Captive breeding of the barndoor skate (Dipturus laevis) at the Montreal Biodome,with comparison notes on two other captive‐bred skate species

In 1997, the Montreal Biodome obtained five barndoor skates (Dipturus laevis) from the waters off Boston, Massachusetts. Six years later, those specimens began reproducing, and the first egg case was collected in November 2003. Since then, 73 hatchlings have been born and raised. Egg cases were observed year round, and annual fecundity was measured for the first time: one female laid 69 eggs in 2005, 85 in 2006 and 115 in 2007. Egg incubation was longer than believed previously, ranging from 342 to 494 days. Hatching occurred throughout the year. Hatchlings averaged 193 mm total length and 128 mm disk width and weighed 32 g. They were fed krill and diced fish. All but one survived the first month. A photo identification system was useful in recognizing two groups of 10 specimens during their first year, and transponders could be inserted in the wing muscles of 1‐year‐old skates. Total lengths at birth and at age 2 were similar to the data reported from the wild, suggesting a similar growth pattern in captivity. The reproduction characteristics of the barndoor skate were compared with those of two other skate species currently bred at the Montreal Biodome, the winter skate (Leucoraja ocellata) and the thorny skate (Amblyraja radiata). Zoo Biol 27:145–153, 2008. © 2008 Wiley‐Liss, Inc.     

Effects of light and temperature on seed germination of cacti of Brazilian ecosystems

Environmental factors are used by plants as spatio‐temporal indicators of favorable conditions for seed germination. Thus, the objective of this study was to determine the effect of light and temperature on seed germination of 30 taxa of Cactaceae occurring in northeastern Brazil and to evaluate whether fluctuations in temperature are capable of altering light sensitivity. The seeds were tested for germination under two light conditions (12 h photoperiod and continuous darkness) and 10 temperature treatments: eight constant temperatures (10, 15, 20, 25, 30, 35, 40 and 45°C) and two alternating temperatures (30/20°C and 35/25°C). The species studied showed two photoblastic responses. All cacti from the Cactoideae subfamily (22 taxa) were classified as positive photoblastic (i.e., no germination in darkness), regardless of the temperature treatment used. Likewise, temperature fluctuation did not alter the seed sensitivity to light. On the other hand, the species of the Opuntioideae (five taxa) and Pereskioideae (three taxa) subfamilies are indifferent to light (i.e., germinated both in the presence and absence of light). The cacti from the areas of Caatinga and Cerrado showed an optimal germination temperature of 30°C, while the species from Atlantic Forest and Restinga areas showed an optimal germination temperature of 25°C.     

Feeding habits of Lutjanus guttatus (Pisces: Lutjanidae) at Los Cóbanos and Puerto La Libertad, El Salvador

Abstract: A total of 175 spotted snapper Lutjanus guttatus were collected monthly in the Los Cobanos and Puerto La Libertad, El Salvador, from January to December 2000 to determine its feeding habits. The fishes studied ranged 9.8 - 58.0 cm in total length. Were collected using push-net and hook and line. This snapper is a bentonic opportunistic carnivorous predator. The total biomass of the stomach contents was 260.5 g. Crustaceans (Squillidae, Portunidae, Dynomenidae. Penaeidae, Sicyoniidae, Callianassidae), were the most abundant group: they accounted for 50.4% of the total biomass. Numerically, Portunus asper was the most abundant prey. Ontogenic differences were observed in the diet. In juveniles (16 cm TL). at any time of the year, the most frequent and abundant components were crustaceans and in adults were crustaceans, fishes and mollusks. The relative importance of different components of the diet was assessed with two indexes that combine. in different ways. percentage frequency of occurrence, percentage number and percentage weight of prey categories. The commercial use this resource and the absence of management strategies are discussed.     

Protease Activated Receptor-2 Contributes to Heart Failure

Heart failure is a major clinical problem worldwide. Previous studies have demonstrated an important role for G protein-coupled receptors, including protease-activated receptors (PARs), in the pathology of heart hypertrophy and failure. Activation of PAR-2 on cardiomyocytes has been shown to induce hypertrophic growth in vitro. PAR-2 also contributes to myocardial infarction and heart remodeling after ischemia/reperfusion injury. In this study, we found that PAR-2 induced hypertrophic growth of cultured rat neonatal cardiomyocytes in a MEK1/2 and p38 dependent manner. In addition, PAR-2 activation on mouse cardiomyocytes increased expression of the pro-fibrotic chemokine MCP-1. Furthermore, cardiomyocyte-specific overexpression of PAR-2 in mice induced heart hypertrophy, cardiac fibrosis, inflammation and heart failure. Finally, in a mouse model of myocardial infarction induced by permanent ligation of the left anterior descending coronary artery, PAR-2 deficiency attenuated heart remodeling and improved heart function independently of its contribution to the size of the initial infarct. Taken together, our data indicate that PAR-2 signaling contributes to the pathogenesis of hypertrophy and heart failure.     

Sequence and genomic structure of the human adult skeletal muscle sodium channel alpha subunit gene on 17q.

The amino acid sequence of the sodium channel alpha subunit from adult human skeletal muscle has been deduced by cross-species PCR-mediated cloning and sequencing of the cDNA. The protein consists of 1836 amino acid residues. The amino acid sequence shows 93% identity to the alpha subunit from rat adult skeletal muscle and 70% identity to the alpha subunit from other mammalian tissues. A 500 kb YAC clone containing the complete coding sequence and two overlapping lambda clones covering 68% of the cDNA were used to estimate the gene size at 35 kb. The YAC clone proved crucial for gene structure studies as the high conservation between ion channel genes made hybridization studies with total genomic DNA difficult. Our results provide valuable information for the study of periodic paralysis and paramyotonia congenita, two inherited neurological disorders which are caused by point mutations within this gene.     

Pragmatic data and observations related to the epidemiology of Chagas disease

Chagas' disease or American trypanosomiasis is a parasitic zoonosis which constitutes and important public health problem in most of the Latin American countries. According to the development of socio-political events in the world, it is possible at present to speak of rural-periurban Chagas' disease and urban Chagas' disease. Rural-periurban Chagas' disease. In its endemo-enzootic condition it is distributed in vast areas from Mexico in the north and Argentina and Chile in the south. It is calculated that the population at risk is about 90 million persons, not less than 16-18 million are Trypanosoma cruzi infected and approximately 38% of these present or have presented pathology caused by the parasite. Organs most frequently affected: heart, esophagus and colon. The corresponding biological vectors are hematophagus triatomid bugs, with greater than 100 species synantropic (st) or sylvatic (sv), existing between parallels 41 N. and 46 S., but only about 36, which have been found infected, have some relationship with man because their adaptation to human dwelling. The human parasitose is less extended due to the fact that the vectors of the region are predominantly sv. The known reservoirs are more than 180 species of terrestrial mammals: domestic, st and sv. Man is possibly the most important. Some available relevant epidemiological information is summarized as follows: Additionally, some autochthonous cases of T. cruzi human infection have been registered in the United States, Trinidad-Tobago, Guyana and Belize. Moreover, infected vectors and/or sv reservoirs have been observed in almost a dozen of Caribbean countries. Urban Chagas' disease. As a consequence of possible better salaries and many other motivations, in the last decades there have been significant and constant migrations from rural to urban areas in many Latin American countries. This situation has facilitated the dissemination of T. cruzi infection through infected reservoirs--mostly humans--and/or passively transported infected vectors. In most of the cases these rural-urban migrations occur in chagasic endemic areas within a same country or in neighbouring ones; in others, the migration can involve countries where Chagas' disease does not exist, transmission being via blood transfusion or placental. According to some estimates, with a mean rate of 1.5% chagasic infected blood donors the minimum risk of T. cruzi transmission is nearly 12.5-25.0% when the volumen of transfused blood is 500 ml.(ABSTRACT TRUNCATED AT 400 WORDS)     

Arginine substitution by alanine at the P1 position increases the selectivity of CmPI-II,a non-classical Kazal inhibitor

CmPI-II is a Kazal-type tight-binding inhibitor isolated from the Caribbean snail Cenchritis muricatus. This inhibitor has an unusual specificity in the Kazal family, as it can inhibit subtilisin A (SUBTA), elastases and trypsin. An alanine in CmPI-II P1 site could avoid trypsin inhibition while improving/maintaining SUBTA and elastases inhibition. Thus, an alanine mutant of this position (rCmPI-II R12A) was obtained by site-directed mutagenesis. The gene cmpiR12A was expressed in P. pastoris KM71H yeast. The recombinant protein (rCmPI-II R12A) was purified by the combination of two ionic exchange chromatography (1:cationic, 2 anionic) followed by and size exclusion chromatography. The N-terminal sequence obtained as well as the experimental molecular weight allowed verifying the identity of the recombinant protein, while the correct folding was confirmed by CD experiments. rCmPI-II R12A shows a slightly increase in potency against SUBTA and elastases. The alanine substitution at P1 site on CmPI-II abolishes the trypsin inhibition, confirming the relevance of an arginine residue at P1 site in CmPI-II for trypsin inhibition and leading to a molecule with more potentialities in biomedicine.     

Predicting the accuracy of multiple sequence alignment algorithms by using computational intelligent techniques

Multiple sequence alignments (MSAs) have become one of the most studied approaches in bioinformatics to perform other outstanding tasks such as structure prediction, biological function analysis or next-generation sequencing. However, current MSA algorithms do not always provide consistent solutions, since alignments become increasingly difficult when dealing with low similarity sequences. As widely known, these algorithms directly depend on specific features of the sequences, causing relevant influence on the alignment accuracy. Many MSA tools have been recently designed but it is not possible to know in advance which one is the most suitable for a particular set of sequences. In this work, we analyze some of the most used algorithms presented in the bibliography and their dependences on several features. A novel intelligent algorithm based on least square support vector machine is then developed to predict how accurate each alignment could be, depending on its analyzed features. This algorithm is performed with a dataset of 2180 MSAs. The proposed system first estimates the accuracy of possible alignments. The most promising methodologies are then selected in order to align each set of sequences. Since only one selected algorithm is run, the computational time is not excessively increased.