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21.

Background  

Phylogenetic analysis of human complete mitochondrial DNA sequences has largely contributed to resolving phylogenies and antiquity of different lineages belonging to the majorhaplogroups L, N and M (East-Asian lineages). In the absence of whole mtDNA sequence information of M lineages reported in India that exhibits highest diversity within the sub-continent, the present study was undertaken to provide a detailed analysis of this haplogroup to precisely characterize the lineages and unravel their intricate phylogeny.  相似文献   
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Changes in respiratory activity and in the contents of adenine nucleotides (ATP, ADP, AMP) were studied in cells of the yeast Yarrowia lipolytica during the development of cyanide-resistant respiration. The transition of the yeast from the logarithmic to the stationary growth phase due to exhaustion of glucose was associated with decreased endogenous respiration and with the activation of a cyanide-resistant oxidase. Cyanide activated cell respiration during the stationary growth phase. The cyanide-resistant respiration was inhibited by benzohydroxamic acid (BHA), an inhibitor of the alternative oxidase. In the absence of cyanide, BHA had no effect on the cells which had the cyanide-resistant oxidase. This indicates that the cells do not use the alternative pathway in vivo. The decreased endogenous respiration of the cells was accompanied by decreased contents of adenine nucleotides. Addition of cyanide resulted in a sharp decrease in the content of ATP, in a twofold increase in the content of ADP, and in a fivefold increase in the content of AMP. In the absence of cyanide, BHA had virtually no effect on the contents of adenine nucleotides. The decreased rate of oxygen consumption during the transition of the cells to the stationary growth phase was caused by the decreased activity of the main cytochrome-containing respiratory chain (2,4-dinitrophenol (DNP) stimulated respiration). The alternative oxidase was synthesized in the cell but was inactive. Cyanide stimulated respiration due to activation of the alternative oxidase via the AMP produced. The decrease in the cell content of ATP is suggested to be a factor inducing the synthesis of the alternative oxidase.  相似文献   
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Applied Biochemistry and Microbiology - We studied the biosynthesis of colored naphthoquinone metabolites by Fusarium decemcellulare, F. graminearum, and F. bulbigenum fungi. Depending on the...  相似文献   
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A 25-year-old previously asymptomatic pregnant woman at 36 weeks'' gestation was noticed to have repetitive monomorphic ventricular tachycardia. A dilated left ventricle with moderately reduced systolic function was found on echocardiographic examination. This is a very rare presentation of peripartum cardiomyopathy (PPCMP) presenting with repetitive monomorphic ventricular tachycardia.  相似文献   
26.
In this paper we study the nonlinear age-structured model of a polycyclic two-phase population dynamics including delayed effect of population density growth on the mortality. Both phases are modelled as a system of initial boundary values problem for semi-linear transport equation with delay and initial problem for nonlinear delay ODE. The obtained system is studied both theoretically and numerically. Three different regimes of population dynamics for asymptotically stable states of autonomous systems are obtained in numerical experiments for the different initial values of population density. The quasi-periodical travelling wave solutions are studied numerically for the autonomous system with the different values of time delays and for the system with oscillating death rate and birth modulus. In both cases it is observed three types of travelling wave solutions: harmonic oscillations, pulse sequence and single pulse.  相似文献   
27.
The phenomenon of cyanide-resistant respiration was studied in bacteria as well as its relation to the oversynthesis of metabolites. Cyanide-resistant respiration was shown to be common of aerobic and facultative anaerobic bacteria. The resistance of respiration to cyanide was observed when the growth of a microbial culture was inhibited or ceased entirely, provided the culture lacked the oversynthesis of metabolites. When a culture was capable of metabolites oversynthesis under such conditions, cyanide-resistant respiration (if any) declined. Therefore, there is a competition between metabolites oversynthesis and cyanide-resistant respiration, which is typical of many microorganisms.  相似文献   
28.
Sawdust, a bulky waste generated by wood processing industries, has very few profitable and ecofriendly uses and poses a problem of proper disposal. Treatment with the fungusVolvariella volvaceae and a dilute solution of urea converted sawdust from a phytoinhibitory material to a phytostimulatory soil conditioner. In different types of soils, the soil conditioner increased the moisture retention and facilitated the cohesive interaction of particles. Analyses of the major biopolymers of sawdust after fungal treatment indicated that levels of cellulose, hemicellulose and lignin decreased; however, these changes did not account for the plant growth stimulatory property attained by this material.  相似文献   
29.
The zebrafish genome contains at least five msx homeobox genes, msxA, msxB, msxC, msxD, and the newly isolated msxE. Although these genes share structural features common to all Msx genes, phylogenetic analyses of protein sequences indicate that the msx genes from zebrafish are not orthologous to the Msx1 and Msx2 genes of mammals, birds, and amphibians. The zebrafish msxB and msxC are more closely related to each other and to the mouse Msx3. Similarly, although the combinatorial expression of the zebrafish msx genes in the embryonic dorsal neuroectoderm, visceral arches, fins, and sensory organs suggests functional similarities with the Msx genes of other vertebrates, differences in the expression patterns preclude precise assignment of orthological relationships. Distinct duplication events may have given rise to the msx genes of modern fish and other vertebrate lineages whereas many aspects of msx gene functions during embryonic development have been preserved.   相似文献   
30.
Enhancer activity of the rabbit immunoglobulin kappa light chain gene intron conserved region (KICR) was examined in mouse myeloma cells using transient expression experiments. Compared to the homologous region of the mouse kappa light chain gene, the rabbit KICR shows nearly no stimulatory effect on expression of the indicator gene, cat. Experiments with mouse-rabbit chimeric KICRs indicated that differences in the region around the NF-kappa B binding site are responsible for the impaired activity of the rabbit KICR whereas mouse sequences covering the kappa E2 and kappa E3 motifs can be replaced by the equivalent rabbit fragment without affecting enhancer function. Creation of a perfect mouse NF-kappa B target sequence in the rabbit gene only partially restores enhancer activity. Furthermore, mouse and rabbit DNA fragments encompassing the NF-kappa B target sequence behave in an identical manner in an electrophoretic mobility shift assay. The results indicate species-related functional differences in the immunoglobulin kappa light chain gene enhancer and suggest that although the NF-kappa B binding site plays a crucial role in enhancer activity surrounding gene elements are also necessary for full enhancer effect.  相似文献   
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