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11.
12.
Cell type-specific expression of the human renin gene. 总被引:2,自引:0,他引:2
A Fukamizu S Uehara K Sugimura Y Kon M Sugimura T Hasegawa M Yokoyama T Nomura M Katsuki K Murakami 《Journal of biological regulators and homeostatic agents》1991,5(3):112-116
We have previously produced transgenic mice carrying the human renin gene, whose expression is regulated in a tissue-specific manner. In the present study, we further characterized expression of the transgene. Northern blot analysis showed that the human renin gene is expressed in the kidney but not in the liver of two lines of transgenic mice with 10 and 50 copies of the transgene, suggesting that the integrated copy number of the human renin gene does not influence the dominant-renal expression pattern. Immunohistochemical study using a monoclonal antibody specific for human renin demonstrated that expression of human renin in the transgenic mouse kidney is confined to the epithelioid juxtaglomerular cells. Transfection experiments indicated that the chloramphenicol acetyltransferase fusion gene containing the 3-kb upstream sequences of the renin gene is activated only in human epithelioid embryonic 293 cells derived from kidney but not in human HepG2 cells from liver. These findings suggest that transfer of the cloned renin gene into mice and in vitro cultured cell lines can give rise to cell type-specific expression. 相似文献
13.
J. Koníček M. Koníčková-Radochová G. Y. Daraselia M. Šlosárek 《Folia microbiologica》1988,33(1):71-79
It is generally assumed that genetic research of mycobacteria is delayed as compared with other, more commonly used, bacterial models, particularly in the field of genetic transfers. In the field of mutagenesis the problems have been studied to such an extent that replication maps of the chromosome of M. phlei and M. tuberculosis H37 Rv have already been constructed and a new model of the cell cycle of bacteria exhibiting a slow growth rate has been worked out. When the problems of mycobacterial genetics are looked upon in the light of gene manipulations it may be concluded that mycobacteria belong to a few models whose genes are used for cloning and that problems of practical significance will be studied by means of the most modern approaches. 相似文献
14.
L Y Lian 《Biochemical and biophysical research communications》1988,154(3):1253-1259
In our attempts to obtain total sequential assignment of the 1H NMR spectrum of ribonuclease A, several published water suppression techniques were tested and assessed. The jump- and-return sequence and its echo hybrid were used with considerable success in both the TOCSY and NOESY experiments on 3mM ribonuclease A solutions. The NMR approach used here may be of general applicability for 1H NMR studies of proteins in water of concentrations under 5mM. 相似文献
15.
The association between paternal age and the occurrence of birth defects was studied using data collected in Metropolitan Atlanta. Paternal-age information for babies born with defects was obtained from birth certificates, hospital records, and interviews with mothers; for babies born without defects, the information was obtained from birth certificates. Several statistical techniques were used to evaluate the paternal-age-birth-defects associations for 86 groups of defects. Logistic regression analysis that controlled for maternal age and race indicated that older fathers had a somewhat higher risk for having babies with defects, when all types of defects were combined; an equivalent association for older mothers was not found. Logistic regression analyses also indicated modestly higher risks for older fathers for having babies with ventricular septal defects and atrial septal defects and substantially higher risks for having babies with defects classified in the category chondrodystrophy (largely sporadic achondroplasia) and babies with situs inversus. An association between elevated paternal age and situs inversus has not been reported before; the magnitude of the estimated increased risk for situs inversus was about the same as that found in this study for chondrodystrophy. 相似文献
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Formation of protoplasts and their reversion were followed in 7 strains of brevibacteria. The formation of protoplasts and
their reversion differed both between various species of brevibacteria and between various mutant strains of the same species. 相似文献
19.
Ribonuclease A: carbon-13 nuclear magnetic resonance assignments, binding sites, and conformational flexibility 总被引:2,自引:0,他引:2
Assignments have been made for 11 methyl, one Gln-C gamma, one Thr-C beta, and all six Tyr-C zeta carbon resonances of ribonuclease A. These partially serve to delineate the binding sites for Cu2+, Mn2+, phosphate, cytidine and its 2'-, 3'-, and 5'-phosphates (Cyd and Cyd-2'-P, -3'-P, and -5'-P), and one or a few urea molecules at low concentration. Evidence is presented for a conformational change, and hence flexibility, in the active site region around the optimum pD for enzymic activity and another such change at around the optimum temperature. The binding of cytidine-containing ligands is shown to have extensive conformational consequences for methyl groups but less for hydrophobic aromatic residues, implying that the former make a special contribution to molecular flexibility. The cytosine ring in Cyd-2'-P, -3'-P, and -5'-P is found to be close but far from parallel to the ring of Phe-120. In contrast to previous claims, ribonuclease A is shown not to unfold even partially before denaturation. On denaturation, it passes to a new but structured state. 相似文献
20.
Mating behaviour ofTokunagayusurika akamusi searching at the resting place (lakeside vegetation, although mating also occurs in the air by swarming) was investigated
at the shore of Lake Biwa. Coinciding with the arrival of newly emerged adults, previously emerged males walked about to search
for mates at the resting place. When a searching male came into contact with a fresh (newly emerged) individual, he attempted
to copulate with it regardless of its sex. Consequently, males copulated with fresh females, which were more likely to be
virgin at the resting place, suggesting that the first male might contribute best to the fertilization. 相似文献