The Influence of Nutrigenetics on the Lipid Profile: Interaction Between Genes and Dietary Habits

Nutrigenetics is a new field with few studies in Latin America. Our aim is to investigate the way in which different genes related to the lipid profile influence the response to specific dietary habits. Eight polymorphisms on seven genes were investigated in a sample (n = 567) from Porto Alegre, RS, Brazil. All the volunteers completed a food diary that was then assessed and classified into nine food groups. A number of nutrigenetic interactions were detected primarily related to the apolipoprotein E (apoE) gene. For example, frequent consumption of foods rich in polyunsaturated fat resulted in the beneficial effect of increasing HDL-C only in individuals who were not carriers of the E*4 allele of the APOE gene, whereas variations in eating habits of E*4 carriers did not affect their HDL-C (P = 0.018). Our data demonstrate for the first time nutrigenetic interactions in a Brazilian population.     

Brongniartia papyracea (Fabaceae: Faboideae): A new species from the tropical deciduous forest of southern Jalisco and southwestern Michoacán, Mexico

A new species,Brongniartia papyracea (Fabaceae: Faboideae), from southern Jalisco and southwestern Michoacán, is described and illustrated. Its morphological affinities withB. podalyrioides from central Mexico are discussed, and habitat data are given.

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Résumé  Se describe una especie nueva,Brongniartia papyracea (Fabaceae: Faboideae), del sur de Jalisco y suroeste de Michoacán, México. Se discuten sus afinidades morfológicas conB. podalyrioides des centro de México y se proporcionan datos de su hábitat.

     

The peptide-binding and ATPase domains of recombinant hsc70 are required to interact with rotavirus and reduce its infectivity

The heat shock cognate protein hsc70 has been implicated as a postattachment cell receptor for rotaviruses. Here we show that hsc70 interacts specifically with rotaviruses through its peptide-binding domain, since a recombinant full-length hsc70 protein and its peptide-binding domain, but not its ATPase domain, bound triple-layered particles in a solid-phase assay, and known ligands of hsc70 competed this binding. The peptide ligands of hsc70 were also shown to block rotavirus infectivity when added to cells before virus infection, suggesting that hsc70 on the surface of MA104 cells also interacts with the virus through its peptide-binding domain and that this interaction is important for virus entry. When purified infectious virus was incubated with soluble hsc70 in the presence of the cochaperone hsp40 and ATP and then pelleted through a sucrose cushion, the recovered virus had lost 60% of its infectivity, even though hsc70 was not detected in the pellet fraction. The hsc70-treated virus showed slightly different reactivities with monoclonal antibodies and was more susceptible to heat and basic pHs than the untreated virus, suggesting that hsc70 induces a subtle conformational change in the virus that results in a reduction of its infectivity. The relevance of the ATPase activity of hsc70 for reducing virus infectivity was demonstrated by the finding that in the presence of a nonhydrolyzable analogue of ATP, virus infectivity was not affected, and a mutant protein lacking ATPase activity failed to reduce virus infection. Altogether, these results suggest that during cell infection, the interaction of the virus with hsc70 on the surface of MA104 cells results in a conformational change of virus particles that facilitates their entry into the cell cytoplasm.     

Genetic structure of Africanized honeybee populations (Apis mellifera L.) from Brazil and Uruguay viewed through mitochondrial DNA COI-COII patterns

Mitochondrial genotypes of Africanized honeybees from Brazil and Uruguay were surveyed by DraI restriction of the COI-COII region. Eleven mitotypes were found, three of which had not previously been described (A28-A30). Out of 775 samples (725 from Brazil, 50 from Uruguay), 197 were A1 and 520 were A4. A1 frequency increases toward the north of Brazil, whereas A4 frequency increases toward the south, a pattern echoing the African distribution. The origin of the A4 and most of the A1 African patterns can be attributed to the introduction of Apis mellifera scutellata into Brazil in 1956. The A29 and A30 patterns have the P1 sequence observed in many Iberian Peninsula samples, which represent the traces of the introductions into Brazil and Uruguay by settlers.     

An experimental study of bamboo ants in western Amazonia

Numerous ant taxa naturally inhabit stems of live and dead Guadua bamboo (Bambusoidea, Poaceae) in western Amazonia. In an experiment at the onset of the wet season in Peru’s Manu National Park, we augmented potential nest sites in stems of live bamboo, dead bamboo and dead ca?a brava (Gynerium sagittatum, another woody grass) at five stations within each of ten bamboo patches and ten control areas outside those patches. Each experimental stem possessed three vacant and available internodes, pre-drilled with, respectively, large, small and linear holes, mimicking the range of forms of surveyed natural entrances. After 24 days, approximately 13% of 798 available internodes had been colonized, the majority by fragments of existing colonies. Ignoring entrance type, which did not affect colonization for any species or species group, and censoring non-independent internodes of the same stem, we used individual stems as independent sample units in other tests. One specialist in live bamboo (Camponotus longipilis), and a likely specialist in dead bamboo (Camponotus depressus), were identified based on overrepresentation in bamboo habitat and disproportionate occurrence in live or dead bamboo stems. A third species, Camponotus (Pseudocolobopsis sp.) was more abundant in bamboo areas but colonized both dead bamboo and dead ca?a. Relatively high abundance of standing dead stems in Guadua forests may account for the presence of a dead stem specialist. The experiment missed detecting specialization in one live culm specialist (Camponotus mirabilis), likely due to its failure to simulate conditions required for the species’ unique modes of colony establishment and spread into new culms. Most opportunistic stem nesters colonized dead bamboo at significantly greater rates than dead ca?a, but were either equally well represented in bamboo and control areas, or underrepresented in bamboo habitat. Given low colonization rates overall, underrepresentation in bamboo cannot be attributed to competition from bamboo specialists for nesting space. Rather, it may be due to combined effects of seasonal flooding of bamboo habitat, and greater importance of food limitation, relative to nest site limitation, in that habitat. Received 9 May 2005; revised 25 August 2005; accepted 29 August 2005.     

Tailored recombinant elastin-like polymers for advanced biomedical and nano(bio)technological applications

The genetic engineering of protein-based polymers is a method that enables, in an easy way, the design of complex and highly functional macromolecules. As examples of this approach, different molecular designs are presented, with increasing degree of complexity, showing how the controlled increase in their complexity yields (multi)functional materials with more selected and sophisticated properties. The simplest designs show interesting properties already, but the adequate introduction of given chemical functions along the polymer chain provides an opportunity to expand the range of properties to enhanced smart behavior and self-assembly. Finally, examples are given where those molecular designs further incorporate selected bioactivities in order to develop materials for the most cutting edge applications in biomedicine and nano(bio)technology.     

Early attack and subsequent changes produced in an industrial lignin by a fungal laccase and a laccase-mediator system: an analytical approach

An industrial kraft pine lignin (Indulin AT, KL) was characterized and treated in both aqueous-buffered media and dioxane to water, either with a partially purified laccase from Fusarium proliferatum or with the laccase plus 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulfonic-acid (ABTS) as mediator. The changes in the lignin after different incubation periods were analyzed through the application of high performance liquid chromatography (HPLC), UV–visible (Vis) spectroscopy and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). At the onset of incubation, laccase-treated samples showed a slight polymerization and strong modifications in UV–Vis spectra. Through Py-GC/MS, a decrease in phenolic and methoxy-bearing pyrolysis products was observed, in contrast to an increase in the more oxidized products. After longer incubation periods (48 h) a substantial polymerization was detected by HPLC, along with a decrease in the guaiacyl (G) units. In contrast, the analysis by HPLC of the samples recovered from the laccase-ABTS system (LMS) showed an intense depolymerization, accompanied by a sizeable loss in G units and a decrease in the methyl and ethyl side-chain phenolic compounds. These results provide conclusive evidence of a rapid initial attack of the industrial lignin by laccase and notable modifications in the KL after longer incubation periods with laccase or LMS.     

Morphology and anatomy of the Cephalocereus columna-trajani cephalium: why tilting?

The morphology and anatomy of the Cephalocereus columna-trajani flowering region was described and compared with data on other species. The vegetative and reproductive regions were described in detail. The results showed that after the flowering region is differentiated, morphological changes take place which are correlated with anatomical changes. The flowering region in this species is termed a lateral cephalium because of its reduced interareolar space, increased areole size and abundant long bristles and trichomes in the areoles. Periderm development near the apical meristem, lack of chlorenchyma and a delay in xylem fiber differentiation are also traits characteristic of a lateral cephalium. The lateral cephalium of C. columna-trajani shared the same combination of morpho-anatomical characters with its sister taxon, C. senilis, except for the number of ribs in the cephalium. Both species survive in high temperature environments and their cephalium faces north; however, only C. columna-trajani tilts, thus we hypothesize that incorporation of fewer ribs associated with periderm development in the cephalium contributes to stem tilting.