Tepidimonas aquatica sp. nov., a new slightly thermophilic beta-proteobacterium isolated from a hot water tank

A bacterial isolate, with an optimum growth temperature of about 50 degrees C, was recovered from a domestic hot water tank in Coimbra. Phylogenetic analysis using 16S rRNA gene sequence indicated that strain CLN-1T is a member of the beta-Proteobacteria and represents a new species of the genus Tepidimonas. The major fatty acids of strain CLN-1T are 16:0, 17:0 cyclo and 16:1 omega7c. Ubiquinone 8 is the major respiratory quinone, the major polar lipids are phosphatidylethanolamine, and phosphatidylglycerol. The new isolate is aerobic and facultatively chemolithoheterotrophic. Thiosulfate and tetrathionate are oxidized to sulfate in the presence of a metabolizable carbon source. Strain CLN-1T grows on amino acids and organic acids, but this organism does not assimilate carbohydrates. Glycerol is the only polyol assimilated. Resinic acids, namely abietic acid, dehydroabietic acid and isopimaric acid are not degraded. On the basis of the phylogenetic analyses, physiological and biochemical characteristics, we propose that strain CLN-1T represents a new species for which we offer the name Tepidimonas aquatica.     

Effects of black-eyed pea trypsin/chymotrypsin inhibitor on proteolytic activity and on development of Anthonomus grandis

The cotton boll weevil Anthonomus grandis (Boheman) is one of the major pests of cotton (Gossypium hirsutum L.) in tropical and sub-tropical areas of the New World. This feeds on cotton floral fruits and buds causing severe crop losses. Digestion in the boll weevil is facilitated by high levels of serine proteinases, which are responsible for the almost all proteolytic activity. Aiming to reduce the proteolytic activity, the inhibitory effects of black-eyed pea trypsin/chymotrypsin inhibitor (BTCI), towards trypsin and chymotrypsin from bovine pancreas and from midguts of A. grandis larvae and adult insects were analyzed. BTCI, purified from Vigna unguiculata (L.) seeds, was highly active against different trypsin-like proteinases studied and moderately active against the digestive chymotrypsin of adult insects. Nevertheless, no inhibitory activity was observed against chymotrypsin from A. grandis larval guts. To test the BTCI efficiency in vivo, neonate larvae were reared on artificial diet containing BTCI at 10, 50 and 100 microM. A reduction of larval weight of up to approximately 54% at the highest BTCI concentration was observed. At this concentration, the insect mortality was 65%. This work constitutes the first observation of a Bowman-Birk type inhibitor active in vitro and in vivo toward the cotton boll weevil A. grandis. The results of bioassays strongly suggest that BTCI may have potential as a transgene protein for use in engineered crop plants modified for heightened resistance to the cotton boll weevil.     

Isoenzymatic variability among five Anopheles species belonging to the Nyssorhynchus and Anopheles subgenera of the Amazon region,Brazil

An isoenzymatic comparative analysis of the variability and genetics differentiation among Anopheles species was done in populations of An. (Nys.) intermedius and An. (Ano.) mattogrossensis of the Anopheles subgenus, and of An. darlingi, An. albitarsis and An. triannulatus of the Nyssorhynchus subgenus, with the aim of detecting differences between both subgenera and of estimating the degree of genetic intere specific divergence. Samples from Macap , State of Amap and Janauari Lake, near Manaus, State of Amazonas, were analyzed for eight isoenzymatic loci. Analysis revealed differences in the average number of alleles per locus (1.6-2.3) and heterozygosity (0.060-0.284). However, the proportion of polymorphic loci was the same for An. (Nys.) darlingi, An. (Nys.) triannulatus and An. (Ano.) mattogrossensis (50%), but differed for An. (Nys.) albitarsis (62.5%) and An. (Ano.) intermedius (25%). Only the IDH1 (P > 0.5) locus in all species studied was in Hardy-Weinberg equilibrium. The fixation index demonstrated elevated genetic structuring among species, based on values of Fst = 0.644 and genetic distance (0.344-0.989). Genetic difference was higher between An. (Nys.) triannulatus and An. (Ano.) intermedius (0.989) and smaller between An. (Nys.) albitarsis sensu lato and An. (Nys.) darlingi (0.344). The data show interspecific genetic divergence which differs from the phylogenetic hypothesis based on morphological characters.     

Molecular model of cyclin-dependent kinase 5 complexed with roscovitine

Here is described a structural model for the binary complex CDK5-roscovitine. Roscovitine has been shown to potently inhibit cyclin-dependent kinases 1, 2 and 5 (CDK1, 2, and 5), and the structure of CDK2 complexed with roscovitine has been reported; however, no structural data are available for complexes of CDK5 with inhibitors. The structural model indicates that roscovitine strongly binds to the ATP-binding pocket of CDK5 and structural comparison of the CDK2-roscovitine complex correlates the structural differences with differences in inhibition of these CDKs by this inhibitor. This structure opens the possibility of testing new inhibitor families, in addition to new substituents for the already known lead structures of adenine derivatives.     

Observations on mouthparts of Dermatobia hominis (Linneaus Jr., 1781) (Diptera: Cuterebridae) by scanning electron microscopy

The ultrastructure of the mouthparts of Dermatobia hominis was studied using scanning electron microscopy. The morphological characteristics of the segments, articulations, sensory organs, and pilose covering are described. Mechanoreceptors of the long trichoid sensillum and smaller trichoid sensillum types were observed, as well as labellar gustatory receptors of the basiconic sensillum type, which differed between the sexes. These observations are discussed with reference to the current literature on the morphology and sense organs of dipteran mouthparts, and the prevailing view that the adult mouthparts of this species are non-functional is challenged.     

Butterfly Communities of Urban Forest Fragments in Campinas, São Paulo, Brazil: Structure, Instability, Environmental Correlates, and Conservation

A comparative study of butterfly communities in 15 urban/suburban remnants of tropical semideciduous forest in Campinas (São Paulo state, SE Brazil; 24°S, 47°W), with areas from 1.0 to 252ha and widely varying histories and environments, shows that the most significant factors, besides area and sampling time, distinguishing the sites and influencing their diversity (80–702 species) and composition are connectivity, permanent water, vegetation, flowers, and human impact (negative, including pollution). The diversified Nymphalidae butterflies (38–213 species) and especially two fermented-bait-attracted groups (Satyrinae, 2–30 species, and Biblidini, 9–44 species), are among the more useful indicators of the quality and diversity of the environments in these fragments. Effective conservation of butterfly communities in tropical cities may be achieved by maintenance of arboreal green corridors along streets and watercourses between moderately large (>10ha) humid areas, not near to the most built-up or polluted city centre(s), and the inclusion within these areas of ponds or streams, diversified native forest, and open vegetation including abundant nectar-rich flowers.     

Repair of amino acid radicals of apolipoprotein B100 of low-density lipoproteins by flavonoids. A pulse radiolysis study with quercetin and rutin

Selective oxidative damage to apolipoprotein B in LDL can be effected radiolytically by (*)Br(2)(-) radicals. Twenty-seven Trp residues constitute major primary sites of oxidation, but two-thirds of oxidized Trps ((*)Trp) that are formed are repaired by intramolecular electron transfer from Tyr residues with formation of phenoxyl radicals (TyrO(*)). Analysis of (*)Trp and TyrO(*) transient absorbance changes suggests that other apolipoprotein B residues, probably Cys, are oxidized. LDL-bound quercetin can efficiently repair this damage. Absorption studies show that a LDL particle has the capacity to bind approximately 10 quercetin molecules through interaction with apolipoprotein B. The repair occurs by intramolecular electron transfer characterized by a rate constant of 2 x 10(3) s(-)(1). In contrast, rutin, a related flavonoid which does not bind to LDL, cannot repair oxidized apolipoprotein B. Urate is a hydrophilic plasma antioxidant which displays synergistic antioxidant properties with flavonoids. Urate radicals produced by (*)Br(2)(-) can also be repaired by LDL-bound quercetin. This repair occurs with a reaction rate constant of 6.8 x 10(7) M(-)(1) s(-)(1). Comparison with previous studies conducted with human serum albumin-bound quercetin suggests that quercetin analogues tailored to be carried preferentially by lipoproteins might be more powerful plasma antioxidants than natural quercetin carried by serum albumin.     

Update of microbial genome programs for bacteria and archaea

Since the Haemophilus influenzae genome sequence was completed in 1995, 172 other prokaryotic genomes have been completely sequenced, while 508 projects are underway. Besides pathogens, organisms important in several other fields, such as biotechnology and bioremediation, have also been sequenced. Institutions choose the organisms they wish to sequence according to the importance that these species represent to them, the availability of the microbes, and based on the similarity of a species of interest with others that have been sequenced previously. Improvements in sequencing techniques and in associated methodologies have been achieved; however, scientists need to continue working on the development of this field. In Brazil, a multicentered, centrally coordinated and research-focused network was adopted and successfully used for the sequencing of several important organisms. We analyzed the current status of microbial genomes, the trends for criteria used to choose new sequencing projects, the future of microbial sequencing, and the Brazilian genome network.     

Spared bone mass in rats treated with thyroid hormone receptor TR beta-selective compound GC-1

Thyrotoxicosis is frequently associated with increased bone turnover and decreased bone mass. To investigate the role of thyroid hormone receptor-beta (TR beta) in mediating the osteopenic effects of triiodothyronine (T3), female adult rats were treated daily (64 days) with GC-1 (1.5 microg/100 g body wt), a TR beta-selective thyromimetic compound. Bone mass was studied by dual-energy X-ray absorptiometry of several skeletal sites and histomorphometry of distal femur, and the results were compared with T3-treated (3 microg/100 g body wt) or control animals. As expected, treatment with T3 significantly reduced bone mineral density (BMD) in the lumbar vertebrae (L2-L5), femur, and tibia by 10-15%. In contrast, GC-1 treatment did not affect the BMD in any of the skeletal sites studied. The efficacy of GC-1 treatment was verified by a reduction in serum TSH (-52% vs. control, P < 0.05) and cholesterol (-21% vs. control, P < 0.05). The histomorphometric analysis of the distal femur indicated that T3 but not GC-1 treatment reduced the trabecular volume, thickness, and number. We conclude that chronic, selective activation of the TR beta isoform does not result in bone loss typical of T3-induced thyrotoxicosis, suggesting that the TR beta isoform is not critical in this process. In addition, our findings suggest that the development of TR-selective T3 analogs that spare bone mass represents a significant improvement toward long-term TSH-suppressive therapy.