ABSTRACT
BACKGROUND: Failure of Alzheimer's disease and related diseases (ADRD) research studies to include and engage Black participants is a major issue, which limits the impact and generalizability of research findings. Little is known about participation of Black adults in online ADRD-related research registries. OBJECTIVES: As part of the Community Engaged Digital Alzheimer's Research (CEDAR) Study, this study aims to increase our understanding of facilitators and barriers of Black adults to participating in ADRD-related online registries, as well as to understand their preferences for communication channels. DESIGN, SETTING, PARTICIPANTS, MEASUREMENTS: We invited all Black participants enrolled in the Brain Health Registry (BHR) to complete a cross-sectional online survey. The survey consisted of rating scales and open-text questions asking about their attitudes towards brain health research, reasons for joining and continuing to participate in BHR, difficulties with participating, and preferences for modes of contact and website usage. RESULTS: Of all invited Black BHR participants (N=3,636), 198 (5.5%) completed the survey. The mean age was 58.4 (SD=11.3), mean years of education were 16.3 (SD=2.4), and 85.5% identified as female. Reported facilitators for joining and continuing to participate in BHR were personal interest (e.g., learning more about own brain health) and altruism (e.g., helping research). Among additional registry features which could encourage return, receiving feedback or scores about BHR tasks was rated the highest. Of those who found BHR participation difficult (21%), the most frequent reason was time burden. The most preferred way of receiving study information was via email. Participants reported that the websites that they used the most were YouTube and Facebook. DISCUSSION: The results of our study can inform the development of culturally-responsive registry features and engagement efforts to improve inclusion and participation of Black adults in online ADRD research. Providing participants with feedback about their registry performance and reducing the number of registry tasks are among the recommended strategies.
Subject(s)
Alzheimer Disease , Registries , Female , Humans , Middle Aged , Black People , Brain , Cross-Sectional Studies , Aged , Black or African AmericanABSTRACT
OBJECTIVE: The tissue contraction phenomenon associated with wound healing is of prime importance for wound closure. Contractile properties of human fibroblasts from chronic venous leg ulcers were compared with those of normal fibroblasts using in vitro models. METHOD: Biopsies were taken from the uninvolved skin of the thigh, the epithelialised ulcer edge and the non-epithelialised ulcer centre in four patients (average age: 78 years). Fibroblasts were obtained by an explant technique and expanded in vitro in Dulbecco's Modified Eagle's Medium supplemented with 10% foetal calf serum and used for the assays at their fourth passage. Intracellular alpha-smooth muscle actin expression (alphaSM-actin) was studied by immunofluorescence labelling of cells cultured in monolayer. Contractile properties were evaluated using three-dimensional collagen lattices. RESULTS: Fibroblasts from the ulcer centre were the richest cells in actin filaments. Both populations of venous ulcer fibroblasts contracted more rapidly and to a greater extent than normal fibroblasts. The peak contractile forces developed by fibroblasts from the ulcer centre and the ulcer edge were 30% and 18% greater than normal fibroblasts respectively. CONCLUSION: Some functions of fibroblasts, in particular the generation of contractile forces and the formation of cytoplasmic actin filaments, seem not to be affected in chronic venous ulcers. DECLARATION OF INTEREST: This study was supported by the Fondation Coloplast pour la Qualite de la Vie of France.
Subject(s)
Fibroblasts/physiology , Varicose Ulcer/pathology , Wound Healing/physiology , Actin Cytoskeleton/physiology , Actin Cytoskeleton/ultrastructure , Aged , Biopsy , Case-Control Studies , Cells, Cultured , Chronic Disease , Elasticity , Female , Fibroblasts/ultrastructure , Fluorescent Antibody Technique , Humans , Varicose Ulcer/etiology , Varicose Ulcer/physiopathologyABSTRACT
OBJECTIVE: We compared the effects on cultured human fibroblasts of a new non-adhesive wound dressing, Urgotul, with five other wound dressings. Urgotul is a hydrocolloid dressing; the comparator dressings included impregnated gauze and modern wound dressings. METHOD: Cultures in monolayer were used to study the morphology and growth of fibroblasts. The Bell model of cultured dermis equivalents was used to investigate myofibroblast differentiation. These cultures were labelled a-SM actin and F-actin. RESULTS: Two of the tested dressings induced cytotoxic effects. They were found to inhibit cell growth (greater than 60%) and to disturb cell shape and cytoskeletal differentiation. Urgotul and the remaining three dressings showed no effect on proliferation. However, some of them modified fibroblast morphology and affected F-actin distribution. CONCLUSION: Depending on their nature and components, wound dressings may respect or affect fibroblast behaviour in vitro (proliferation, morphology and a-SM actin and F-actin distribution). The significance of these in vitro observed findings require further investigations.
Subject(s)
Collagen/drug effects , Colloids/pharmacology , Fibroblasts/drug effects , Wound Healing/drug effects , Actins/metabolism , Bandages , Bandages, Hydrocolloid , Cells, Cultured , Collagen/metabolism , Fibroblasts/metabolism , Humans , In Vitro Techniques , Wounds and Injuries/metabolism , Wounds and Injuries/nursingABSTRACT
BACKGROUND/AIMS: Collagen lattices are an in vitro dermal equivalent that has led to the development of an original model of dermal tissue. Fibroblasts cultured in three-dimensions in a collagen matrix differentiate similarly to in vivo. New technological performances in ultrasonic imaging can now provide precise measurements of tissue thickness with good resolution. The aim of this study was to assess, by B-scan echography, the correlation between collagen lattice thickness and various collagen and cell concentrations. METHODS: Three concentrations of human dermal fibroblasts (F1 = 8.10(5)C/mL, F2 = 16.10(5)C/mL, F3 = 32.10(5)C/mL) and three concentrations of rat tail collagen (C1 = 2 mg mL(-1), C2 = 3 mg mL(-1), C3 = 4 mg mL(-1)) were prepared for five different kinds of collagen lattices: F(2)C(1), F(2)C(2), F(2)C(3), F(1)C(1) and F(3)C(1) (n = 5 per case). Ultrasonic imaging was performed on day 0, 4, 6, 10, 12 and 14 using a Dermcup 2020 scanner. The scans measured thickness in the centre and periphery of the lattice. RESULTS: The collagen lattice echogenicity was similar to a dermis in vivo. For each assessment, the collagen lattice thickness increased until day 12 and then stabilized. The lattice was thicker when the cellular concentration was higher, (at day 14: F(1C1) = 0.66 mm, F(2C1) = 0.86 mm, F(3C1) = 1.21 mm). The collagen concentration did not significantly influence lattice thickness. CONCLUSION: Collagen lattice thickness increased with retraction time and cellular concentration.
Subject(s)
Collagen/chemistry , Collagen/metabolism , Skin/diagnostic imaging , Skin/metabolism , Ultrasonography/methods , Animals , Cells, Cultured , Chemical Phenomena , Chemistry, Physical , Dermis/cytology , Dermis/diagnostic imaging , Dermis/physiology , Fibroblasts/diagnostic imaging , Fibroblasts/physiology , Humans , Infant, Newborn , Male , Osmolar Concentration , Rats , Reference Values , Time FactorsABSTRACT
Two major forms of glutathione S-transferase are known in Drosophila melanogaster: GST D and GST 2. In the present paper we report the existence of a third major form of glutathione S-transferase in Drosophila simulans. Induction with phenobarbital revealed a different regulation of GST between these species. Despite the fact that these two species are closely related, there was a difference in the expression profile of the enzyme implicated in the detoxification system, suggesting variations in capacity to suit their environment.
Subject(s)
Drosophila melanogaster/classification , Drosophila melanogaster/enzymology , Drosophila/classification , Drosophila/enzymology , Glutathione Transferase/biosynthesis , Animals , Blotting, Western , Glutathione Transferase/isolation & purification , Phenobarbital/pharmacology , Protein Isoforms , Species SpecificityABSTRACT
Striae distensae are characterized by linear, smooth bands of atrophic-appearing skin. Excessive steroid activity, genetic and mechanical factors and inherited defects of connective tissues are the most frequent causes of this disease. Fibroblasts derived from women presenting striae distensae lesions were included into collagen gels to study their mechanical behavior: capacity to contract free-floating lattices and to produce isometric force in tense lattices. To measure the retracted lattice diameter, the culture dishes were placed on a transparent metric scale. An isometric force system was used to study quantitatively the forces developed during lattice contraction. alpha 2 beta 1 integrins expression (transmembrane receptors) was evaluated by flux cytometry. Striae distensae fibroblasts contract collagen gels slower than normal human fibroblasts but the final contraction is similar. They produce a greater isometric force which is associated with enhanced alpha 2 beta 1 integrins expression. By their mechanical properties, striae distensae fibroblasts appear as a different population from normal fibroblasts.
Subject(s)
Collagen/metabolism , Fibroblasts/physiology , Skin Diseases/physiopathology , Adult , Biomechanical Phenomena , Female , Flow Cytometry , Humans , Integrins/analysis , Isometric Contraction , Receptors, Collagen , Skin Diseases/pathologyABSTRACT
In the present study, we describe the structural and cytological changes observed in staggerer mutant olfactory bulbs, as compared to normal mice. On the basis of photonic and ultrastructural observations we tried to define the alterations induced by the mutation: i.e. a reduction of bulb size, a reduction in the volume of three out of the six architectonic layers (glomerular, external and internal plexiform), a reduction of glomeruli size, a loss of half the mitral cells and a slight decrease in juxtaglomerular interneuron number. In staggerer, an hypertrophy of glial ensheathing cell processes was especially evident at the level of each glomerulus, whereas the density of the astrocyte network was weaker in the granular layer and the nerve layer not apparently impaired. An immunofluorescent labelling study combined with confocal scanning microscopy was performed in order to identify the cellular type and the differentiation degree of the various elements. Antibodies anti-GFAP, a protein present in both ensheathing cells and astrocytes, and anti-OMP, the specific maturation protein of the nerve layer, were used for that purpose. Data confirmed the reality of the gliosis and the persistence of the sensory component in the mutant. All the structural alterations described in staggerer olfactory bulb were in close agreement with the functional troubles previously recorded. Our results are discussed in connection with the present knowledge on embryonal origin, fetal development and adult cellular renewal of the olfactory bulb.
Subject(s)
Cerebellar Diseases/pathology , Mice, Neurologic Mutants/anatomy & histology , Nerve Degeneration/pathology , Olfactory Bulb/pathology , Receptors, Cytoplasmic and Nuclear/deficiency , Trans-Activators/deficiency , Animals , Biomarkers , Cell Count , Cell Differentiation , Cerebellar Diseases/genetics , Gene Deletion , Glial Fibrillary Acidic Protein/analysis , Male , Mice , Mice, Inbred C57BL , Microscopy, Confocal , Microscopy, Electron , Microscopy, Fluorescence , Nerve Degeneration/genetics , Nerve Tissue Proteins/analysis , Neuroglia/pathology , Nuclear Receptor Subfamily 1, Group F, Member 1 , Olfactory Marker Protein , Olfactory Nerve/pathology , Receptors, Cytoplasmic and Nuclear/genetics , Trans-Activators/geneticsABSTRACT
The genes coding for class I glutathione S-transferases in insects were believed to be intronless because the coding sequence was not interrupted by an intron. But sequences of the untranslated 5' end of transcripts revealed the presence of an intron in housefly and Drosophila genes suggesting that most insect GSTI genes are in fact interrupted.
Subject(s)
Drosophila melanogaster/enzymology , Glutathione Transferase/genetics , Introns , Animals , Base Sequence , DNA, Complementary , Drosophila melanogaster/genetics , Molecular Sequence DataABSTRACT
We analysed Drosophila melanogaster cytochrome P450s (P450) through the measurements of four enzymatic activities: ethoxycoumarin-O-deethylase, ethoxyresorufin-O-deethylase, lauric acid hydroxylation, and testosterone hydroxylation. We did these measurements in two Drosophila strains: one is susceptible to insecticides (Cantons) and the other is resistant to insecticides by enhanced P450 activities (RDDTR). In addition, we also treated the flies with eight chemicals (beta-naphtoflavone, benzo-alpha-pyrene, 3-methylcholanthrene, phenobarbital, aminopyrine, rifampicin, prochloraz, and clofibrate) known to induces genes from the families CYP1, CYP2, CYP3, CYP4, and CYP6. Metabolisation of all the substrates by P450 from flies microsomes was observed. The chemicals had different effects on these activities, ranging from induction to inhibition. The effects of these chemicals varied with the strains as most of them were ineffective on the RDDTR strain. The results showed that P450-dependent activities are numerous in Drosophila. Regulation features of these activities are complex. The availability of mutant strains as RDDTR should allow fundamental studies of P450 in insects.
Subject(s)
Cytochrome P-450 Enzyme System/biosynthesis , Drosophila melanogaster/enzymology , Insecticide Resistance , Animals , Enzyme Induction , Hydroxylation , Lauric Acids/metabolism , Testosterone/metabolismABSTRACT
Human HepG2, rat Fao and MH1C1 hepatoma cell lines have been examined for their response to ciprofibrate, a potent peroxisome proliferator. Changes in the morphological characteristics of peroxisomes, the inductibility of their proliferation and of their beta-oxidation enzymes, palmitoyl-CoA oxidase and bifunctional enzyme, were studied in control and treated cells. In Fao cells, peroxisomes are less numerous and smaller than in rat liver, but they increase in size and number under the effect of ciprofibrate, similarly to those of treated rat liver. The high peroxisome proliferation is accompanied by a strong induction of beta-oxidation enzymes as in vivo. In MH1C1 cells, peroxisomes are seen in irregular clusters in the cytoplasm, small with rounded to tubular forms, suggesting rapid peroxisomal growth. A striking observation is the particularly elongated, worm-like form of many of the peroxisomes. Under the effect of ciprofibrate, the proliferation is low, as is the induction of beta-oxidation enzymes. HepG2 cells contain few, small peroxisomes with a heterogeneity of forms, from spherical to elongated. The only peroxisomal response to ciprofibrate in these cells seemed to be a morphological reorganization. There is little or no induction of beta-oxidation enzymes by ciprofibrate in HepG2 cells, as in cultured human hepatocytes. Therefore, on the one hand, Fao and MH1C1 cells are complementary tools in the investigation of the regulation of the hepatic response to peroxisome proliferators in the rat, on the other hand, HepG2 and Fao cells are useful in the study of the species specificity of the response.
Subject(s)
3-Hydroxyacyl CoA Dehydrogenases/metabolism , Clofibric Acid/analogs & derivatives , Enoyl-CoA Hydratase/metabolism , Hepatoblastoma/metabolism , Isomerases , Liver Neoplasms, Experimental/metabolism , Liver Neoplasms/metabolism , Liver/metabolism , Microbodies/drug effects , Multienzyme Complexes/metabolism , Oxidoreductases/metabolism , Animals , Cells, Cultured/drug effects , Clofibric Acid/pharmacology , Fenofibrate/pharmacology , Fibric Acids , Hepatoblastoma/ultrastructure , Humans , Liver/drug effects , Liver/ultrastructure , Liver Neoplasms/ultrastructure , Liver Neoplasms, Experimental/ultrastructure , Male , Microbodies/ultrastructure , Microscopy, Electron , Peroxisomal Bifunctional Enzyme , Rats , Rats, Wistar , Tumor Cells, Cultured/drug effectsABSTRACT
Studies were conducted between 1993 and 1996 using 3 natural grape vine populations, 1 susceptible laboratory strain, and 1 resistant selected strain of Drosophila melanogaster L. In vitro monooxygenase activity (ethoxycoumarine-O-deethylation) (ECOD) was recorded from microsomal fractions of all strains. Results varied over a 6-fold range between susceptible laboratory Canton and resistant selected RDDT strains and over a 2-fold range between the Canton strain and natural populations of flies. Few significant variations of ECOD activity were detected among the natural populations despite many insecticide treatments, but activities were significantly correlated with toxicological tolerance to 5 of the 15 insecticides (deltamethrin, fipronil, chlorpyriphos ethyl, DDT, and diazinon). Moreover, immunoblotting responses of microsomal protein encoded by Cyp6A2 showed that the levels of expression were quantitatively correlated with toxicological tolerance to almost the same group of insecticides (deltamethrin, fipronil, chlorpyriphos ethyl, DDT, fenvalerate, and fenthion). However, the level of CYP6A2 expression in some natural strains (still weakly resistant) was almost comparable with one of the resistant strains. In vivo monooxygenase activity recorded in individual abdomens of flies showed that frequency distributions of ECOD activity in natural populations overlapped those of the resistant and laboratory strains, which were much narrower. Substantial and fast frequency changes (of the narrowness) that obtained in laboratory were related to either the time of rearing of 1 of the natural populations or selecting this population with an insecticide that has a toxicology correlated with both of the monooxygenase signs measured. Perspectives on using the CYP6A2 expression and ECOD activity for detecting a resistance mechanism by cytochrome P450 in field populations are discussed.
Subject(s)
Cytochrome P-450 Enzyme System/metabolism , Drosophila melanogaster/enzymology , Insecticides , Animals , Blotting, Western , Cytochrome P-450 Enzyme System/biosynthesis , Cytochrome P450 Family 6 , Drosophila Proteins , Insecticide Resistance , Nitriles , Oxygenases/metabolism , Pyrethrins , RosalesABSTRACT
The gonad of Helix aspersa contains a factor which can stimulate in a dose-dependent manner galactogen synthesis in albumen gland explants cultured in vitro. The stimulatory activity appears to be greater when the gonad is predominantly male than when it is predominantly female. The albumen gland of virgin snails does not respond in vitro to the gonadal influence. The receptivity of the albumen gland to the galactogen synthesis stimulating effect of the gonad is increased after the first and second mating. It decreases at the third mating in correlation with the increase of the albumen gland maturation index.
Subject(s)
Galactans/biosynthesis , Helix, Snails/physiology , Animals , Female , Gonads/physiology , Male , Tissue Extracts/pharmacologyABSTRACT
AceIJ29 and AceIJ40 are cold- and heat-sensitive variants of the gene coding for acetylcholinesterase in Drosophila melanogaster. In the homozygous condition, these mutations are lethal when animals are raised at restrictive temperatures, i.e., below 23 degrees C for AceIJ29 or above 25 degrees C for AceIJ40. The coding regions of the gene in these mutants were sequenced and mutations changing Ser374 to Phe in AceIJ29 and Pro75 to Leu in AceIJ40 were found. Acetylcholinesterases bearing these mutations were expressed in Xenopus oocytes and we found that these mutations decrease the secretion rate of the protein most probably by affecting its folding. This phenomenon is exacerbated at restrictive temperatures decreasing the amount of secreted acetylcholinesterase below the lethality threshold. In parallel, the substitution of the conserved Asp248 by an Asn residue completely inhibits the activity of the enzyme and its secretion, preventing the correct folding of the protein in a non-conditional manner.
Subject(s)
Acetylcholinesterase/genetics , Drosophila melanogaster/genetics , Gene Expression Regulation, Enzymologic , Point Mutation , Acetylcholinesterase/metabolism , Amino Acid Sequence , Animals , Base Sequence , Cell Compartmentation , Cloning, Molecular , Cold Temperature , Conserved Sequence , Drosophila melanogaster/enzymology , Hot Temperature , Molecular Sequence Data , Oocytes/metabolism , Phenotype , Polymerase Chain Reaction , Protein Folding , Sequence Homology, Amino Acid , Xenopus/metabolismABSTRACT
Extensive utilization of pesticides against insects provides us with a good model for studying the adaptation of a eukaryotic genome to a strong selective pressure. One mechanism of resistance is the alteration of acetylcholinesterase (EC 3.1.1.7), the molecular target for organophosphates and carbamates. Here, we report the sequence analysis of the Ace gene in several resistant field strains of Drosophila melanogaster. This analysis resulted in the identification of five point mutations associated with reduced sensitivities to insecticides. In some cases, several of these mutations were found to be combined in the same protein, leading to different resistance patterns. Our results suggest that recombination between resistant alleles preexisting in natural populations is a mechanism by which insects rapidly adapt to new selective pressures.
Subject(s)
Acetylcholinesterase/chemistry , Acetylcholinesterase/genetics , Drosophila melanogaster/genetics , Insecticide Resistance/genetics , Insecticides/toxicity , Paraoxon/pharmacology , Point Mutation , Protein Structure, Secondary , Acetylcholinesterase/metabolism , Amino Acid Sequence , Animals , Binding Sites , Carbaryl/pharmacology , Cloning, Molecular , Drosophila melanogaster/drug effects , Drosophila melanogaster/enzymology , Female , Insecticides/pharmacology , Kinetics , Malathion/analogs & derivatives , Malathion/pharmacology , Models, Molecular , Oocytes/physiology , Propoxur/pharmacology , Torpedo , XenopusABSTRACT
Mitochondrial (mt) DNA of the phytophagous mite Tetranychus urticae was purified and a restriction map was constructed. The 12.5 kb long genome is the shortest animal mtDNA known. A 564 bp clone comprising part of the gene for cytochrome oxidase subunit I was sequenced. As has been found in insects, the mitochondrial sequences of mites are extremely A+T rich (75% on average, 96.5% at the third codon position).
Subject(s)
DNA, Mitochondrial/genetics , Electron Transport Complex IV/genetics , Genes , Mites/genetics , Animals , Molecular Sequence Data , Restriction Mapping , Sequence Homology , Subacute Sclerosing PanencephalitisABSTRACT
Quantitative and qualitative changes of acetylcholinesterase can affect the sensitivity of insects to insecticides. First, the amount of acetylcholinesterase in the central nervous system is important in Drosophila melanogaster, flies which overexpress the enzyme are more resistant than wild-type flies. On the contrary, flies which express low levels of acetylcholinesterase are more susceptible. An overproduction of acetylcholinesterase outside the central nervous system also protects against organophosphate poisoning, that is, flies producing a soluble acetylcholinesterase, secreted in the haemolymph, are resistant to organophosphates. Second, resistance can also result from a qualitative modification of acetylcholinesterase. Four mutations have been identified in resistant strains: Phe115 to Ser, Ileu199 to Val, Gly303 to Ala and Phe368 to Tyr. Each of these mutations led to a different pattern of resistance and combinations between these mutations led to highly resistant enzymes.
Subject(s)
Acetylcholinesterase/genetics , Cholinesterase Inhibitors/pharmacology , Drosophila melanogaster/enzymology , Insecticides/pharmacology , Organophosphorus Compounds , Acetylcholinesterase/metabolism , Animals , Drosophila melanogaster/genetics , Insecticide Resistance/genetics , Point MutationABSTRACT
Immunohistochemistry with a polyclonal antibody raised against human plasma fibronectin (Fn) was used to determine the localization of Fn in endometrial sections of guinea pig uteri isolated at the first, fourth, sixth, or tenth day of the estrous cycle. Immunoreactive Fn was constantly visualized in the endometrial stroma but absent from the epithelial layer. Fn was detected in the uterine lumen on the first or fourth day of the estrous cycle and was absent from the other sections. To determine the origin of this luminal Fn the ability of subcultured endometrial cells to produce Fn was tested, and the hormonal regulation of Fn secretion was studied. Cells were treated by estradiol alone or in association with progesterone, progesterone alone, or untreated. Whatever the hormonal treatment, stromal cells constantly secreted immunoreactive Fn into the culture medium. In the same way, the amount of Fn synthesized and basally secreted by epithelial cells was not affected by any hormonal treatments. However, Fn was found in the apical secretions of the untreated or estradiol-treated epithelial cells but was undetectable in the apical compartment when the epithelial cells were treated by progesterone alone or in association with estradiol. These results indicate that Fn is constitutively secreted by stromal cells and that subcultured epithelial cells of guinea pig endometrium secrete Fn from both their basal and apical membrane domains. However, the apical secretion of Fn is specifically suppressed by progesterone.
Subject(s)
Endometrium/metabolism , Fibronectins/metabolism , Progesterone/pharmacology , Animals , Cells, Cultured , Electrophoresis, Polyacrylamide Gel , Endometrium/chemistry , Endometrium/cytology , Epithelial Cells , Epithelium/chemistry , Epithelium/metabolism , Estradiol/pharmacology , Estrus , Female , Fibronectins/analysis , Guinea Pigs , Immunohistochemistry , Precipitin TestsABSTRACT
Quantitative and qualitative changes in acetylcholinesterase confer resistance to insecticides. We have constructed several Drosophila melanogaster strains producing various amounts of enzyme by P-mediated transformation. Toxicological analysis of these strains demonstrates that resistance to organophosphorus insecticides is correlated with the amount of acetylcholinesterase in the central nervous system. Resistance may also be qualitatively determined. Comparison of the Drosophila acetylcholinesterase gene between a resistant strain caught in the wild and a wild type susceptible strain only revealed one nucleotide transition resulting in the replacement of a phenylalanine by a tyrosine. Flies mutant for acetylcholinesterase and rescued with a minigene mutagenized for this same transition produced an altered enzyme which renders flies resistant to pesticides.
Subject(s)
Acetylcholinesterase/metabolism , Drosophila melanogaster/drug effects , Insecticide Resistance/genetics , Insecticides/pharmacology , Malathion/pharmacology , Acetylcholinesterase/genetics , Amino Acid Sequence , Animals , Base Sequence , Cloning, Molecular , Drosophila melanogaster/enzymology , Drosophila melanogaster/genetics , Genomic Library , Kinetics , Molecular Sequence Data , Mutagenesis, Site-Directed , Nervous System/enzymology , Oligodeoxyribonucleotides , Synapses/enzymology , Transformation, GeneticABSTRACT
1. The presence of insulin-like substances has been demonstrated by immunocytochemistry in the central nervous system of the snail Helix aspersa. 2. The immunopositivity has been observed especially in the large perikarya of the mesocerebral green cells [the cerebral green cells (CeGC) stained in green by the alcian blue:alcian yellow technique]. 3. The removal of either the mesocerebrum or the CeGC stops the growth of the snail and induces the increase of the glycogen content in the mantle edge. 4. Our results show the existence of insulin-like material in the neurosecretory cells. Previous data having demonstrated the presence of specific binding sites to insulin in the cephalic ganglia of Helix aspersa, one may suggest that insulin could play a neuromodulatory or a neurotransmittory role in the central nervous system and might control the growth.
Subject(s)
Central Nervous System/chemistry , Helix, Snails/chemistry , Insulin , Neuropeptides/analysis , Animals , Central Nervous System/growth & development , Cross Reactions , Glycogen/metabolism , Helix, Snails/growth & development , Hemolymph/chemistry , Immunoenzyme Techniques , Insulin/immunology , Neuropeptides/immunology , Neuropeptides/physiology , Neurosecretory Systems/chemistry , Neurosecretory Systems/physiology , Staining and LabelingABSTRACT
Two classes of glutathione transferases have been identified and purified from Musca domestica. The first, designated as GST1, migrates as a single band of 28 kDa in SDS-gel electrophoresis, and the second, designated as GST2, migrates as a 32-kDa band. Antisera prepared against each class have no immunological cross-reactivity, and heterodimeric associations between the two classes have not been detected. Each class is composed of several isoforms: GST1 is composed of forms with isoelectric points from 4 to 9, whereas all the forms of GST2 have acidic pI values. Screening of cDNA libraries yielded clones coding for GST1, and the gene was sequenced and expressed in Escherichia coli. The high activity found in an insecticide-resistant strain (Cornell R) is correlated with high level of GST1 transcript.