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M M Green

Publications and source records attributed to M M Green.

At least 19 recordsLinked to original sources
PubMed1991

Mutations in the su(s) gene affect RNA processing in Drosophila melanogaster.

We have studied the effect of mutations in the suppressor of sable [su(s)] gene on P element-induced yellow alleles. Two independent mutations tested, y76d28 and y1#7, contain a 1.1-kilobase (kb) P element inserted in the 5' transcribed untranslated portion of the yellow gene. Sequences responsible for the y1#7 mutation are inserted in the same transcriptional orientation as yellow and cannot be processed by splicing, and this mutation is not suppressed by su(s) mutations. P element sequences are located in a transcriptional orientation opposite to that of the yellow gene in y76d28; these sequences can be spliced from a composite P element-yellow mRNA, resulting in low accumulation of a functional 1.9-kb yellow transcript. The levels of both the putative precursor P element-yellow RNA and the 1.9-kb yellow transcript increase in y76d28 su(s) flies, suggesting that mutations in su(s) do not affect the efficiency of splicing of the P element sequences. Analysis of y76d28 cDNAs isolated from flies carrying a wild-type or mutant su(s) gene demonstrates that the choice of splice junctions to process P element sequences is unchanged in these different backgrounds, suggesting that mutations in su(s) do not affect the selection of donor and acceptor splice sites. We propose that the su(s) protein functions to control the stability of unprocessed RNA during the splicing reaction.

Alleles↗
PubMed1991

Acute pelvic inflammatory disease after surgical sterilization.

STUDY OBJECTIVE: Physicians are very cognizant of the possibility of pregnancy after surgical sterilization, but the potential for acute pelvic inflammatory disease (PID) is thought to be rare. This study was undertaken to determine if upper tract PID occurred more frequently than previously reported in patients remote from surgical sterilization. DESIGN: Retrospective review of hospitalized patients with the primary discharge diagnosis of PID. SETTING: Urban, university hospital. PARTICIPANTS: Three hundred sixty-four hospitalized patients with the primary discharge diagnosis of PID over a six-year study period. MEASUREMENTS AND MAIN RESULTS: Patients' age; gynecologic histories and diagnoses; and laboratory, clinical, and surgical findings were noted. Twenty-three cases of acute PID were identified in 21 patients previously sterilized (6%). Nine of the 23 cases had systemic toxicity warranting surgical evaluation; 18 of the 23 cases were admitted from the emergency department. Mean statistical characteristics of the study group were age, 27.3 +/- 0.8 (SE) years; time interval from sterilization, 49.8 +/- 7.4 months; WBC 15,000 +/- 1,200; and temperature, 38.0 +/- 0.2 C. CONCLUSION: We conclude that acute PID may occur more frequently than previously reported in patients with prior surgical sterilization. An increased awareness of this entity is warranted.

Acute Disease↗
PubMed1991

Cloning and direct sequencing from lambda cDNA libraries using the polymerase chain reaction: suppressin and the vasopressin receptor as models.

A strategy using the polymerase chain reaction (PCR) to screen a lambda gt11 pituitary cDNA library for cDNAs encoding suppressin, a putative anti-proliferative protein, and a putative vasopressin receptor is described. The use of this technique will facilitate the demonstration of e.g. the presence of "neuropeptide receptors" on cells of the lymphoid system, confirming the concept of "shared ligands and receptors" by the neuroendocrine and the immune system. Neither of the genes encoding the proteins of the present study have previously been cloned. The PCR-screening procedure requires sequence information from the gene of interest which permits the generation of complementary primers. These primers are then used in combination with lambda phage primers complementary to regions flanking the cloning site in a PCR to amplify cDNAs derived from the gene of interest. This novel screening procedure yields cDNA related to the gene of interest, including the largest clone present in the library. To confirm the utility of this technique for cDNA libraries, the library was also screened using traditional cDNA hybridization techniques. The largest clone obtained by screening the cDNA library with PCR was the same as that obtained by the conventional technique. Thus, the results of these studies show that the PCR method can be used instead of more conventional means to screen cDNA libraries. Lastly, we describe a protocol for directly sequencing PCR-amplified DNA using the same primers that are used for amplification. The combined use of these two strategies permits cloning and sequencing of cDNAs from lambda cDNA libraries in a fraction of the time required using traditional screening techniques, but with identical results.

Animals↗
PubMed1991

Larvicidal activity of Tagetes minuta (marigold) toward Aedes aegypti.

The steam distilled oils of 3 species of marigold, Tagetes patula, T. erecta and T. minuta, were tested for larvicidal activity toward third instar Aedes aegypti; activity at 10 ppm was demonstrated only for T. minuta. The larvicidal property of the whole oil dispersed in water persisted for at least 9 days. The terpene, ocimenone, which is a part of the whole oil, was found to be larvicidal only at a higher concentration than the whole oil and to lose its activity within 24 h after dispersal in water. These results suggest a potential utilization of oil of T. minuta or its components for the control of Ae. aegypti and other species of mosquitoes.

Aedes↗
PubMed1990

Tissue-specific transcriptional enhancers may act in trans on the gene located in the homologous chromosome: the molecular basis of transvection in Drosophila.

The y2 mutation resulted from the insertion of the gypsy element into the X-linked yellow locus of Drosophila melanogaster. As a consequence of this insertion, transcriptional enhancers that control the expression of the yellow gene in the wings and body cuticle of adult flies are unable to act on the yellow promoter, resulting in a tissue-specific phenotype characterized by mutant coloration in these structures. Some yellow null alleles (yn) are able to complement the y2 phenotype giving rise to near wild type y2/yn females. The molecular structure of the yellow locus in complementing and noncomplementing mutations was determined by cloning and sequencing the various alleles examined. From the information obtained in these studies, we propose a model suggesting that the complementing wild type phenotype of y2/yn flies might be due to the ability of functional wing and body cuticle transcriptional enhancers located in the yn locus to act in trans on the promoter of the yellow gene found in the y2-containing chromosome. Furthermore, this transactivation is abolished by the presence of an intact promoter in cis, suggesting that promoter competition between the yellow genes located on each homolog precludes the activation in trans by transcriptional enhancers in favour of cis effects on their own promoter.

Alleles↗
PubMed1990

Immunomodulatory characteristics of a novel antiproliferative protein, suppressin.

We investigated the immunoregulatory properties of a recently described inhibitor of lymphocyte proliferation, suppressin (SPN). It was determined that preincubation of murine leukocytes with SPN enhances natural killer cell (NK) activity. In addition, SPN potentiates interferon-gamma (IFN-gamma) augmentation of NK activity. Furthermore, preincubation of murine leukocytes with SPN induces the production of IFN-alpha/beta. The IFN-alpha/beta produced is active in NK assays as well as vesicular stomatitis virus neutralization assays. In vivo, SPN increases the time of survival of C57BL/6 mice injected with EL-4 lymphoma cells. Interestingly, SPN inhibits immunoglobulin (IgA, IgG, and IgM) production in response to the mitogen, concanavalin A in a dose-dependent manner. Collectively, the above data indicate SPN may have numerous applications in clinical science including tumor surveillance and autoimmune diseases such as arthritis.

Animals↗
PubMed1979

Genetic instability in Drosophila melanogaster: tandem duplications as monitors of intrastrand exchange.

Two tandem duplications of the X chromosome associated with the white eye color locus are described. In heterozygous females both revert to a nonduplicated chromosome without detectable meiotic recombination. Clustering of revertants suggests the reversion event occurs in the germ line prior to meiosis. Similarly in males one duplication also reverts with clustering implying a premeiotic event. Revertant X chromosomes derived from males are either nonduplicated or deleted. Intrastrand exchange can account for some but not all revertants recovered.

Animals↗
PubMed1979

Genetic identification of dominant overproducing mutations: the Beadex gene.

A model system for the identification of presumptive overproducing mutations from among visible dominant mutations in D. melanogaster is described. An overproducing mutation is expected if a dominant mutation is readily reverted by gene deletion and if gene deletions suppress the expression of the original dominant mutation in flies heterozygous for the deletion. The Beadex (1:59.4) mutations are shown to satisfy these requirements, since a Bx dominant mutations is reverted by induced deletion [Df(Bx)/+) is wild type], and is also suppressed in trans by such a deletion [(Bx/Df)Bx) is wild type]. In addition, all 13 mutations recovered as Bx reversions or suppressors were associated with recessive held up (hdp) mutations allelic inter se, but not allelic to any known hdp gene. One such hdp mutations does not function as an independent dominant suppressor of Bx, is not always associated with Bx deletion, and in the latter situation is readily separable from Bx. We suggest that it functions as a Bx deletion, and may therefore represent the structural gene which is cis-regulated by the overproducing Bx mutations.

Chromosome Mapping↗
PubMed1979

Sensitivity of drosophila mutants to chemical carcinogens.

7 single-mutant and five double-mutant strains of Drosophila melanogaster were tested for their relative sensitivity to the chemical carcinogens: 1-acetylaminofluorene, benzo(alpha)pyrene, N-methyl-N'-nitro-N-nitrosoguanidine, 4-nitro quinoline-1-oxide and aflatoxin B1. Among the single mutants, mei-9a, mei-41D5 and mus(1)104D1 are hypersensitive to all 5 chemicals, whereas mus(1)107D1 is hypersensitive only to 4-nitroquinoline-1-oxide and is slightly sensitive to benzo(alpha)pyrene. The mei-9a mei-41D5 double-mutant is the most sensitive of 5 tested double-mutants which carry the mei-9a allele. When treated with 0.025 mM benzo(alpha)pyrene this double-mutant produces significantly more sex-linked recessive lethals and dominant lethals than does the control. Analysis of double-mutants reveals that the mei-9+ product functions in a different repair pathway of methyl methanesulfonate-induced damage than do the normal products of the mus(1)103, mus(1)104 and mus(1)107 loci. Our findings suggest that the sensitivity of Drosophila repair-deficient mutants could be exploited in screening for potential mutagens and carcinogens.

4-Nitroquinoline-1-oxide↗
PubMed1979

Mutagen-sensitive mutants in Drosophila melanogaster: effects on premutational damage.

Drosophila melanogaster males from a Basc stock were mutagenized with either X-rays, ethyl methanesulfonate (EMS), or nitrogen mustard (HN2). Groups of identically treated males were crossed to different types of female. Sex-linked recessive lethals were scored as a genetic end point. The females used were homozygous for X-chromosomal mutations (mus(1)101D1, mus(1)104D1, mei-9 or mei-41D5) which lead to defective DNA repair and which increase the mutagen sensitivity of larvae. Females from a white stock with normal DNA repair capacities served as controls. The premutational lesions induced in mature sperm are only processed after insemination by the maternal enzyme systems present in the oocytes. Differences in the efficiency of the processing of lesions can lead to maternal effects on the frequency of mutations recovered from mutagenized sperm. It was found that, with the exception of mus(1)104D1, all mutants analysed significantly modify the mutation fixation of one or more types of premutational lesions. The most drastic effect is found with the mus(1)101D1 stock in which HN2-induced DNA cross-links do not lead to sex-linked recessive lethals. It is assumed that mus(1)101D1 is defective in an early step of DNA cross-link repair. Our first set of data clearly demonstrates that the study of maternal effects in Drosophila is an efficient tool to analyse the in vivo function of repair mutations on chemically induced mutagenesis.

Animals↗
PubMed1979

Genetic instability in Drosophila melanogaster: the induction of specific chromosome 2 deletions by MR elements.

We describe the spontaneous induction of deletions by MR elements at the l(2)gl, net, pr and cn loci. The frequent induction of l(2)gl deletions mimics the high frequency of l(2)gl alleles found in wild populations of D. melanogaster. We suggest that these and other data that we present militate for the conclusion that, in the wild, autonomous MR elements occur and function as mutators. We contend that MR elements are not simply the by-products of hybridization between wild and laboratory strains.

Alleles↗