regression methods, applied to the same phenotype, had low power, but the above-mentioned chromosome 5 locus was not included in this analysis.

Cardiovascular Diseases↗
PubMed2005

Analysis of case-control studies of genetic and environmental factors with missing genetic information and haplotype-phase ambiguity.

Case-control studies of unrelated subjects are now widely used to study the role of genetic susceptibility and gene-environment interactions in the etiology of complex diseases. Exploiting an assumption of gene-environment independence, and treating the distribution of environmental exposures as completely nonparametric, Chatterjee and Carroll recently developed an efficient retrospective maximum-likelihood method for analysis of case-control studies. In this article, we develop an extension of the retrospective maximum-likelihood approach to studies where genetic information may be missing on some study subjects. In particular, special emphasis is given to haplotype-based studies where missing data arise due to linkage-phase ambiguity of genotype data. We use a profile likelihood technique and an appropriate expectation-maximization (EM) algorithm to derive a relatively simple procedure for parameter estimation, with or without a rare disease assumption, and possibly incorporating information on the marginal probability of the disease for the underlying population. We also describe two alternative robust approaches that are less sensitive to the underlying gene-environment independence and Hardy-Weinberg-equilibrium assumptions. The performance of the proposed methods is studied using simulation studies in the context of haplotype-based studies of gene-environment interactions. An application of the proposed method is illustrated using a case-control study of ovarian cancer designed to investigate the interaction between BRCA1/2 mutations and reproductive risk factors in the etiology of ovarian cancer.

Algorithms↗
PubMed2001

Preimplantation genetic diagnosis (PGD), a collaborative activity of clinical genetic departments and IVF centres.

Preimplantation genetic diagnosis (PGD) requires the combined efforts of geneticists and workers in the field of reproductive medicine. This was studied on the basis of a questionnaire, sent to 35 members of the PGD Consortium of the European Society of Human Reproduction and Embryology (ESHRE). A reply was obtained from 20 centres. They represent the majority of activities in the field of PGD in the world. It is obvious that many of the activities (in vitro fertilisation, embryo culture and biopsy) take place in IVF units while others (counselling and diagnosis) are the responsibility of genetic diagnostic centres. The distances between both units vary considerably. In all but one centre sex determination is offered. Aneuploidy screening is offered in 13 out of 20 centres. PGD of translocations and other structural chromosome abnormalities is offered in all but one centre. The number of monogenic diseases offered varies considerably. In comparison to prenatal diagnosis PGD is more expensive. The majority of these costs are due to the IVF or ICSI procedure. The charges for PGD vary between about 600 euro and 4000 euro. In 16 out of 20 centres the parents to be must sign an informed consent form.

Aneuploidy↗
PubMed1981

The genetic structure of the Kuwaiti population. I. Distribution of 17 markers with genetic distance analysis.

Frequency estimates were determined on seventeen blood group, serum protein, and red-cell enzyme markers on random samples of 193 individuals from two Bedouin tribes in addition to the general population in Kuwait. Genetic heterogeneity between the three communities is evident from the significant differences in allelic distribution of the polymorphic markers. Genetic distance measurements were used to compare the results with the oral history of descent of the two tribal communities. Results were in agreement with tribal history.

Blood Group Antigens↗
PubMed1989

Genetic polymorphism of human peptidase C, PEPC (E.C.3.4.1.1): formal genetic and population data.

Human peptidase C, PEPC (E.C.3.4.1.1), exhibits a previously undescribed genetic polymorphism, detectable in red cells or leukocytes by starch gel electrophoresis. Segregation analyses on 161 families with 469 offspring support the formal genetic hypothesis of two codominant alleles at an autosomal locus. Since four rare variants have previously been described, we named the polymorphic allele PEPC*6. Gene frequencies from southwestern Germany were PEPC*1 = 0.721 +/- 0.018; PEPC*6 = 0.276 +/- 0.018, and PEPC*R = 0.003 +/- 0.002.

Alleles↗