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We have observed (AT)34 and (AT)23 tracts close to the coding sequences of the Xenopus laevis tadpole alpha T1 and adult beta 1 globin genes, respectively. We show that (AT)n sequences are found as interspersed repeats within the Xenopus globin and histone gene loci. Using (AT)n co-polymer in filter hybridisation experiments we estimate that there are 10(4) (AT)n tracts per haploid Xenopus genome. Hybridisation to genomic blots of DNA from yeast, slime mold, trypanosome, fruit fly, salmon, chicken, rat, human, crab and Xenopus species shows that strictly alternating AT of sufficient length to hybridise appears to be most abundant in Xenopus and crab genomes. We show that the specificity of the co-polymer probe for strictly alternating AT is, however, dependent on the length of the probe. Hybridisation experiments using (TG)n copolymer suggest that this highly conserved repeat is found as clustered repeats in the Xenopus genome in contrast to other eukaryotic genomes so far studied. 相似文献
3.
J. Fábregas E. D. Morales N. Polanco M. Patiño A. Otero J. F. Tobar 《World journal of microbiology & biotechnology》1996,12(1):47-49
The marine microalga Phaeodactylum tricornutum was cultivated in semi-continuous culture under mixotrophic conditions with the soluble fractions of potato, rye and wheat flours that had been naturally fermented, at 2% or 4% (w/v). The rye flour produced the highest microalgal cellular density of 90×106 cells.ml-1 when supplemented with NaNO3 and NaH2PO4. The autotrophic control only gave 57×106 cells.ml-1. The value of agricultural surpluses, such as rye flour, can therefore be increased by its use in the production of valuable, microalgal biomass which is rich in protein, pigments and fatty acids. 相似文献
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In the third week of September 1989, birds were purchased locally and acclimated to their housing conditions in a room fully exposed to natural day length (average: 11.96 hr) and temperature (26 degrees +/- 2 degrees C) for 2 weeks. Birds were in the regressive phase of their annual gonadal cycle. In the first experiment 24 birds were selected randomly and were divided into 3 groups of 8 birds each. Initial body weight and bill color score were recorded. The birds of group-I and group-II were injected daily with 5 and 10 micrograms of melatonin in 0.1 ml of vehicle, respectively. The birds of group-III were injected with vehicle only and treated as control. Injections were given daily between 1700 and 1730 hrs over a period of 10 days. At the termination of the experiment, the birds were weighed, sacrificed, bill color scored, blood collected and immediately processed to determine the number of erythrocytes and hemoglobin concentration. The mean body weight loss amounted to 9.6% in vehicle-treated house sparrow. Birds receiving low and high doses of melatonin maintained their initial body weight. Melatonin significantly accelerated the rate of bleaching of bill color. Results clearly indicate that in house sparrow, melatonin produces prosomatotrophic and antigonadotrophic effects. The low dose of melatonin stimulated erythropoiesis significantly. In the second experiment, melatonin nullified the castration-induced decline in the number of circulating red cells. This clearly suggests that the influence of melatonin on erythropoietic machinery appears to be independent of testicular hormone(s). 相似文献
6.
B. Akbar John B. R. Nelson Hassan I. Sheikh S. G. Cheung Yusli Wardiatno Bisnu Prasad Dash Keiji Tsuchiya Yumiko Iwasaki Siddhartha Pati 《Biodiversity and Conservation》2018,27(14):3573-3598
Horseshoe crabs are the only extant xiphosurans and are believed to be morphologically unchanged for more than 200 million years. Of the four extant species namely, Limulus polyphemus, Tachypleus tridentatus, Tapinauchenius gigas and Carcinoscorpius rotundicauda, the latter three are found in Asian waters. Recent evidences showed that Asian horseshoe crabs are facing serious threats such as degradation of their spawning grounds and habitat, environmental pollution, overexploitation as a culinary delicacy and biomedical bleeding practices. Baseline data on the distribution and existing population of the wild horseshoe crabs remain poorly known in several Asian regions. Several studies have clearly revealed that pressure due to over-fishing of wild stock has increased tremendously in the last decade. Due to an increase in demand for Tachypleus Amebocyte Lysate (TAL) analogous to Limulus Amebocyte Lysate (LAL) in the United States, there is an urgent need to comprehensively address their fishing and conservation measures in the Asian region. This review addresses the overall studies on three species of Asian horseshoe crabs in relation to their fishing practices, local exploitation of their wild stock either for human consumption (or) by biomedical industries. The authors have structured the discussion on an international scale to address the existing problems in fishing and conservation of horseshoe crabs. Since no specific regulatory force or legislative protection act or a policy to preserve their natural stock are available to this date, this paper strongly recommends representative countries to include horseshoe crabs under their wildlife protection act to avoid further unsustainable exploitation of their wild populations. 相似文献
7.
Nisha Saxena Nimisha Singh Mridul Mishra G. B. Shiva Keshava Praveen Kumar Shukla Rama Pati Tripathi 《Journal of enzyme inhibition and medicinal chemistry》2013,28(4):476-482
A series of azatricyclodiones and octahydro-benzo[f]isoindoles have been synthesized by (4+2) Diels-Alder cycloaddition of maleimides with furfuryl amine. Reaction of azatricyclodiones with isocyanates led to the respective ureides. All of the compounds were screened against a number of bacteria and fungi. One of the compounds (2) displayed moderate antitubercular activity while two compounds (2) and (4) inhibited the fungal growth at 25 μg/mL. 相似文献
8.
Synthesis and biological evaluation of potential modulators of malarial glutathione-S-transferase(s)
Rumana Ahmad Arvind K. Srivastava Rama Pati Tripathi Sanjay Batra Rolf D. Walter 《Journal of enzyme inhibition and medicinal chemistry》2013,28(3):327-342
Glutathione-S-transferase(s) (E.C.2.5.1.18, GSTs) have been investigated in parasitic protozoans with respect to their biochemistry and they have been identified as potential vaccine candidates in protozoan parasites and as a target in the synthesis of new antiparasitic agents. In a search towards the identification of novel biochemical targets for antimalarial drug design, the area of Plasmodium glutathione metabolism provides a number of promising chemotherapeutic targets. GST activity was determined in various subcellular fractions of malarial parasites Plasmodium yoelii and was found to be localized mainly in the cytosolic fraction (specific activity, c. 0.058 ± 0.016 μmol/min/mg protein). Hemin, a known inhibitor of mammalian GST(s), maximally inhibited this enzyme from P. yoelii to nearly 86%. In a search towards synthetic modulators of malarial GST(s), 575 compounds belonging to various chemical classes were screened for their effect on crude GST from P. yoelii and 92 compounds belonging to various chemical classes were studied on recombinant GST from P. falciparum. Among all the compounds screened, 83 compounds inhibited/stimulated the enzyme from P. yoelii/P. falciparum to the extent of 40% or more. 相似文献
9.
Fabrice E. Graf Philipp Ludin Tanja Wenzler Marcel Kaiser Reto Brun Patient Pati Pyana Philippe Büscher Harry P. de Koning David Horn Pascal M?ser 《PLoS neglected tropical diseases》2013,7(10)
The predominant mechanism of drug resistance in African trypanosomes is decreased drug uptake due to loss-of-function mutations in the genes for the transporters that mediate drug import. The role of transporters as determinants of drug susceptibility is well documented from laboratory-selected Trypanosoma brucei mutants. But clinical isolates, especially of T. b. gambiense, are less amenable to experimental investigation since they do not readily grow in culture without prior adaptation. Here we analyze a selected panel of 16 T. brucei ssp. field isolates that (i) have been adapted to axenic in vitro cultivation and (ii) mostly stem from treatment-refractory cases. For each isolate, we quantify the sensitivity to melarsoprol, pentamidine, and diminazene, and sequence the genomic loci of the transporter genes TbAT1 and TbAQP2. The former encodes the well-characterized aminopurine permease P2 which transports several trypanocides including melarsoprol, pentamidine, and diminazene. We find that diminazene-resistant field isolates of T. b. brucei and T. b. rhodesiense carry the same set of point mutations in TbAT1 that was previously described from lab mutants. Aquaglyceroporin 2 has only recently been identified as a second transporter involved in melarsoprol/pentamidine cross-resistance. Here we describe two different kinds of TbAQP2 mutations found in T. b. gambiense field isolates: simple loss of TbAQP2, or loss of wild-type TbAQP2 allele combined with the formation of a novel type of TbAQP2/3 chimera. The identified mutant T. b. gambiense are 40- to 50-fold less sensitive to pentamidine and 3- to 5-times less sensitive to melarsoprol than the reference isolates. We thus demonstrate for the first time that rearrangements of the TbAQP2/TbAQP3 locus accompanied by TbAQP2 gene loss also occur in the field, and that the T. b. gambiense carrying such mutations correlate with a significantly reduced susceptibility to pentamidine and melarsoprol. 相似文献
10.
Wayne Reeve Rui Tian Sofie De Meyer Vanessa Melino Jason Terpolilli Julie Ardley Ravi Tiwari John Howieson Ronald Yates Graham O’Hara Mohamed Ninawi Hazuki Teshima David Bruce Chris Detter Roxanne Tapia Cliff Han Chia-Lin Wei Marcel Huntemann James Han I-Min Chen Konstantinos Mavromatis Victor Markowitz Natalia Ivanova Galina Ovchinnikova Ioanna Pagani Amrita Pati Lynne Goodwin Sam Pitluck Tanja Woyke Nikos Kyrpides 《Standards in genomic sciences》2013,9(2):243-253
Rhizobium leguminosarum bv. trifolii strain TA1 is an aerobic, motile, Gram-negative, non-spore-forming rod that is an effective nitrogen fixing microsymbiont on the perennial clovers originating from Europe and the Mediterranean basin. TA1 however is ineffective with many annual and perennial clovers originating from Africa and America. Here we describe the features of R. leguminosarum bv. trifolii strain TA1, together with genome sequence information and annotation. The 8,618,824 bp high-quality-draft genome is arranged in a 6 scaffold of 32 contigs, contains 8,493 protein-coding genes and 83 RNA-only encoding genes, and is one of 20 rhizobial genomes sequenced as part of the DOE Joint Genome Institute 2010 Community Sequencing Program. 相似文献