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1.
The Escherichia coli dnaW mutation is an allele of the adk gene 总被引:3,自引:0,他引:3
Joan M. Henson Aleksandra Blinkowa James R. Walker 《Molecular & general genetics : MGG》1982,186(4):488-492
Summary A dnaW mutant, isolated on the basis of inability to effect conjugal DNA transfer at high temperature, has been shown by complementation and enzyme assay to be defective in the adk (adenylate kinase; EC 2.7.4.3) locus. The adk mutant, known to have reduced ATP concentration at the nonpermissive temperature (Cousin and Belaich 1966), was used to demonstrate a donor energy requirement for stable aggregate formation and for chromosome transfer in conjugation. 相似文献
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Lidija Simova Carolyn Williams Georgi D. Efremov Aleksandra Gordova-Muratovska Stojka Suštić Eila K. Watson Robert Williamson 《Human genetics》1990,85(4):432-433
Summary Chromosomes from 19 unrelated Southern Yugoslav families in which cystic fibrosis (CF) occurs were analysed for the presence
of the ΔF508 mutation, using polymerase chain reaction amplification followed by dot blot and polyacrylamide gel analysis.
Of the 38 CF chromosomes, 15 (39.5%) carry the ΔF508 deletion. Restriction fragment length polymorphism haplotypes for KM19/PstI, XV2c/TaqI and J3.11/PstI marker loci were determined and are compared for a total of 34 N and 37 CF chromosomes. 相似文献
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Lectins extracted from corn (Zea mays L.) kernel with Tris-HCl buffer pH 7.5 were isolated from the crude extract by affinity chromatography on Sepharose 6B-N-acetyl-d-galactosamine and Sepharose 6B-methylα-d-mannoside, and also by lectin affinity chromatography using concanavalin A and Lens culinaris lectin as ligands. According to preferential monosaccharide specificity, salt-soluble lectins of corn seed comprise at least two distinct types: N-acetyl-d-galactosamine-interactive and mannose-interactive lectins. The extracted lectins are unstable, with a tendency to form aggregates during storage. 相似文献
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The discharge pattern of cerebellar Purkinje cells and fastigial neurons was studied after acute amphetamine treatment in immobilized cats, as well as during generalized penicillin-induced epilepsy. There was a marked reversible decrease in spontaneous firing rate of Purkinje cells and an increase in spontaneous firing rate of fastigial neurons after acute d-1 amphetamine administration (5 mg/kg, s.c.). The discharge pattern of Purkinje cells showed tendency towards inhibition, while the fastigial neurons showed less clear tendency towards disinhibition in the course of epilepsy induced by parenteral administration of penicillin (400.000-500.000 I.U./kg, i.m.). Moreover, acute amphetamine treatment (5 mg/kg, s.c.) performed after the development of penicillin-induced epileptic episodes elicited a prominent suppression of Purkinje cell discharges associated with a parallel increase in discharges of fastigial neurons. These results suggest that the changes in discharge rate of cerebellar corticonuclear neurons induced by amphetamine contribute to suppression of seizural activity in the feline model of generalized epilepsy. 相似文献
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Milutin Miri Aleksandra Mikovi Sran Brki Jovan Vasiljevi Nenad Keserovi Milan Pei 《FEMS immunology and medical microbiology》1994,10(1):65-74
Abstract The randomized clinical trial with interferon-α (IFN) or thymic hormones versus conventional therapy was conducted in patients with myocarditis and idiopathic dilated cardiomyopathy (IDC). We enrolled 180 patients to receive IFN (3–5 million units per day) for 3 months, thymomodulin (10 mg three times per week) for 2 months, or conventional therapy alone. Patients were followed-up for 7 years after the end of treatment. Left ventricular function, exercise tolerance and survival rate were significantly better at long-term follow-up in patients treated with IFN or thymomodulin, than in conventionally treated patients. These results implicate that immune modulating therapy might represent important contribution in the treatment of myocarditis and IDC. 相似文献
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Aleksandra Marconi Cassandra Zie Yang Samuel McKay M. Emília Santos 《Evolution & development》2023,25(2):170-193
The cichlid fishes comprise the largest extant vertebrate family and are the quintessential example of rapid “explosive” adaptive radiations and phenotypic diversification. Despite low genetic divergence, East African cichlids harbor a spectacular intra- and interspecific morphological diversity, including the hyper-variable, neural crest (NC)-derived traits such as coloration and craniofacial skeleton. Although the genetic and developmental basis of these phenotypes has been investigated, understanding of when, and specifically how early, in ontogeny species-specific differences emerge, remains limited. Since adult traits often originate during embryonic development, the processes of embryogenesis could serve as a potential source of species-specific variation. Consequently, we designed a staging system by which we compare the features of embryogenesis between three Malawi cichlid species—Astatotilapia calliptera, Tropheops sp. ‘mauve’ and Rhamphochromis sp. “chilingali”—representing a wide spectrum of variation in pigmentation and craniofacial morphologies. Our results showed fundamental differences in multiple aspects of embryogenesis that could underlie interspecific divergence in adult adaptive traits. First, we identified variation in the somite number and signatures of temporal variation, or heterochrony, in the rates of somite formation. The heterochrony was also evident within and between species throughout ontogeny, up to the juvenile stages. Finally, the identified interspecific differences in the development of pigmentation and craniofacial cartilages, present at the earliest stages of their overt formation, provide compelling evidence that the species-specific trajectories begin divergence during early embryogenesis, potentially during somitogenesis and NC development. Altogether, our results expand our understanding of fundamental cichlid biology and provide new insights into the developmental origins of vertebrate morphological diversity. 相似文献
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