Inclusion of South American samples reveals new population structuring of the blacktip shark (Carcharhinus limbatus) in the western Atlantic

Carcharhinus limbatus has a cosmopolitan distribution and marked genetic structuring, mainly because of its philopatric behavior. However, analysis of this structuring has not previously included South American populations. In the present study, we analyzed a sample of adult individuals collected on the northern coast of Brazil and compared the sequences of the mitochondrial control region with those of populations already genotyped. Relatively high haplotype diversity (12 haplotypes, genetic diversity of 0.796) was observed, similar to that in other populations but with a much larger number of private alleles. In contrast to populations studied previously, which were represented by neonates, the pronounced allelic variability found in the South American individuals may have resulted from migrations from other populations in the region that have yet to be genotyped. This population was also genetically distinct from the other Atlantic populations (F_st > 0.8), probably because of female philopatry, and apparently separated from the northwestern Atlantic group 1.39 million years ago. These findings indicate that the C. limbatus population from northern Brazil is genetically distinct from all other populations and should be considered as a different management unit for the protection of stocks.     

A Comovirus Infecting Rocket (Eruca sativa) in Brazil

A virus related to Radish mosaic virus and Turnip ringspot virus (TuRSV) was found infecting rocket plants in Brazil. Predicted amino acids from partial viral RNA sequences placed it closer to TuRSV. We describe here the identification and partial characterization of the first comovirus found infecting a crucifer species in Brazil.     

Monitoring a Puma (Puma concolor) Population in a Fragmented Landscape in Southeast Brazil

ABSTRACT The northeast area of São Paulo state has been intensively deforested, resulting in a highly fragmented landscape composed of a few large patches and several small patches of natural vegetation surrounded by sugarcane, eucalyptus, and citrus plantations. In this scenario, we investigated the puma (Puma concolor) population size, sex ratio, and relatedness in two of the last, and largest, natural refuges in the area using a noninvasive method during 2004–2008. By collecting and individualizing fecal samples by microsatellites, we identified 17 individuals, 13 females (76.4%) and 4 males (23.6%) in these areas. Five females were sampled in distinct years and over an extended time and probably represented resident adults. By investigating the relatedness among individual pumas inhabiting the area, we found that only three animals were not related to each other. We also found evidence that young females might establish an adjacent or overlapping territory to their mothers (phylopatry). Moreover, we registered 11 road‐killed individuals nearby the study area, ten males and one female, and six human–puma conflicts. The study area may act as a source of individuals that disperse across the matrix to occupy new home ranges, maintaining some degree of gene flow in a source–sink metapopulation structure. Finally, we recommend that puma management should be conducted at the landscape level to provide effective puma conservation in northeastern São Paulo state. Abstract in Portuguese is available in the online version of this article.     

ANALYSIS OF ALEXANDRIUM TAMARENSE (DINOPHYCEAE) GENES REVEALS THE COMPLEX EVOLUTIONARY HISTORY OF A MICROBIAL EUKARYOTE1

Microbial eukaryotes may extinguish much of their nuclear phylogenetic history due to endosymbiotic/horizontal gene transfer (E/HGT). We studied E/HGT in 32,110 contigs of expressed sequence tags (ESTs) from the dinoflagellate Alexandrium tamarense (Dinophyceae) using a conservative phylogenomic approach. The vast majority of predicted proteins (86.4%) in this alga are novel or dinoflagellate‐specific. We searched for putative homologs of these predicted proteins against a taxonomically broadly sampled protein database that includes all currently available data from algae and protists, and reconstructed a phylogeny from each of the putative homologous protein sets. Of the 2,523 resulting phylogenies, 14%–17% are potentially impacted by E/HGT involving both prokaryote and eukaryote lineages, with 2%–4% showing clear evidence of reticulate evolution. The complex evolutionary histories of the remaining proteins, many of which may also have been affected by E/HGT, cannot be interpreted using our approach with currently available gene data. We present empirical evidence of reticulate genome evolution that combined with inadequate or highly complex phylogenetic signal in many proteins may impede genome‐wide approaches to infer the tree of microbial eukaryotes.     

Competing regression models for longitudinal data

The choice of an appropriate family of linear models for the analysis of longitudinal data is often a matter of concern for practitioners. To attenuate such difficulties, we discuss some issues that emerge when analyzing this type of data via a practical example involving pretest–posttest longitudinal data. In particular, we consider log‐normal linear mixed models (LNLMM), generalized linear mixed models (GLMM), and models based on generalized estimating equations (GEE). We show how some special features of the data, like a nonconstant coefficient of variation, may be handled in the three approaches and evaluate their performance with respect to the magnitude of standard errors of interpretable and comparable parameters. We also show how different diagnostic tools may be employed to identify outliers and comment on available software. We conclude by noting that the results are similar, but that GEE‐based models may be preferable when the goal is to compare the marginal expected responses.     

Ocurrence of Dyscinetus rugifrons Burmeister (Scarabaeidae: Dynastinae, Cyclocephalini) in Australian palm (Archontophoenix spp. H. Wendl. & Drude) plantations, in Vale do Itajaí, Santa Catarina State, Brazil

For the first time in the Vale do Itajaí, Santa Catarina State, was registered the occurrence of Dyscinetus rugifrons (Burmeister) attacking plantations of Archontophoenix spp. The insect was observed in the Barra do Sul city, causing damages in young plants. The attack caused plant death and in the surveyed area 45% of the plants were attacked. The importance in keeping Archontophoenix spp. plantations is that it is an alternative to palmito-ju?ara (Euterpe edulis) harvesting, a native specie that has its regeneration compromised for the illegal extrativism.     

Effect of tamoxifen and retinoic acid on bradykinin induced proliferation in MCF‐7 cells

Chemopreventive approaches for the treatment of breast cancer have been validated clinically and with in vitro studies. The combined action of tamoxifen/all‐trans retinoic acid was advantageous in MCF‐7 cells, reducing cell proliferation, Bcl‐2 and c‐Myc protein levels and increasing E‐Cadherin protein levels and Gap junctional Intercellular Communication. We further investigated their combined effect in the presence of bradykinin, a pro‐inflammatory agent, previously reported to contribute to the proliferation of breast cancer cells. Bradykinin increased MCF‐7 cell proliferation, c‐Myc levels and ERK1/2 activity. The co‐incubation of bradykinin‐MCF‐7 cells with tamoxifen/all‐trans retinoic acid reduced cell proliferation, ERK1/2 activity, as well as Bcl‐2, c‐Myc, and bradykinin receptor‐2 levels, without altering the enhanced E‐cadherin levels induced by tamoxifen/all‐trans retinoic acid. We showed that the anti‐tumoral effect of tamoxifen/all‐trans retinoic acid is beneficial in MCF‐7 breast cancer cells grown in a bradykinin‐pro‐mitogenic environment, an effect that might be, at least in part, through the MAPK pathway and B2‐bradykinin receptor inhibition. J. Cell. Biochem. 106: 473–481, 2009. © 2008 Wiley‐Liss, Inc.     

Model for prebiotic pyrophosphate formation: Condensation of precipitated orthophosphate at low temperature in the absence of condensing or phosphorylating agents

Summary The formation of pyrophosphate (PPi) by condensation of orthophosphate (Pi) at low temperature (37°C) in the absence of condensing or phosphorylating agents could have been an ancient process in chemical evolution. In the present investigation the synthesis of³²PPi from³²Pi was carried out at pH 8.0 and PPi was found in larger amounts in the presence of insoluble Pi (with calcium or manganese ions) than in its absence (with magnesium ions, or with no divalent cations present). After 10 days of incubation in the presence of precipitated calcium phosphate, about 1.6 nmol/ml of PPi was formed (0.057% yield relative to insoluble Pi). The hypothesis that the reaction is dependent on precipitated Pi was reinforced by the effect of adding dimethyl sulfoxide (2.1–9.9 M) in the presence of magnesium ions: the amount of magnesium phosphate precipitated in the presence of the organic solvent was proportional to the amount of PPi formed. The large and negative activation entropies found in aqueous media with calcium ions and in a medium containing 11.3 M dimethyl sulfoxide with magnesium ions suggest that the reaction was favored by a hydrophobic phenomenon at the surface of solid Pi. This reaction could serve as a model for prebiotic formation of PPi.     

Monocytes modulate the in vitro basal frequency of sister chromatid exchanges of plasma leukocyte cultures and mitotic activity of suppressor-cytotoxic T8 human lymphocytes

The effect of monocytes (MNs) on baseline SCEs and kinetics of human lymphocytes in plasma leukocyte (PLCs) and whole blood cultures (WBCs) was studied. Baseline SCEs in PLCs were nearly two-fold over WBCs. No differences in SCEs were observed between PLCs and MN-depleted PLCs, indicating that SCEs from PLCs are independent of MNs. MNs titration into PLCs decreased proportionally SCEs. Reconstitution of depleted PLCs with concentration of MNs equivalent or higher than those of PLC decreased SCEs. No variations of lymphocyte kinetics in PLCs were observed in the absence/presence of MNs. The proportion of B and T-cell subsets among interphasic lymphocytes were similar in PLC in the absence/presence of MNs, but a significant increase in the proportion of mitotic T8 lymphocytes was observed. Accordingly, MNs modulate both the in vitro basal SCEs and the mitotic activity of T8, but not their cell-cycle kinetics.     

<Emphasis Type=Italic>Zeuxine strateumatica</Emphasis> (Orchidaceae) goes south: a first record for Brazil

Zeuxine strateumatica (L.) Schltr. is recorded for the first time in South America, in S?o Paulo State (Brazil), the southernmost record for the species. It also occurs in Asia, northern Oceania, North America and the Caribbean. A historical record of the geographical expansion of Z. strateumatica is outlined with emphasis on the New World.