One Gene vs. Two Genes in Schizophrenia

1974 ◽  
Vol 125 (587) ◽  
pp. 348-349 ◽  
Author(s):  
Carol Buck
Keyword(s):  
Single Gene ◽  
Genetic Models ◽  
Intermediate Model ◽  
Genetic Mechanisms

Arguments about the role of heredity in schizophrenia have largely given way to arguments about the genetic mechanisms involved. Discussions of the various genetic models by leading workers in the field have been presented in recent years (Rosenthal and Kety, 1968; Kaplan, 1972). Single gene theories have prevailed, Slater's intermediate model being preferred because of its good fit with the observed risks of schizophrenia in specific categories of blood relatives (Slater and Cowie, 1971).

scholarly journals Osteoarthritis: Insights Offered by the Study of Bone Mass Genetics

2021 ◽  
Vol 19 (2) ◽  
pp. 115-122
Author(s):  
A. Hartley ◽  
C. L. Gregson ◽  
L. Paternoster ◽  
J. H. Tobias
Keyword(s):  
Bone Mass ◽  
Causal Effect ◽  
Mendelian Randomisation ◽  
Mineral Density ◽  
High Bone Mass ◽  
Increased Risk ◽  
High Bone ◽  
Genetic Mechanisms ◽  
Additional Support

Abstract Purpose of Review This paper reviews how bone genetics has contributed to our understanding of the pathogenesis of osteoarthritis. As well as identifying specific genetic mechanisms involved in osteoporosis which also contribute to osteoarthritis, we review whether bone mineral density (BMD) plays a causal role in OA development. Recent Findings We examined whether those genetically predisposed to elevated BMD are at increased risk of developing OA, using our high bone mass (HBM) cohort. HBM individuals were found to have a greater prevalence of OA compared with family controls and greater development of radiographic features of OA over 8 years, with predominantly osteophytic OA. Initial Mendelian randomisation analysis provided additional support for a causal effect of increased BMD on increased OA risk. In contrast, more recent investigation estimates this relationship to be bi-directional. However, both these findings could be explained instead by shared biological pathways. Summary Pathways which contribute to BMD appear to play an important role in OA development, likely reflecting shared common mechanisms as opposed to a causal effect of raised BMD on OA. Studies in HBM individuals suggest this reflects an important role of mechanisms involved in bone formation in OA development; however further work is required to establish whether the same applies to more common forms of OA within the general population.

‘Generic’ physical mechanisms of morphogenesis and pattern formation

Development ◽  
1990 ◽  
Vol 110 (1) ◽  
pp. 1-18 ◽  
Author(s):  
S.A. Newman ◽  
W.D. Comper
Keyword(s):  
Pattern Formation ◽  
Reaction Diffusion ◽  
Physical Mechanisms ◽  
Extracellular Matrix Components ◽  
Genetic Mechanisms ◽  
Chemical Waves ◽  
Phylogenetic Lineages ◽  
Living Tissues ◽  
Highly Evolved

The role of ‘generic’ physical mechanisms in morphogenesis and pattern formation of tissues is considered. Generic mechanisms are defined as those physical processes that are broadly applicable to living and non-living systems, such as adhesion, surface tension and gravitational effects, viscosity, phase separation, convection and reaction-diffusion coupling. They are contrasted with ‘genetic’ mechanisms, a term reserved for highly evolved, machine-like, biomolecular processes. Generic mechanisms acting upon living tissues are capable of giving rise to morphogenetic rearrangements of cytoplasmic, tissue and extracellular matrix components, sometimes leading to ‘microfingers’, and to chemical waves or stripes. We suggest that many morphogenetic and patterning effects are the inevitable outcome of recognized physical properties of tissues, and that generic physical mechanisms that act on these properties are complementary to, and interdependent with genetic mechanisms. We also suggest that major morphological reorganizations in phylogenetic lineages may arise by the action of generic physical mechanisms on developing embryos. Subsequent evolution of genetic mechanisms could stabilize and refine developmental outcomes originally guided by generic effects.

scholarly journals Genetic Mechanisms behind the Spread of Reduced Susceptibility to Azithromycin in Shigella Strains Isolated from Men Who Have Sex with Men in Québec, Canada

2018 ◽  
Vol 63 (2) ◽  
pp. e01679-18 ◽  
Author(s):  
Khadidja Yousfi ◽  
Christiane Gaudreau ◽  
Pierre A. Pilon ◽  
Brigitte Lefebvre ◽  
Matthew Walker ◽  
...  
Keyword(s):  
Sequence Analysis ◽  
Shigella Flexneri ◽  
Complete Sequence ◽  
Shigella Sonnei ◽  
Content Type ◽  
Genetic Mechanisms ◽  
Sex With Men

ABSTRACT We analyzed 254 Shigella species isolates collected in Québec, Canada, during 2013 and 2014. Overall, 23.6% of isolates showed reduced susceptibility to azithromycin (RSA) encoded by mphA (11.6%), ermB (1.7%), or both genes (86.7%). Shigella strains with RSA were mostly isolated from men who have sex with men (68.8% or higher) from the Montreal region. A complete sequence analysis of six selected plasmids from Shigella sonnei and different serotypes of Shigella flexneri emphasized the role of IS26 in the dissemination of RSA.

Reaching Future Scientists, Consumers, & Citizens

2014 ◽  
Vol 76 (6) ◽  
pp. 379-383 ◽  
Author(s):  
Melissa A. Hicks ◽  
Rebecca J. Cline ◽  
Angela M. Trepanier
Keyword(s):  
Personalized Medicine ◽  
Genetic Basis ◽  
Genetic Disorders ◽  
Single Gene ◽  
Personal Health ◽  
Adult Onset ◽  
Biology Textbooks ◽  
Multifactorial Diseases ◽  
Single Gene Disorders

An understanding of how genomics information, including information about risk for common, multifactorial disease, can be used to promote personal health (personalized medicine) is becoming increasingly important for the American public. We undertook a quantitative content analysis of commonly used high school textbooks to assess how frequently the genetic basis of common multifactorial diseases was discussed compared with the “classic” chromosomal–single gene disorders historically used to teach the concepts of genetics and heredity. We also analyzed the types of conditions or traits that were discussed. We identified 3957 sentences across 11 textbooks that addressed multifactorial and “classic” genetic disorders. “Classic” gene disorders were discussed relatively more frequently than multifactorial diseases, as was their genetic basis, even after we enriched the sample to include five adult-onset conditions common in the general population. Discussions of the genetic or hereditary components of multifactorial diseases were limited, as were discussions of the environmental components of these conditions. Adult-onset multifactorial diseases are far more common in the population than chromosomal or single-gene disorders; many are potentially preventable or modifiable. As such, they are targets for personalized medical approaches. The limited discussion in biology textbooks of the genetic basis of multifactorial conditions and the role of environment in modifying genetic risk may limit the public’s understanding and use of personalized medicine.

Optimal sampling for pedigree analysis: tracing a single gene

1982 ◽  
Vol 14 (4) ◽  
pp. 752-762 ◽  
Author(s):  
E. A. Thompson
Keyword(s):  
Probability Distribution ◽  
Single Gene ◽  
Pedigree Analysis ◽  
Genetic Models ◽  
Optimal Sampling ◽  
Large Pedigree ◽  
Sequential Procedures ◽  
Rare Gene ◽  
Enhance Efficiency ◽  
Sampling Rule

In fitting genetic models on the basis of observations on an interrelated structure, sequential procedures can enhance efficiency. In this paper we consider the case of a rare gene segregating in a single large pedigree. The sampling rule is dictated by the effect of observations on the genotypic probability distribution of unobserved relatives; this effect is investigated.

scholarly journals Study of Staphylococcus aureusPathogenic Genes by Transfer and Expression in the Less Virulent Organism Streptococcus gordonii

2001 ◽  
Vol 69 (2) ◽  
pp. 657-664 ◽  
Author(s):  
P. Stutzmann Meier ◽  
J. M. Entenza ◽  
P. Vaudaux ◽  
P. Francioli ◽  
M. P. Glauser ◽  
...  
Keyword(s):  
Single Gene ◽  
Individual Factors ◽  
Gene Products ◽  
Streptococcus Gordonii ◽  
Pathogenic Role ◽  
Gain Of Function ◽  
Function Strategy

ABSTRACT Because Staphylococcus aureus strains contain multiple virulence factors, studying their pathogenic role by single-gene inactivation generated equivocal results. To circumvent this problem, we have expressed specific S. aureus genes in the less virulent organism Streptococcus gordonii and tested the recombinants for a gain of function both in vitro and in vivo. Clumping factor A (ClfA) and coagulase were investigated. Both gene products were expressed functionally and with similar kinetics during growth by streptococci and staphylococci. ClfA-positive S. gordoniiwas more adherent to platelet-fibrin clots mimicking cardiac vegetations in vitro and more infective in rats with experimental endocarditis (P < 0.05). Moreover, deletingclfA from clfA-positive streptococcal transformants restored both the low in vitro adherence and the low in vivo infectivity of the parent. Coagulase-positive transformants, on the other hand, were neither more adherent nor more infective than the parent. Furthermore, coagulase did not increase the pathogenicity ofclfA-positive streptococci when both clfA andcoa genes were simultaneously expressed in an artificial minioperon in streptococci. These results definitively attribute a role for ClfA, but not coagulase, in S. aureus endovascular infections. This gain-of-function strategy might help solve the role of individual factors in the complex the S. aureus-host relationship.

Genes necessary for C. elegans cell and growth cone migrations

Development ◽  
1997 ◽  
Vol 124 (9) ◽  
pp. 1831-1843 ◽  
Author(s):  
W.C. Forrester ◽  
G. Garriga
Keyword(s):  
Cell Fate ◽  
Single Gene ◽  
Growth Cones ◽  
Cell Fate Specification ◽  
Fate Specification ◽  
C Elegans ◽  
Final Destination ◽  
Multiple Cell

The migrations of cells and growth cones contribute to form and pattern during metazoan development. To study the mechanisms that regulate cell motility, we have screened for C. elegans mutants defective in the posteriorly directed migrations of the canal-associated neurons (CANs). Here we describe 14 genes necessary for CAN cell migration. Our characterization of the mutants has led to three conclusions. First, the mutations define three gene classes: genes necessary for cell fate specification, genes necessary for multiple cell migrations and a single gene necessary for final positioning of migrating cells. Second, cell interactions between the CAN and HSN, a neuron that migrates anteriorly to a position adjacent to the CAN, control the final destination of the HSN cell body. Third, C. elegans larval development requires the CANs. In the absence of CAN function, larvae arrest development, with excess fluid accumulating in their pseudocoeloms. This phenotype may reflect a role of the CANs in osmoregulation.

Genetics of Anxiety Disorders

2013 ◽  
pp. 537-546
Author(s):  
Javier A. Perez ◽  
Takeshi Otowa ◽  
Roxann Roberson-Nay ◽  
John M. Hettema
Keyword(s):  
Anxiety Disorders ◽  
Personality Traits ◽  
Molecular Genetics ◽  
Genetic Epidemiology ◽  
Genetic Models ◽  
Pediatric Anxiety ◽  
Clinical Syndromes ◽  
Genetic Mechanisms ◽  
The Individual ◽  
Insight Into

This chapter provides a broad overview of the state of current research in the genetics of the major anxiety disorders. In addition tosummarizing findings regarding the individual clinical syndromes, we present data supporting genetic hypotheses that explain their comorbidity with each other and with related phenotypessuch as anxious personality traits and depression. We conceptually divide the chapter into three main sections based upon methodology: (1) genetic epidemiology of adult and pediatric anxiety (twin and family studies), (2) human molecular genetics (linkage and association), and (3) animal genetic models. These approaches provide complimentary and concurring evidence supporting the genetic basis underlying anxiety disorders as well as preliminary insight into the genetic mechanisms involved in their expression.

scholarly journals Loss of PTEN in Fallopian Tube Epithelium Results in Multicellular Tumor Spheroid Formation and Metastasis to the Ovary

Cancers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 884 ◽  
Author(s):  
Matthew Dean ◽  
Vivian Jin ◽  
Tova M. Bergsten ◽  
Julia R. Austin ◽  
Daniel D. Lantvit ◽  
...  
Keyword(s):  
Fallopian Tube ◽  
Single Gene ◽  
Similar Rate ◽  
Genetic Alterations ◽  
Wild Type ◽  
Spheroid Formation ◽  
Multicellular Tumor Spheroid ◽  
Ovarian Stroma

High-grade serous ovarian cancer (HGSOC) can originate in the fallopian tube and then spread to the ovary. Our objective was to evaluate the role of multicellular tumor spheroids (MTS) in ovarian metastasis. By testing a panel of murine oviductal epithelial (MOE) cells with genetic alterations mimicking those seen in HGSOC, we found that loss of PTEN allowed MTS formation under ultra-low adhesion conditions. Confirming these results in vivo, MTS-like structures were observed in the oviducts of PAX8Cre/+ PTENflox/flox mice. MOE PTENshRNA cells could incorporate up to 25% wild type cells into MTS, while higher percentages of wild type cells resulted in a loss of MTS formation. MTS formation allowed MOE PTENshRNA cells to survive better under ultra-low adhesion conditions than control cells. MTS also attached to the ovarian stroma, as would be exposed during ovulation. Interestingly, MTS more robustly cleared monolayers of murine ovarian surface epithelia than murine ovarian fibroblasts. When xenografted into the ovarian bursa, OVCAR8 MTS were able to form tumors in the ovary at a similar rate as an equal number of OVCAR8 cells grown on traditional cell culture plastic. In conclusion, loss of a single gene (PTEN) allows the fallopian tube epithelia to form MTS, which survive better under ultra-low adhesion conditions, attach to the extracellular matrix exposed during ovulation, and colonize the ovary. These results suggest that MTS may contribute to seeding of the ovary in HGSOC patients.

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