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121.
CHILL-COMA TOLERANCE, A MAJOR CLIMATIC ADAPTATION AMONG DROSOPHILA SPECIES   总被引:1,自引:1,他引:1  
Abstract.— Most drosophilid species can be classified either as temperate or tropical. Adults of species were submitted to a cold treatment (0°C) and then brought back to ambient temperature. They generally exhibited a chill coma and the time needed to recover was measured. We found in a set of 26 temperate species that recovery was rapid (average 1.8 min, range 0.15–4.9). In contrast, a long recovery time (average 56 min, range 24–120) was observed for 48 tropical species. A few species, like Drosophila melanogaster, are cosmopolitan and can proliferate under temperate and tropical climates. In 9 of 10 such species, slight genetic differences were found: a shorter recovery in temperate than in tropical populations. Comparing physiological data to phylogeny suggests that chill‐coma tolerance has been a recurrent adaptation that is selected for in cold climates but tends to disappear under a permanently warm environment. This major climatic adaptation, evidenced in drosophilids, seems to occur in other insect groups also.  相似文献   
122.
Zaprionus indianus is a cosmopolitan drosophilid, of Afrotropical origin, which has recently colonized South America. The sexual dimorphism (SD) of body size is low, males being almost as big as females. We investigated 10 natural populations, 5 from America and 5 from Africa, using the isofemale line technique. Three traits were measured on each fly: wing and thorax length and sternopleural bristle number. Two indices of SD were compared, and found to be highly correlated (r > 0.99). For the sake of simplicity, only the female/male (F/M) ratio was further considered. A significant genetic variability of SD was found in all cases, although with a low heritability (intra-class correlation of 0.13), about half the value found for the traits themselves. For size SD, we did not find any variation among continents or any latitudinal trend, and average values were 1.02 for wing length and 1.01 for thorax length. Bristle number SD was much greater (1.07). Among mass laboratory strains, SD was genetically much more variable than in recently collected populations, a likely consequence of laboratory drift. Altogether, SD, although genetically variable and prone to laboratory drift, is independent of size variations and presumably submitted to a stabilizing selection in nature.  相似文献   
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124.
Adoptive therapy for cancer using tumor-infiltrating lymphocytes (TIL) has mainly been investigated in cancer patients with advanced stage disease. The limited clinical success has not been encouraging, although this might be explained by poor TIL specificity and/or high tumor burden. To re-evaluate the effectiveness of adoptive therapy, we analyzed the capacity of tumor-reactive TIL injection in preventing the further development of disease in stage III melanoma patients after complete tumor resection. A phase II/III randomized trial was performed on 88 melanoma patients, who received autologous TIL plus interleukin-2 (IL-2) or IL-2 only. The duration of relapse-free survival was analyzed, taking into account the immunological specificity of injected TIL and the number of metastatic lymph nodes removed before treatment. Kaplan-Meyer analysis revealed that the injection of tumor-reactive TIL was statistically correlated with prolonged relapse-free survival in patients with only one metastatic lymph node. Therefore, improved clinical outcome could be obtained after adoptive therapy by selecting appropriate groups of patients and monitoring the specificity of the injected TIL populations.  相似文献   
125.
GGGGCC (G4C2) repeat expansion in the C9orf72 gene has been shown to cause frontotemporal lobar degeneration and amyotrophic lateral sclerosis. Dipeptide repeat proteins produced through repeat-associated non-AUG (RAN) translation are recognized as potential drivers for neurodegeneration. Therefore, selective inhibition of RAN translation could be a therapeutic avenue to treat these neurodegenerative diseases. It was previously known that the porphyrin TMPyP4 binds to G4C2 repeat RNA. However, the consequences of this interaction have not been well characterized. Here, we confirmed that TMPyP4 inhibits C9orf72 G4C2 repeat translation in cellular and in in vitro translation systems. An artificial insertion of an AUG codon failed to cancel the translation inhibition, suggesting that TMPyP4 acts downstream of non-AUG translation initiation. Polysome profiling assays also revealed polysome retention on G4C2 repeat RNA, along with inhibition of translation, indicating that elongating ribosomes stall on G4C2 repeat RNA. Urea-resistant interaction between G4C2 repeat RNA and TMPyP4 likely contributes to this ribosome stalling and thus to selective inhibition of RAN translation. Taken together, our data reveal a novel mode of action of TMPyP4 as an inhibitor of G4C2 repeat translation elongation.  相似文献   
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Phloem sieve elements are highly differentiated cells involved in the long-distance transport of photoassimilates. These cells contain both aggregated phloem-proteins (P-proteins) and soluble proteins, which are also translocated by mass flow. We used liquid chromatography-tandem mass spectrometry (LC-MS/MS) to carry out a proteomic survey of the phloem exudate of Arabidopsis thaliana, collected by the ethylenediaminetetraacetic acid (EDTA)-facilitated method. We identified 287 proteins, a large proportion of which were enzymes involved in the metabolic precursor generation and amino acid synthesis, suggesting that sieve tubes display high levels of metabolic activity. RNA-binding proteins, defence proteins and lectins were also found. No putative P-proteins were detected in the EDTA-exudate fraction, indicating a lack of long-distance translocation of such proteins in Arabidopsis. In parallel, we investigated the organization of P-proteins, by high-resolution transmission electron microscopy, and the localization of the phloem lectin PP2, a putative P-protein component, by immunolocalization with antibodies against PP2-A1. Transmission electron microscopy observations of P-proteins revealed bundles of filaments resembling strings of beads. PP2-A1 was found weakly associated with these structures in the sieve elements and bound to plastids. These observations suggest that PP2-A1 is anchored to P-proteins and organelles rather than being a structural component of P-proteins.  相似文献   
128.
Vertebrate remains and nummulites have been investigated from the Late Eocene—Early Oligocene transgressive sequence of the «Chaînes subalpines south of the lake Annecy. The sedimentary environments range from fluvio-lacustrine shales and conglomerates at the base to hemipelagic Globigerina shales at the top. The fluvio-lacustrine white marls contain mammals of the upper, probably terminal Ludian, with affinities to the assemblage of Saint-Capraise. The brackish Cerithium beds have furnished charophytes of the Bembridge zone. The nummulite limestones are not dated precisely, but isolated, probably redeposited nummulites from the base of the Globigerina shales are of terminal Eocene or basal Oligocene age. The Globigerina shales themselves belong to the Oligocene.  相似文献   
129.
Dlmo基因编码一个32kDa的蛋白   总被引:1,自引:0,他引:1  
朱天慧  秦刚  张立冬  刘志霈  张杰 《遗传》2001,23(1):21-24
为了获取研究Dlmo(果蝇LMO基因的简称)的功能信息,使用耦联网织红细胞体外翻译系统将Dlmo基因进行体外转录翻译得到32kDa的蛋白产物。该蛋白产物与抗人类LMO2蛋白的多抗抗体发生免疫沉淀,并得到了32kDa的阳性带。为了证实Dlmo基因在体外和体内翻译能得到同一大小蛋白,从2~4小时果蝇胚盘中分别抽提核和胞浆提取物进行Western印迹分析,免疫血清可以识别胞浆提取物中的32kDa蛋白,而在核提取物中未曾见到,证实体外和体内翻译产物相同。免疫组织化学的分析在0~4小时胚盘外周胞浆中有Dlmo基因的阳性染色信号,结果证实,Dlmo与人类LMO不同,其表达产物是一个胞浆蛋白。 Abstract:In order to gain some insight into a possible function of Dlmo gene,we used the TNT coupled reticulocyte lysate systems as an in vitro translation system to detect the Drosoplila protein. We found a 32kDa protein product.To demonstrate that the DLMO protein has the same size in vivo as in vitro we studied nuclear and cytoplasmic extracts from 2-4h embryos in Western blots. The immuno serum recognizes a 32kDa protein in the cytoplasm that is not present in the nucleus.The products were immune precipitated with the polyclonal anti-LMO2 antibody raised against the human protein and seen a positive band of 32kDa.Using immuno histochemical analysis was seen a positive staining in the basal cytoplasm of blastoderm embryos at 4 hours. This result confirms that the DLMO is a cytoplasmprotein, not like human LMO protein.  相似文献   
130.

Introduction  

Phosphatidylcholine and phosphatidylcholine-derived metabolites exhibit anti-inflammatory properties in various stress conditions. We hypothesized that dietary phosphatidylcholine may potentially function as an anti-inflammatory substance and may decrease inflammatory activation in a chronic murine model of rheumatoid arthritis (collagen-induced arthritis).  相似文献   
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