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201.
Inge Vercaeren Hilde Vanaken J. Van Dorpe Guido Verhoeven W. Heyns 《Cell and tissue research》1998,292(1):115-128
The expression of cystatin-related protein (CRP) and of the C3-component of prostatic-binding protein (PBP) during postnatal development of the rat was studied by Northern blotting, dot blot and in situ hybridisation, and by radioimmunoassay or immunoblotting. In intact male rats, very little or no PBP-C3 could be detected in the prostate at 10 days, but at 20 days there was already strong expression. By in situ hybridisation, the first expression of C3 mRNA was observed at 13 days in the prostate and at 22 days in the lacrimal gland. For CRP, this occurred at 16 and 22 days, respectively. Neither CRP nor C3 was expressed in prepubertal male rats castrated at day 1 or day 10 or in female rats. Androgen treatment of intact male animals did not advance the expression of both mRNAs in the prostate, but did so in the lacrimal gland with first expression of C3 at 19 instead of 22 days and of CRP at 13 instead of 22 days. Identical values were obtained in female rats. Androgen treatment of castrated adult male rats resulted in a more rapid and homogeneous secondary induction. Positive immunostaining for the androgen receptor (AR) was observed in the lacrimal gland at 7 days, but its concentration, estimated by immunoblotting, was still low at 10 days. Maximal levels, reached at 30 days, were markedly higher in male than in female rats. In conclusion, CRP and C3 are induced by androgens in prepubertal rats. The time point of induction, however, is probably determined by other tissue and differentiation-dependent factors in addition to androgens and the AR. 相似文献
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Several observations of the occurrence of PCB in marine organisms have been published since Jensen (1966) proved the presence of these compounds as pollutants in the environment. In the last years the occurrence in terrestrial animals, especially birds have been reported a.o. by Prestt & Moore (1970). 相似文献
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Aileen Berasategui Karolin Axelsson Göran Nordlander Axel Schmidt Anna‐Karin Borg‐Karlson Jonathan Gershenzon Olle Terenius Martin Kaltenpoth 《Molecular ecology》2016,25(16):4014-4031
The pine weevil (Hylobius abietis, Coleoptera: Curculionidae) is an important pest of conifer seedlings in Europe. Despite its economic importance, little is known about the composition of its gut microbial community and the role it plays in mediating the weevil's ability to utilize conifers as a food source. Here, we characterized the gut bacterial communities of different populations of H. abietis across Europe and compared them to those of other beetles that occupy similar ecological niches. We demonstrate that the microbial community of H. abietis is similar at higher taxonomic levels (family and genus) across locations in Europe, with Wolbachia as the dominant microbe, followed by Enterobacteria and Firmicutes. Despite this similarity, we observed consistent differences between countries and locations, but not sexes. Our meta‐analysis demonstrates that the gut bacterial community of the pine weevil is very similar to that of bark beetles that also exploit conifers as a food source. The Enterobacteriaceae symbionts of both host taxa are especially closely related phylogenetically. Conversely, the microbiota of H. abietis is distinct from that of closely related weevils feeding on nonconifer food sources, suggesting that the microbial community of the pine weevil is determined by the environment and may be relevant to host ecology. Furthermore, several H. abietis‐associated members of the Enterobacteriaceae family are known to contain genes involved in terpenoid degradation. As such, we hypothesize that the gut microbial community is important for the utilization of conifer seedlings as a food source, either through the detoxification of plant secondary metabolites or through the supplementation of essential nutrients. 相似文献
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Affinity, capacity and oxygen sensitivity of two different mechanisms for bicarbonate utilization in Ulva lactuca L. (Chlorophyta) 总被引:1,自引:0,他引:1
Ulva lactuca, collected on the west coast of Sweden at the end of May, was able to utilize the HCO3 ? pool of seawater only through extracellular dehydration via carbonic anhydrase, followed by uptake of the CO2 formed. A decrease in the CO2 supply via this mechanism resulted in the gradual development of an additional method of HCO3 ? utilization, namely a direct uptake of HCO3 ? . Photosynthesis could then be supported by either a ‘HCO3 ? dehydration mechanism’ or a ‘HCO3 ? uptake mechanism’. Through selective inhibition of either of these mechanisms, the physiological properties of the other could be assessed. These properties suggest that the HCO3 ? uptake mechanism of U. lactuca is important under conditions when low concentrations of inorganic C, high pH and high external O2 concentrations would limit photosynthesis supported by the HCO3 ? dehydration mechanism. Such conditions may occur during intense irradiation of the alga in rockpools or in shallow bays with low rates of water exchange. The results are discussed in relation to a possible coupling between mechanisms for inorganic C acquisition and cell structure (or even morphology) of green macroalgae. They also illustrate some necessary precautions when using Michaelis–Menten kinetics for estimations of Vmax and K1/2 values. 相似文献
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