scholarly journals SEGMENTAL ANEUPLOIDY AS A PROBE FOR STRUCTURAL GENES IN DROSOPHILA: MITOCHONDRIAL MEMBRANE ENZYMES

Genetics ◽  
1973 ◽  
Vol 75 (1) ◽  
pp. 155-167
Author(s):  
Stephen J O'Brien ◽  
Richard C Gethmann
Keyword(s):  
Mitochondrial Membrane ◽  
Gene Dosage ◽  
Succinic Dehydrogenase ◽  
Structural Genes ◽  
Malic Dehydrogenase ◽  
Autosomal Region ◽  
Glycerophosphate Dehydrogenase ◽  
Enzyme Systems ◽  
Segmental Aneuploidy ◽  
Chromosome Bands

ABSTRACT A method for detecting possible structural genes in D. melanogaster based on gene dosage dependency is presented. By making thirty crosses between Y-autosome translocations, and an attached-4 cross, it is possible to produce large duplications (approximately 150 salivary gland chromosome bands in length) for every autosomal region with the exception of 83DE. The usefulness of the technique was demonstrated by dosage dependency of three known gene-enzyme systems: α-glycerophosphate dehydrogenase-1, alcohol dehydrogenase and malate dehydrogenase. A screen for genes affecting two enzymes localized on the inner membrane of the mitochondrion, α-glycerophosphate oxidase (αGPO) and succinic dehydrogenase (SHD), produced a dosage-sensitive region in each case. Region 50C-52E affected αGPO activity and region 28D-29F affected SDH activity. The latter region apparently includes the malic dehydrogenase-1 gene. The methodology and limitations of the technique are discussed.

scholarly journals SEGMENTAL ANEUPLOIDY AND ENZYME ACTIVITY AS A METHOD FOR CYTOGENETIC LOCALIZATION IN DROSOPHILA MELANOGASTER

Genetics ◽  
1974 ◽  
Vol 76 (2) ◽  
pp. 301-309
Author(s):  
Barbara R Stewart ◽  
John R Merriam
Keyword(s):  
Enzyme Activity ◽  
X Chromosome ◽  
Gene Dosage ◽  
Chromosome Region ◽  
Structural Genes ◽  
The Third ◽  
Segmental Aneuploidy ◽  
Cytological Localization ◽  
The Relationship ◽  
Chromosome Bands

ABSTRACT A method of mapping genes which specify enzymes without the necessity of obtaining genetic variants has been explored. Three enzymes whose structural genes have known genetic positions were chosen to see if the relationship between gene dosage and enzyme activity could be used as a tool in cytological localization. Zw, the gene specifying G6PD, is located in the X chromosome region, 18D-18F. The structural gene for 6PGD, Pgd, maps in the X chromosome bands 2C1-2E1. Idh-NADP, the gene which specifies IDH-NADP, is found on the third chromosome, in bands 66B-67C.

scholarly journals A Haplolethal Locus Uncovered by Deletions in the Mouse t Complex

Genetics ◽  
2002 ◽  
Vol 160 (2) ◽  
pp. 675-682
Author(s):  
Victoria L Browning ◽  
Rebecca A Bergstrom ◽  
Sandra Daigle ◽  
John C Schimenti
Keyword(s):  
Gene Dosage ◽  
Es Cells ◽  
Embryonic Stem ◽  
Chromosome 17 ◽  
Mammalian Development ◽  
T Complex ◽  
Segmental Aneuploidy ◽  
Systematic Exploration ◽  
Radiation Induced ◽  
Altered Gene

Abstract Proper levels of gene expression are important for normal mammalian development. Typically, altered gene dosage caused by karyotypic abnormalities results in embryonic lethality or birth defects. Segmental aneuploidy can be compatible with life but often results in contiguous gene syndromes. The ability to manipulate the mouse genome allows the systematic exploration of regions that are affected by alterations in gene dosage. To explore the effects of segmental haploidy in the mouse t complex on chromosome 17, radiation-induced deletion complexes centered at the Sod2 and D17Leh94 loci were generated in embryonic stem (ES) cells. A small interval was identified that, when hemizygous, caused specific embryonic lethal phenotypes (exencephaly and edema) in most fetuses. The penetrance of these phenotypes was background dependent. Additionally, evidence for parent-of-origin effects was observed. This genetic approach should be useful for identifying genes that are imprinted or whose dosage is critical for normal embryonic development.

Succinic and Malic Oxidase in Gastric Hydrochloric Acid Production

1956 ◽  
Vol 187 (3) ◽  
pp. 427-431 ◽  
Author(s):  
Joseph J. Vitale ◽  
Oscar M. Jankelson ◽  
Patricia Connors ◽  
D. Mark Hegsted ◽  
Norman Zamcheck
Keyword(s):  
Gastric Mucosa ◽  
Guinea Pig ◽  
Succinic Dehydrogenase ◽  
Titratable Acidity ◽  
Spectrophotometric Analysis ◽  
Parietal Cells ◽  
Human Gastric Mucosa ◽  
City Hospital ◽  
Malic Dehydrogenase ◽  
Oxidase System

Effect of histamine on the activity of succinic oxidase and malic dehydrogenase was studied in guinea pig and human gastric mucosa. Human tissue was obtained through the surgical services of the Boston City Hospital. Control value for the succinic oxidase system of the proximal half of the guinea pig stomach was approximately 480 ( Qo2 (N) (µl O2/mg nitrogen/hr.)). After histamine, this value rose to 550 in 30 minutes with a simultaneous rise in titratable acidity of the stomach contents. Animals fasted for 72 hours had a Qo2 (N) of approximately 500 and after histamine a Qo2 (N) of 700 was observed. Spectrophotometric analysis of succinic dehydrogenase and cytochrome oxidase activities, two of the major components of the succinic oxidase system, revealed that both components are increased following histamine administration. Malic dehydrogenase, however, was not affected by histamine treatment. Succinic dehydrogenase was demonstrated by histochemical localization and was concentrated below the superficial mucous layer where parietal cells were abundant. Succinic oxidase activity of human gastric mucosa was demonstrable only in those specimens containing abundant parietal cells. This study confirms the view that HCl production by parietal cells is associated with aerobic metabolism and is perhaps under enzymatic control. The study suggests that the succinic oxidase system may be involved in the production or secretion of HCl.

Enzyme variation in the Anopheles gambiae Giles group of species (Diptera: Culicidae)

1978 ◽  
Vol 68 (1) ◽  
pp. 85-97 ◽  
Author(s):  
S. J. Miles
Keyword(s):  
Anopheles Gambiae ◽  
Natural Populations ◽  
Lactic Dehydrogenase ◽  
Starch Gel Electrophoresis ◽  
Malic Dehydrogenase ◽  
Glycerophosphate Dehydrogenase ◽  
Starch Gel ◽  
Anopheles Gambiae Giles ◽  
Species Specific ◽  
Glucose 6 Phosphate Dehydrogenase

AbstractThe genotypes of chromosomally-identified individuals from natural populations of the known species of the group of Anopheles gambiae Giles were scored for the enzyme protein structural loci coding for adenylate kinase (Adk), α-naphthyl acetate esterase (Est-1, Est-2, Est-3), glutamic-oxaloacetic transaminase (Got), α-glycerophosphate dehydrogenase (αGpd), hexokinase (Hk), isocitric dehydrogenase (Idh), lactic dehydrogenase (Ldh), ‘leucine’ aminopeptidase (Lap-2), malic enzyme (Me), octanol dehydrogenase (Odh), phosphoglucomutase (Pgm-1, Pgm-2), 6-phosphogluconic dehydrogenase (6-Pgd), phosphohexose isomerase (Phi) and superoxide dismutase (Sod), following starch gel electrophoresis. In the material examined, Est-1, Est-2, Est-3, Got, ldh, Lap-2, Odh, Pgm-1, Pgm-2 and Sod were segregating for two or more alleles; unique alleles at the Est-1, Got and Sod loci produced species-specific phenotypes in A. melas (Theo.), species C and species D, respectively. The further sampling of A. merus Dön, populations supported the presence of a unique SOD phenotype by which this species can also be identified. Of the other enzyme systems examined, no activity following electrophoresis was detected for aldolase and fructose-1,6-diphosphatase, and the resolution of acid and alkaline phosphatase, glyceraldehyde-3-phosphate dehydrogenase, glucose-6-phosphate dehydrogenase, malic dehydrogenase and xanthine dehydrogenase was too poor under the particular electrophoretic conditions for genetic analyses of the enzyme phenotypes.

scholarly journals The Pregnant Syrian Hamster as a Model to Study Intravascular Trophoblasts and Associated Maternal Blood Vessel Changes

1979 ◽  
Vol 16 (5) ◽  
pp. 556-566 ◽  
Author(s):  
J. D. Burek ◽  
B. Goldberg ◽  
G. Hutchins ◽  
J. D. Strandberg
Keyword(s):  
Endothelial Cells ◽  
Blood Vessels ◽  
Succinic Dehydrogenase ◽  
Maternal Blood ◽  
Arterial System ◽  
Elastic Membrane ◽  
Nonspecific Esterase ◽  
Endothelial Lining ◽  
Glycerophosphate Dehydrogenase ◽  
Poorly Differentiated

In pregnant Syrian hamsters (Mesocricetus auratus) used as an animal model for studying the migration of fetal trophoblasts and the associated changes in maternal blood vessels, intravascular trophoblasts migrated well beyond the blood vessels of the uterus and into the vessels of the mesometrium. They migrated beyond the decidua of the uterus, into the lumina of maternal uterine and mesometrial arteries, but not into veins. The arterial changes, which were often segmental, resembled those seen in the decidua and consisted of a replacement of normal smooth muscle cells by poorly differentiated stromal cells. Ultrastructurally, the trophoblasts were either above or below maternal endothelial cells. They occurred also as single or multiple layers within the lumina of arteries that lacked an endothelial lining. Apparent penetration of the elastic membrane by the fetal trophoblasts brought them into close apposition to maternal cells in the arterial wall. Histochemical studies showed heightened metabolic activity of the intravascular trophoblasts as suggested by strong histochemical reactions to nonspecific esterase, succinic dehydrogenase and the glycerophosphate dehydrogenase reactions. Thus, these metabolically active fetal trophoblasts actively migrate into the maternal arterial system, resulting in loss of endothelial cells and changes in the wall of the maternal arteries similar to those in the decidua at the uteroplacental junction.

scholarly journals HISTOCHEMICAL STUDIES OF MITOCHONDRIAL VARIATION DURING AEROBIC GROWTH OF RESPIRATION-NORMAL BAKER'S YEAST

1965 ◽  
Vol 13 (5) ◽  
pp. 344-349 ◽  
Author(s):  
C. J. AVERS ◽  
F. H. LIN ◽  
C. R. PFEFFER
Keyword(s):  
Cytochrome Oxidase ◽  
Succinic Dehydrogenase ◽  
Growth Cycle ◽  
Autonomous Control ◽  
Mitochondrial Enzyme ◽  
Aerobic Growth ◽  
Acceleration Phase ◽  
Enzyme Systems ◽  
Zero Values ◽  
The Common

Histochemical localizations of cytochrome oxidase, succinic dehydrogenase, DPNH-tetrazolium reductase, and TPNH-tetrazolium reductase activities revealed at least two kinds of mitochondria in the intracellular population. The total chondriome in stationary phase cells contains about 45 mitochondria, all with cytochrome oxidase activity. But, only about 30 mitochondria per cell were active for dehydrogenase or reductases. The differences in mitochondrial enzyme activities persisted throughout the growth cycle, showing different numbers of active mitochondria and different rates of their increase and decrease for all four enzyme systems. Manometric data verified the differences between cytochrome oxidase and succinic dehydrogenase for the earlier phases of the growth cycle. In histochemical counts, zero values for all four enzymes occurred in late acceleration phase, but persisted into log phase only for the tetrazolium reductases. Both cytochrome oxidase- and succinic dehydrogenase-active mitochondria began to increase in numbers at the inception of log phase, but at very different rates. The demonstration of more than one kind of mitochondrion in the common nucleocytoplasmic system of a single cell was considered to be evidence of some measure of autonomous control of the mitochondrial phenotype.

scholarly journals Malonate and Carrot Root Respiration

1952 ◽  
Vol 5 (1) ◽  
pp. 64 ◽  
Author(s):  
Vera F Hanly ◽  
KS Rowan ◽  
JS Turner
Keyword(s):  
Organic Acid ◽  
Root Respiration ◽  
Direct Evidence ◽  
Succinic Dehydrogenase ◽  
Low Ph ◽  
Ionic Exchange ◽  
Carrot Root ◽  
Fermentation Products ◽  
Acid Cycle ◽  
Enzyme Systems

Following a review of earlier work with malonate as an enzyme and respiration inhibitor, direct evidence is provided of the existence in carrot root tissue of cytochrome oxidase and succinic dehydrogenase (S.D.). Malonate is clearly effective as an inhibitor of carrot root respiration only at low pH. Its effects at higher pH are, however, fully described and discussed. It is postulated that in this tissue a significant part of the respiration is mediated by enzyme systems not inhibited by malonate, KCN, or CO; that the remainder, whose activity is varied by wounding and aging, and by ionic exchange and uptake, involves an organic acid cycle of the Krebs type. The effects at low pH and low concentration of malonate (O.005-0.02M) may be explained as due to inhibition of succinic dehydrogenase only; under these conditions self reversal of inhibition, and reversal by addition of succinate, are both possible. At higher concentrations ( O.04-0.05M ) and low pH, malonate is assumed to inhibit not only S.D. but other enzymes concerned in pyruvate oxidation; this explains the lack of self reversal, lack of reversal by added succinate, and the failure to demonstrate accumulation of succinate in poisoned tissue; under these conditions, when inhibition is to the basal level, the RQ. is high, presumably because pyruvate is diverted to form fermentation products.

scholarly journals Mouse Models of Aneuploidy

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Olivia Sheppard ◽  
Frances K. Wiseman ◽  
Aarti Ruparelia ◽  
Victor L. J. Tybulewicz ◽  
Elizabeth M. C. Fisher
Keyword(s):  
Mouse Models ◽  
Copy Number ◽  
Gene Dosage ◽  
Altered States ◽  
Cognitive Effects ◽  
Complex Phenotype ◽  
Animal System ◽  
Segmental Aneuploidy ◽  
Number Of Genes ◽  
Number Variation

Abnormalities of chromosome copy number are called aneuploidies and make up a large health load on the human population. Many aneuploidies are lethal because the resulting abnormal gene dosage is highly deleterious. Nevertheless, some whole chromosome aneuploidies can lead to live births. Alterations in the copy number of sections of chromosomes, which are also known as segmental aneuploidies, are also associated with deleterious effects. Here we examine how aneuploidy of whole chromosomes and segmental aneuploidy of chromosomal regions are modeled in the mouse. These models provide a whole animal system in which we aim to investigate the complex phenotype-genotype interactions that arise from alteration in the copy number of genes. Although our understanding of this subject is still in its infancy, already research in mouse models is highlighting possible therapies that might help alleviate the cognitive effects associated with changes in gene number. Thus, creating and studying mouse models of aneuploidy and copy number variation is important for understanding what it is to be human, in both the normal and genomically altered states.

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