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61.
62.
PAP- and GLD-2-type poly(A) polymerases are required sequentially in cytoplasmic polyadenylation and oogenesis in Drosophila 总被引:1,自引:0,他引:1
Benoit P Papin C Kwak JE Wickens M Simonelig M 《Development (Cambridge, England)》2008,135(11):1969-1979
Cytoplasmic polyadenylation has an essential role in activating maternal mRNA translation during early development. In vertebrates, the reaction requires CPEB, an RNA-binding protein and the poly(A) polymerase GLD-2. GLD-2-type poly(A) polymerases form a family clearly distinguishable from canonical poly(A) polymerases (PAPs). In Drosophila, canonical PAP is involved in cytoplasmic polyadenylation with Orb, the Drosophila CPEB, during mid-oogenesis. We show that the female germline GLD-2 is encoded by wispy. Wispy acts as a poly(A) polymerase in a tethering assay and in vivo for cytoplasmic polyadenylation of specific mRNA targets during late oogenesis and early embryogenesis. wispy function is required at the final stage of oogenesis for metaphase of meiosis I arrest and for progression beyond this stage. By contrast, canonical PAP acts with Orb for the earliest steps of oogenesis. Both Wispy and PAP interact with Orb genetically and physically in an ovarian complex. We conclude that two distinct poly(A) polymerases have a role in cytoplasmic polyadenylation in the female germline, each of them being specifically required for different steps of oogenesis. 相似文献
63.
John D. Perrine John P. Pollinger Benjamin N. Sacks Reginald H. Barrett Robert K. Wayne 《Conservation Genetics》2007,8(5):1083-1095
California is home to both the native state-threatened Sierra Nevada red fox (Vulpes vulpes necator), which historically inhabited high elevations of the Sierra Nevada and Cascade mountains, and to multiple low-elevation
red fox populations thought to be of exotic origin. During the past few decades the lowland populations have dramatically
expanded their distribution, and possibly moved into the historic range of the native high-elevation fox. To determine whether
the native red fox persists in its historic range in California, we compared mitochondrial cytochrome-b haplotypes of the only currently-known high-elevation population (n = 9 individuals) to samples from 3 modern lowland populations (n = 35) and historic (1911–1941) high-elevation (n = 22) and lowland (n = 7) populations. We found no significant population differentiation among the modern and historic high-elevation populations
(average pairwise F
ST = 0.06), but these populations differed substantially from all modern and historic lowland populations (average pairwise
F
ST = 0.52). Among lowland populations, the historic and modern Sacramento Valley populations were not significantly differentiated
from one another (F
ST = −0.06), but differed significantly from recently founded populations in the San Francisco Bay region and in southern California
(average pairwise F
ST = 0.42). Analysis of molecular variance indicated that 3 population groupings (mountain, Sacramento Valley, and other lowland
regions) explained 45% of molecular variance (F
CT = 0.45) whereas only 4.5% of the variance was partitioned among populations within these groupings (F
SC = 0.08). These findings provide strong evidence that the native Sierra Nevada red fox has persisted in northern California.
However, all nine samples from this population had the same haplotype, suggesting that several historic haplotypes may have
become lost. Unidentified barriers have apparently prevented gene flow from the Sacramento Valley population to other eastern
or southern populations in California. Future studies involving nuclear markers are needed to assess the origin of the Sierra
Nevada red fox and to quantify levels of nuclear gene flow. 相似文献
64.
Perrine Marcenac W. Robert Shaw Evdoxia G. Kakani Sara N. Mitchell Adam South Kristine Werling Eryney Marrogi Daniel G. Abernathy Rakiswend Serge Yerbanga Roch K. Dabir Abdoulaye Diabat Thierry Lefvre Flaminia Catteruccia 《PLoS pathogens》2020,16(12)
Anopheles mosquitoes have transmitted Plasmodium parasites for millions of years, yet it remains unclear whether they suffer fitness costs to infection. Here we report that the fecundity of virgin and mated females of two important vectors—Anopheles gambiae and Anopheles stephensi—is not affected by infection with Plasmodium falciparum, demonstrating that these human malaria parasites do not inflict this reproductive cost on their natural mosquito hosts. Additionally, parasite development is not impacted by mating status. However, in field studies using different P. falciparum isolates in Anopheles coluzzii, we find that Mating-Induced Stimulator of Oogenesis (MISO), a female reproductive gene strongly induced after mating by the sexual transfer of the steroid hormone 20-hydroxyecdysone (20E), protects females from incurring fecundity costs to infection. MISO-silenced females produce fewer eggs as they become increasingly infected with P. falciparum, while parasite development is not impacted by this gene silencing. Interestingly, previous work had shown that sexual transfer of 20E has specifically evolved in Cellia species of the Anopheles genus, driving the co-adaptation of MISO. Our data therefore suggest that evolution of male-female sexual interactions may have promoted Anopheles tolerance to P. falciparum infection in the Cellia subgenus, which comprises the most important malaria vectors. 相似文献
65.
D Barbier D Perrine C Duhamel R Doublet P Georges 《Applied and environmental microbiology》1990,56(5):1420-1422
A modification of the FAUST technique allowed a highly regular recovery of Taenia saginata eggs from sewage sludge, as well as their quantification. Despite the low viability (8%) noted, the viable T. saginata egg level remains high (20.10(6)/ha) and offers a serious risk for cattle even after a 3-week "no-grazing" period. 相似文献
66.
Expression patterns of nm23 genes during mouse organogenesis 总被引:2,自引:0,他引:2
Nucleoside di-phosphate kinase enzyme (NDPK) isoforms, encoded by the nm23 family of genes, may be involved in various cellular differentiation and proliferation processes. We have therefore analyzed
the expression of nm23-M1, -M2, -M3, and -M4 during embryonic mouse development. In situ hybridization data has revealed the differential expression of nm23 mRNA during organogenesis. Whereas nm23-M1 and -M3 are preferentially expressed in the nervous and sensory systems, nm23-M2 mRNA is found ubiquitously. Irrespective of the developmental state studied, nm23-M4 mRNA is only expressed at low levels in a few embryonic organs. In the cerebellum and cerebral cortex, nm23-M1, -M2, and -M3 are present in the neuronal differentiation layer, whereas nm23-M4 mRNA is distributed in the proliferating layer. Thus, nm23 mRNA is differentially expressed, and the diverse NDPK isoforms are sequentially involved in various developmental processes. 相似文献
67.
Distinct post-transcriptional modifications result into seven alternative transcripts of the CC–NBS–LRR gene JA1tr of Phaseolus vulgaris 总被引:1,自引:0,他引:1
68.
Physiochemical properties of the Vi antigen before and after mild alkaline hydrolysis 总被引:4,自引:1,他引:3 下载免费PDF全文
Sedimentation and diffusion constants were determined for electrophoretically purified Vi antigen before and after mild alkaline hydrolysis. The molecular weight of the intact antigen was found to be 1.7 × 106. Mild alkaline hydrolysis completely removed O-acetyl, reduced the molecular weight to 1.0 × 105, and lowered the intrinsic viscosity from 8.0 deciliters/g to approximately 0.5 deciliter/g. Infrared spectra of the two antigen preparations were also compared. 相似文献
69.
Perrine Cruaud Adrien Vigneron Céline Lucchetti-Miganeh Pierre Emmanuel Ciron Anne Godfroy Marie-Anne Cambon-Bonavita 《Applied and environmental microbiology》2014,80(15):4626-4639
Next-generation sequencing (NGS) opens up exciting possibilities for improving our knowledge of environmental microbial diversity, allowing rapid and cost-effective identification of both cultivated and uncultivated microorganisms. However, library preparation, sequencing, and analysis of the results can provide inaccurate representations of the studied community compositions. Therefore, all these steps need to be taken into account carefully. Here we evaluated the effects of DNA extraction methods, targeted 16S rRNA hypervariable regions, and sample origins on the diverse microbes detected by 454 pyrosequencing in marine cold seep and hydrothermal vent sediments. To assign the reads with enough taxonomic precision, we built a database with about 2,500 sequences from Archaea and Bacteria from deep-sea marine sediments, affiliated according to reference publications in the field. Thanks to statistical and diversity analyses as well as inference of operational taxonomic unit (OTU) networks, we show that (i) while DNA extraction methods do not seem to affect the results for some samples, they can lead to dramatic changes for others; and (ii) the choice of amplification and sequencing primers also considerably affects the microbial community detected in the samples. Thereby, very different proportions of pyrosequencing reads were obtained for some microbial lineages, such as the archaeal ANME-1, ANME-2c, and MBG-D and deltaproteobacterial subgroups. This work clearly indicates that the results from sequencing-based analyses, such as pyrosequencing, should be interpreted very carefully. Therefore, the combination of NGS with complementary approaches, such as fluorescence in situ hybridization (FISH)/catalyzed reporter deposition (CARD)-FISH or quantitative PCR (Q-PCR), would be desirable to gain a more comprehensive picture of environmental microbial communities. 相似文献
70.
Philippe Icard Perrine Kafara Jean-Marc Steyaert Laurent Schwartz Hubert Lincet 《生物化学与生物物理学报:癌评论》2014
Cancer cells cooperate with stromal cells and use their environment to promote tumor growth. Energy production depends on nutrient availability and O2 concentration. Well-oxygenated cells are highly proliferative and reorient the glucose metabolism towards biosynthesis, whereas glutamine oxidation replenishes the TCA cycle coupled with OXPHOS-ATP production. Glucose, glutamine and alanine transformations sustain nucleotide and fatty acid synthesis. In contrast, hypoxic cells slow down their proliferation, enhance glycolysis to produce ATP and reject lactate which is recycled as fuel by normoxic cells. Thus, glucose is spared for biosynthesis and/or for hypoxic cell function. Environmental cells, such as fibroblasts and adipocytes, serve as food donors for cancer cells, which reject waste products (CO2, H+, ammoniac, polyamines…) promoting EMT, invasion, angiogenesis and proliferation. This metabolic-coupling can be considered as a form of commensalism whereby non-malignant cells support the growth of cancer cells. Understanding these cellular cooperations within tumors may be a source of inspiration to develop new anti-cancer agents. 相似文献