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5S-rRNA genes in rice embryos   总被引:3,自引:0,他引:3  
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Decreased GLUT4 expression and impaired GLUT4 cell membrane translocation are involved in type 2 diabetes mellitus (T2DM) pathogenesis so the factors impacting GLUT4 expression may be associated with T2DM. In this study, we identified four miRNAs: miR-31, miR-93, miR-146a, and miR-199a which suppress GLUT4 expression in HEK293T cells. Subsequently, we determined expression of these four miRNAs in plasma samples of T2DM patients, T2DM susceptible individuals, and healthy controls and found miR-199a was overexpressed in patients’ plasma compared with healthy control. Because the miR-199a binding site in GLUT4 3′UTR is highly conserved among vertebrates, we detected the glucose uptake in rat L6 myoblast cells through gain- and loss-of-function of miR-199a. We found that miR-199a can repress glucose uptake in L6 cells, which was rescued by GLUT4 overexpression. These results indicate that T2DM patients may have a high level miR-199a that reduce GLUT4 expression and contribute to the insulin resistance. Hence, miR-199a may be a novel biomarker for risk estimation and classification in T2DM patients.  相似文献   

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A quantitative polyacrylamide gel electrophoresis procedure for the analysis of microgram quantities of RNA has been developed. The method was used to determine the rates of rRNA synthesis and the molar ratios of various RNA species in Drosophila females homozygous for either of two X chromosome inversions that result in sterility of the females and produce lethality in X/0 males. Evidence is presented that in these genotypes the rate of rRNA synthesis during oogenesis is unimpaired but the mature oocyte has a 10–12% reduction in rRNA content.  相似文献   

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Early biological control attempts ofDiatraea saccharalis in Barbados had failed. Subsequent intensive release campaigns of several parasite species from the Neotropics. Africa and India resulted in the temporary establishment ofMetagonistylum minense andTrichogramma japonicum and the permanent establishment ofLixophaga diatraeae andApanteles flavipes. The latter built up an extraordinarily high population level within a short period of time. From damage assessments it is evident that due to high parasitism crop damage was reduced considerably. The joint borer infestation which fluctuated around 15% until 1966 decreased to less than 6% in 1970.
Résumé Des essais de lutte biologique contreDiatraea saccharalis ont été poursuivis à la Barbade pendant plus de 40 ans. Des libérations en masse deTrichogramma japonicum, faites jusqu’en 1958, se révélèrent infructueuses; la mouche de Cuba,Lixophaga diatraeae, fut introduite au début de l’année 1960, mais sa répartition demeura inégale et sa fréquence généralement faible jusqu’en 1968, date à laquelle elle se répandit soudain dans toute l’?le et augmenta en abondance (moyenne de parasitisme en 1968: 13,6%). Tout s’est passé comme si, durant les années précédentes, une race s’était développée qui est maintenant mieux adaptée aux conditions environnantes de la Barbade. En 1966 et 1967, plusieurs autres espèces de parasites furent introduites à la Barbade. Parmi elles,Metagonistylum minense etTrichogramma fasciatum s’établirent temporairement, tandis queApanteles flavipes, introduite des Indes, s’acclimata d’elle-même en permanence. A la suite d’une libération d’environ 2 000 individus en juillet et ao?t 1966, ce parasite fut retrouvé pour la première fois, plus d’un an après, en octobre 1967; à la fin de 1969, il avait colonisé toute l’?le avec un taux de parasitisme de 0,5 à 95,5% et en moyenne de 30,3%. Ces deux dernières années, la réduction des dégats a produit une augmentation de revenu estimée à 315 000 et 405 000 £, respectivement.


Presented at the symposium OILB on borers of graminaceous plants. Paris, 24th sept. 1970.  相似文献   

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Levels of immunoglobulins were determined in persons exposed to high altitude. The individuals studied included high altitude natives, sea level residents at high altitude for 2 years, and recent arrivals at high altitude. Increased IgG and IgA levels were found in high altitude natives and sea level residents at high altitude for 2 years when compared with sea level residents. In recent arrivals marked increase of IgG and IgG levels and slight rise in IgM was seen. Recent arrivals who suffered from high altitude pulmonary oedema showed marked elevation of IgG, IgM, and IgA. Immunoglobulin responses to both primary and secondary TAB inoculation were of a higher magnitude and more sustained at high altitude than at sea level.  相似文献   

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The intracellular levels of ppGpp and pppApp in various microorganisms were determined by radioimmunoassay, with was of more accuracy and convenience than previous 32P-labeling method. ppGpp was detected in bacteria, actinomycetes, yeasts and fungi. pppApp was found in non-spore forming bacteria such as the genera Pseudomonas and Escherichia, fungi and actinomycetes, but not in yeasts. In conclusion, ppGpp and pppApp are present in various prokaryotes and lower eukaryotes.  相似文献   

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Adrian P. Bird 《Chromosoma》1974,46(4):421-433
A technique for the isolation of very high molecular weight rDNA1 from the ovary of Xenopus laevis is described. Tritiated rDNA was prepared by this method from ovaries at the amplification stage, and spread on slides for light microscope autoradiography. The average molecular weight of the spread DNA was greater than 180×106 daltons. Unlike chromosomal DNA grain tracks, rDNA tracks after 2 or 4 hours of labelling were not tandemly arranged. By allowing ovaries to equilibrate gradually with exogenous precursors, tracks showing a single gradient of grain density were produced, indicating that replication was proceeding in one direction at these sites. Bidirectional initiations, if they occur at all during amplification, are rare. The rate of rDNA chain growth is 10.5 μ/hour at 23° C, which is the same as the rate for chromosomal DNA synthesis in X. laevis. After 24 hours some tracks are over 200 μ long, suggesting that replication at a site may be continuous for at least this period. Although they do not distinguish between several alternative mechanisms, the results are compatible with a rolling circle mechanism for gene amplification.  相似文献   

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Incidence of parasites ofLymantria obfuscata Walker [Lymantriidae: Lepidoptera] was studied in Kashmir during 1983 and 1984. The only egg parasite reared wasAnastatus kashmirensis Mathur parasitising between 4.49 to 11.92 percent of eggs. From 15 study sites as many as 10475 larvae of different stages and pupae were collected and reared in laboratory.Exorista rossica [Tachinidae: Diptera] was recorded to parasitize upto 8.42 per cent of larvae compared to 0.89 percent byCompsilura sp.Tetrastichus sp. [Eulophidae: Hymenoptera] was observed to be most dominant of the 6 pupal parasites, accounting for 33.41 percent of the measured parasitism, followed byPimpla sp. [Ichneumonidae: Hymenoptera] andTheronia atalantae atalantae [Ichneumonidae: Hymenoptera] which parasitized 6.84 and 4.03 per cent of pupae respectively.Brachymeria intermedia Nees [Chalcididae: Hymenoptera] was recorded to parasitize upto 2.98 per cent whereasBrachymeria lasus Walker recorded for the first time in Kashmir was found to parasitize up to 2.01 per cent, but was not widely distributed in the State.  相似文献   

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This study was performed in order to delineate differences in kinetic enzyme characteristics of brain monoamine oxidase (MAO) and plasma cholinesterase (ChE) derived from the Walker-Walker (Fawn Hooded, FH) rat and from its putative ancestors, the Wistar (W) and Long-Evans (LE). As compared with the enzyme isolated from the other two strains, brain MAO from FH has both a higher V max and increased reaction rate at lower substrate concentrations. It may thus be described as a “more efficient” enzyme. This study confirms previous work which shows that plasma ChE activity of females is higher than that of males. Fluoride ion is a noncompetitive inhibitor of the Wistar ChE, is a competitive inhibitor of the FH enzyme, and has no effect on the LE enzyme. Dibucaine is a competitive inhibitor in all cases except one: ChE derived from the FH female is uncompetitively inhibited. A comparison of the inhibitor constants shows that FH ChE is more resistant to Dibucaine than is that of W, and that LE is the most sensitive. FH cholinesterase is twice as resistant to the action of fluoride as is the Wistar enzyme.  相似文献   

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InCallithrix, Saguinus, Aotus, andCallicebus other group members than the mother participate in infant care. Differences among these species are obvious in respect to the time of being off any caregiver, and in respect to the carrying position (Aotus andCallicebus). Alloparental care, a basic behaviour pattern in these species, has evolved from the parking behaviour of the prosimians. The infants are «parked» at other group members.  相似文献   

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