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1.
Sandra Danner Christiane Kirchhoff Richard Ivell 《Reproductive biology and endocrinology : RB&E》2009,7(1):67-14
Background
Post-meiotically expressed genes in the testis are essential for the proper progression of spermatogenesis, and yet, aside from the construction of individual transgenic mice using specific promoters to drive reporter plasmids, there are only very limited possibilities for relevant and quantitative analysis of gene promoters. This is due to the special nature of post-meiotic haploid cells, which to date are not represented in any appropriate cell-lines. This article reports the development of novel methodology using isolated and cultured rat seminiferous tubules in a multiwell format, into which promoter-reporter constructs can be introduced by a combination of microinjection and electroporation. 相似文献2.
The ultrastructure and distribution of receptor cells near the mouth and (where present) the pharynx of Hofstenia miamia, Proporus bermudensis, Conaperta thela, and Convoluta convoluta (Acoela) were investigated by transmission electron microscopy and confocal laser scanning microscopy of specimens stained with a fluorescence marker for actin. Five types of monociliary receptors were identified: (1) non‐collared receptors with a single long and narrow ciliary rootlet; (2) non‐collared receptors with a wide main ciliary rootlet and a smaller posterior rootlet; (3) non‐collared receptors with a single wide and hollow ciliary rootlet with a granulated core; (4) Collar (?) receptors with obliquely radial filament bundles in the cell apex and with a single hollow ciliary rootlet composed of numerous strand‐like elements; and (5) Collar receptors lacking a striated rootlet but with a granular body (swallow's nest rootlet). While H. miamia bears the first two receptor types, P. bermudensis has receptors of type 1, 3 and 5, and Cona. thela and Conv. convoluta have receptors of type 3, 4 and 5. The density of receptors is generally highest at the anterior body tip, regardless of where the mouth is located. Most receptor types occur scattered over the whole body but type 2 receptors of H. miamia are restricted to the pharynx and mouth region. The lack of a common receptor type specific for the mouth and pharynx of the investigated species points to an independent origin of the pharynges in Hofsteniidae and in Proporidae and of the mouth tube in Convolutidae. Moreover, the homology of the so‐called collar receptors in Acoela with typical collar receptors in other invertebrates is questioned. 相似文献
3.
Specific binding of atrial natriuretic factor to renal glomeruli in Doca- and Doca-salt-treated rats correlation with atrial and plasma levels 总被引:2,自引:0,他引:2
G Gauquelin E L Schiffrin M Cantin R Garcia 《Biochemical and biophysical research communications》1987,145(1):522-531
Since volume expansion and high blood pressure (BP) are known stimuli of atrial natriuretic factor (ANF) release, and since this peptide may be involved in mineralocorticoid escape, we investigated the effects of chronic deoxycorticosterone (DOCA) and DOCA-NaC1 treatment on renal glomerular ANF receptor density and affinity in relation to atrial and plasma ANF levels. An increase in plasma immunoreactive ANF (IR-ANF) was observed both after two and four weeks of treatment. IR-ANF concentrations were elevated in the left atrium only in four-week DOCA treated rats. Administration of the mineralocorticoid alone resulted in a decreased density of glomerular ANF receptors in both time periods investigated. DOCA-NaC1-treated animals presented an increased receptor density during the pre-hypertensive stage (2 weeks) and a reduced density in the later hypertensive period (4 weeks). Receptor affinity in both groups was identical to that in the controls after 2 weeks and was augmented after 4 weeks of treatment. Our data suggest that the down-regulation of renal glomerular ANF receptors during chronic DOCA-NaC1 administration may play a role in the maintenance of high BP in this model of volume-expanded hypertension. 相似文献
4.
Hans-Jürgen Peter Christiane Krüger-Alef Wolfgang Knogge Klaus Brinkmann Gottfried Weissenböck 《Planta》1991,183(3):409-415
Chalcone-synthase (CHS) activity was followed during the development of primary leaves of oat (Avena sativa L.) seedlings grown under different illumination conditions. Continuous darkness and continuous light resulted in similar time courses of enzyme activity. The maximum of CHS activity in etiolated leaves was delayed by 1 d and reached about half the level of that of light-grown leaves. In seedlings grown under defined light-dark cycles a diurnal rhythm of CHS activity and its protein level was observed which followed the rhythm of CHS-mRNA translational activity (Knogge et al. 1986). This rhythm persisted in continuous light after a short-term pre-exposure to the light-dark cycle but not in continuous darkness.Abbreviations CHS
chalcone synthase
- PAL
phenylalanine ammonio lyase
Financial support by the Deutsche Forschungsgemeinschaft is gratefully acknowledged (G.W., We 630/9-7; We 630/10-1). Thanks are given to Dr. St. Kellam (Department of Plant Microbiological Sciences, University of Canterbury, New Zealand) for correcting the English. 相似文献
5.
R Garcia M Cantin A De Léan J Genest J Godin J Gutkowska E L Schiffrin G Thibault 《Biochemical and biophysical research communications》1986,135(3):987-993
The biological activities of ANF (Arg 101-Tyr 126) and of the circulating form, ANF (Ser 99-Tyr 126), were compared in the following assays: precontracted rabbit aortic strip and chick rectum, rat natriuresis, inhibition of aldosterone secretion and receptor affinity in bovine and rat adrenal zona glomerulosa cells, and receptor affinity in rabbit aorta and rat mesenteric artery cells. The results demonstrate that both peptides share the same biological activities. It is concluded that the addition of two amino acids to the N-terminal of ANF (Arg 101-Tyr 126) does not modify its biological characteristics, validating thus previous research employing this peptide. 相似文献
6.
7.
Edmond A. Goidl Christiane Samarut Ansbert Schneider-Gadicke Neal L. Hochwald G.Jeanette Thorbecke Gregory W. Siskind 《Cellular immunology》1984,85(1):25-33
Using hapten-reversible inhibition of plaque formation as an assay for auto-anti-idiotype antibody (anti-Id) and as a means for following idiotype (Id) expression, we have obtained evidence that following immunization with trinitrophenyl (TNP) conjugates (a) there are differences in Id expression in the anti-TNP antibody response to different TNP conjugates although there is some overlap; (b) different strains, although showing some differences in Id expression, tend to produce cross-reactive Ids, thus no obvious allotype linked inheritance of Id expression is observed in this heterogeneous immune response; (c) the auto-anti-Id produced following immunization with TNP-Brucella abortus or TNP-Ficoll tends to be of the IgG2a and IgG2b isotypes. 相似文献
8.
O Kuchel R Garcia W Debinski K Racz N T Buu M Cantin J Genest 《Proceedings of the Society for Experimental Biology and Medicine. Society for Experimental Biology and Medicine (New York, N.Y.)》1986,182(4):570-575
Conscious SHR and WKY rats were infused during 7 days with ANF (Arg 101-Tyr 126), 100 ng/hr/rat, by means of miniosmotic pumps and their basal blood pressure (BP), changes in sodium excretion and urinary catecholamines compared with those at the last day of the infusion. The SHR initial BP of 181 +/- 3 mmHg gradually declined to 137 +/- 5 mmHg. No significant change in blood pressure was observed in the ANF-infused WKY group. However, WKY rats exhibited an increased sodium excretion and urinary dopamine/norepinephrine ratio when compared to sham-infused rats. No such differences were observed in SHR. It is suggested that an ANF-induced withdrawal of the renal sympathetic tone permits the manifestation of its natriuretic action in WKY rats. When, however, a BP decrease predominates, as in SHR, this decrease results in a reflex sympathetic discharge with a renal sympathetic activity over-riding the ANF induced natriuresis seen in WKY rats. Secondary sympathetic responses to the ANF-induced BP decrease have to be thus taken into account when a dissociation between the hypotensive and natriuretic action of ANF is observed in vivo. 相似文献
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