1,932 research outputs found
Maternal environment shapes the life history and susceptibility to malaria of Anopheles gambiae mosquitoes.
No full textBACKGROUND: It is becoming generally recognized that an individual's phenotype can be shaped not only by its own genotype and environmental experience, but also by its mother's environment and condition. Maternal environmental factors can influence mosquitoes' population dynamics and susceptibility to malaria, and therefore directly and indirectly the epidemiology of malaria. METHODS: In a full factorial experiment, the effects of two environmental stressors - food availability and infection with the microsporidian parasite Vavraia culicis - of female mosquitoes (Anopheles gambiae sensu stricto) on their offspring's development, survival and susceptibility to malaria were studied. RESULTS: The offspring of A. gambiae s.s. mothers infected with V. culicis developed into adults more slowly than those of uninfected mothers. This effect was exacerbated when mothers were reared on low food. Maternal food availability had no effect on the survival of their offspring up to emergence, and microsporidian infection decreased survival only slightly. Low food availability for mothers increased and V. culicis-infection of mothers decreased the likelihood that the offspring fed on malaria-infected blood harboured malaria parasites (but neither maternal treatment influenced their survival up to dissection). CONCLUSIONS: Resource availability and infection with V. culicis of A. gambiae s.s. mosquitoes not only acted as direct environmental stimuli for changes in the success of one generation, but could also lead to maternal effects. Maternal V. culicis infection could make offspring more resistant and less likely to transmit malaria, thus enhancing the efficacy of the microsporidian for the biological control of malaria
Microsatellite DNA variation and the genetic structure of Anopheles gambiae populations in Mali, West Africa
No full textFLP-mediated Intermolecular recombination in the Cytoplasm of Drosophila embryos.
No full textWe show that when a heat-shock-driven gene that encodes the yeast FLP recombinase is injected into preblastoderm Drosophila embryos, it promotes intermolecular recombination between two coinjected plasmids that bear the specific recombination target sequence, FRT. Minimal, 34-bp FRT sites in the two plasmids are sufficient for their cointegration. The reaction is efficient enough to produce detectable recombinants when one of the plasmids is present in as little as 1000 molecules per embryo. This is comparable to the concentration of unique chromosomal sites, raising the possibility that integration of injected plasmid DNA into FRT-bearing fly chromosomes may also be achievable. Since integrants might be stabilized against the reverse excision reaction if the recombinase could be provided in a sharp pulse, it is encouraging that efficient plasmid cointegration is also achieved when in vitro synthesized FLP RNA rather than DNA is injected into the embryos
FLP-mediated Intermolecular recombination in the Cytoplasm of Drosophila embryos.
No full textWe show that when a heat-shock-driven gene that encodes the yeast FLP recombinase is injected into preblastoderm Drosophila embryos, it promotes intermolecular recombination between two coinjected plasmids that bear the specific recombination target sequence, FRT. Minimal, 34-bp FRT sites in the two plasmids are sufficient for their cointegration. The reaction is efficient enough to produce detectable recombinants when one of the plasmids is present in as little as 1000 molecules per embryo. This is comparable to the concentration of unique chromosomal sites, raising the possibility that integration of injected plasmid DNA into FRT-bearing fly chromosomes may also be achievable. Since integrants might be stabilized against the reverse excision reaction if the recombinase could be provided in a sharp pulse, it is encouraging that efficient plasmid cointegration is also achieved when in vitro synthesized FLP RNA rather than DNA is injected into the embryos
Complement-like protein TEP1 is a determinant of vectorial capacity in the malaria vector Anopheles gambiae.
No full textFLP-mediated Intermolecular recombination in the Cytoplasm of Drosophila embryos.
No full textWe show that when a heat-shock-driven gene that encodes the yeast FLP recombinase is injected into preblastoderm Drosophila embryos, it promotes intermolecular recombination between two coinjected plasmids that bear the specific recombination target sequence, FRT. Minimal, 34-bp FRT sites in the two plasmids are sufficient for their cointegration. The reaction is efficient enough to produce detectable recombinants when one of the plasmids is present in as little as 1000 molecules per embryo. This is comparable to the concentration of unique chromosomal sites, raising the possibility that integration of injected plasmid DNA into FRT-bearing fly chromosomes may also be achievable. Since integrants might be stabilized against the reverse excision reaction if the recombinase could be provided in a sharp pulse, it is encouraging that efficient plasmid cointegration is also achieved when in vitro synthesized FLP RNA rather than DNA is injected into the embryos
The Drosophila zinc finger transcription factor CF2 is a myogenic marker downstream of MEF2 during muscle development
No full textThe Drosophila C-2-H-2-type zinc-finger transcription factor CF2 has been shown to regulate follicular cell fate determination during oogenesis. Here we show that CF2 is also expressed in the developing muscles of the embryo where it first appears at stage 12 at the time of skeletal myoblast fusion. Later it is expressed in all muscle lineages including skeletal, visceral and cardiac. Epistatic analysis showed that CF2 expression is dependent on the myogenic factor MEF2. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved.sponsorship: NCI NIH HHS|P01CA78582, NIGMS NIH HHS|GM57843status: Publishe
The transcriptional factor CF2 is a mediator of EGF-R-activated dorsoventral patterning in Drosophila oogenesis
No full textEstablishment of dorsoventral polarity during Drosophila oogenesis requires localized intercellular communication between the follicular cells and the oocyte. This is initiated by the transmission of a "dorsal signal" from the oocyte to the anterior dorsal follicle cells by the EGF receptor (EGF-R) pathway and is followed by transmission of a second signal from the ventral follicle cells back to the embryo. We show that the zinc finger transcription factor CF2 participates in these processes. CF2 is suppressed by EGF-R signaling in the anterior dorsal follicle cells. Altered expression patterns of CF2 result in specific dorsoventral patterning defects in egg chambers and in embryos, as demonstrated phenotypically and with molecular markers. CF2 appears to act as a repressor of dorsal follicle cell fates and specifically as a repressor of the rhomboid gene transcriptio
The Reproducibility of Lists of Differentially Expressed Genes in Microarray Studies
No full textReproducibility is a fundamental requirement in scientific experiments and clinical contexts. Recent publications raise concerns about the reliability of microarray technology because of the apparent lack of agreement between lists of differentially expressed genes (DEGs). In this study we demonstrate that (1) such discordance may stem from ranking and selecting DEGs solely by statistical significance (P) derived from widely used simple t-tests; (2) when fold change (FC) is used as the ranking criterion, the lists become much more reproducible, especially when fewer genes are selected; and (3) the instability of short DEG lists based on P cutoffs is an expected mathematical consequence of the high variability of the t-values. We recommend the use of FC ranking plus a non-stringent P cutoff as a baseline practice in order to generate more reproducible DEG lists. The FC criterion enhances reproducibility while the P criterion balances sensitivity and specificity
Le Corbeau et le Renard: 99 versions réinventées: Style d'exercices
No full textThis book represents a fascinating effort. At first I thought it was going to be a collection of various parodies of La Fontaine's FC. It is not that, but rather a creative presentation of some 97 different versions of La Fontaine created by the author. The first two versions are a French translation of the Greek prose of the most original FC text in the Aesopic manuscripts and then La Fontaine's verse. Thereafter the fun begins! The imagination and the execution of this project are both remarkable. Let me offer a sample of five approaches: (1) an acrostic, so that the opening letters of each verse spell "M Jean La Fontaine"; (2) a prose version after the manner of Balzac; (3) a scientific version needing more than a full page; (4) a tourist guide version; and (5) a rhyming version in English. T of C at the end. 136 pages. 5¼" x 8". Printed upon demand.Language note: FrenchNicolas Mille
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