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541.
542.
A. W. A. M. de Cock 《Antonie van Leeuwenhoek》1994,65(1):21-28
Fifteen isolates ofHortaea werneckii, causative agent of tinea nigra in man, were examined with respect to restriction fragment length polymorphisms of mitochondrial DNA. Seven types of mtDNA, interpreted as populations, could be distinguished, with similarities between the restriction patterns ranging from 32 to 79%. Much of the variance originated from length mutations. Of the seven populations four represented isolates from man, two of which also comprised isolates from other sources. This makes adaptation ofH. werneckii towards association with man in its evolution unlikely; similarity in the chemical and/or physical characteristics of the different isolation sources, viz. salinity, seems more probable. mtDNA types were not correlated with geographic origin. Isolates with the same mtDNA type are widely geographically distributed. 相似文献
543.
To determine relatedness of the phytopathogenic fungi Phytophthora infestans , P. mirabilis , and P. phaseoli restriction fragment patterns of mitochondrial DNAs of several isolates and hybridization patterns of nuclear DNAs after Southern hybridization with a specific homologous probe were analyzed.
All but two isolates of P. infestans and P. mirabilis show very similar restriction fragment patterns differing only in the length of one fragment due to small insertion/deletion(s). Two isolates of P. mirabilis have one additional site for Scr FI. On the contrary at least six sites differ in P. phaseoli when compared to the other two species. The mitochondrial genome of P. phaseoli is considerably smaller (approx. 6 kbp) than those of P. infestans and P. mirabilis .
A cloned 430 bp multicopy DNA sequence, derived from P. infestans , hybridized specifically with P. infestans, P. mirabilis , and P. phaseoli out of 61 species of Peronosporales ( Phytophthora, Halophytophthora, Pythium, Albugo, Bremia, Peronospora, Plasmopara ) tested and therefore has potential as a diagnostic probe. Restriction patterns revealed by this probe are invariant intraspecifi-cally but differ between the three species.
We consider P. mirabilis a forma specialis of P. infestans because of the very high similarly in its mitochondrial DNA restriction patterns. 相似文献
All but two isolates of P. infestans and P. mirabilis show very similar restriction fragment patterns differing only in the length of one fragment due to small insertion/deletion(s). Two isolates of P. mirabilis have one additional site for Scr FI. On the contrary at least six sites differ in P. phaseoli when compared to the other two species. The mitochondrial genome of P. phaseoli is considerably smaller (approx. 6 kbp) than those of P. infestans and P. mirabilis .
A cloned 430 bp multicopy DNA sequence, derived from P. infestans , hybridized specifically with P. infestans, P. mirabilis , and P. phaseoli out of 61 species of Peronosporales ( Phytophthora, Halophytophthora, Pythium, Albugo, Bremia, Peronospora, Plasmopara ) tested and therefore has potential as a diagnostic probe. Restriction patterns revealed by this probe are invariant intraspecifi-cally but differ between the three species.
We consider P. mirabilis a forma specialis of P. infestans because of the very high similarly in its mitochondrial DNA restriction patterns. 相似文献
544.
F M Clarke C Orozco A V Perkins I Cock K F Tonissen A J Robins J R Wells 《Journal of reproduction and fertility》1991,93(2):525-539
An isolated preparation from ovine placental extracts which was active in the rosette inhibition assay mimicking the activity of the so-called 'early pregnancy factor' (EPF) has been shown to contain a 12 kDa polypeptide which could be partially resolved from low-molecular-weight active moieties. N-terminal amino acid sequence analysis of the polypeptide indicated that it was ovine thioredoxin, an identification confirmed by isolation and complete sequence analysis of the corresponding cDNA. The cDNA for human thioredoxin was expressed in Escherichia coli and the recombinant protein isolated and purified. Pure recombinant thioredoxin alone did not induce the expression of increased rosette inhibition titres (RITs) when tested in the rosette inhibition assay; but, when tested in combination with cell stimuli such as platelet-activating factor (PAF) or serum, it allowed the expression of increased RITs where none was achieved in its absence. Thioredoxin acted in the assay to reverse a refractory state normally induced by these stimuli, allowing lipoxygenase-dependent moieties also induced by the stimuli to exert their effects, resulting in the expression of increased RITs. Antibodies to recombinant thioredoxin removed from pregnancy sera the capacity to induce increased RITs, i.e. to express EPF activity, thus establishing a role for thioredoxin or thioredoxin-like proteins and associated molecules in the mechanisms which allow pregnancy sera to induce increased RITs. Based on a consideration of these and other results, a new model for the study of the EPF phenomenon is presented and discussed. 相似文献