An ESR study of nitrosyl-Aplysia brasiliana myoglobin and nitrosyl annelidae Glossoscolex paulistus erythrocruorin

The nitrosyl derivatives of Annelidae Glossoscolex paulistus hemoglobin (an earth worm erythrocruorin (Ec AGp)) and Aplysia brasiliana myoglobin (Mb Apb) are studied using ESR spectroscopy. These two proteins have a quite similar ESR spectra at 100 K, but a different temperature behaviour. The temperature dependence of the nitrosyl Mb Apb spectrum is in good agreement with the Boltzmann distribution. In the case of nitrosyl-Ec AGp, the results are explained by the existence of two types of spectrum in thermodynamic equilibrium, with delta H = 9.08 kJ/mol, delta S = 47.15 J/mol and T1/2 = 193 K. There is a great similarity of the nitrosyl-Ec AGp spectra with those reported for elephant myoglobin, suggesting the presence of the same heme environment with a glutamine residue in the distal site. The pH dependence of the spectrum of nitrosyl-Mb Apb shows that the affinity of nitrosyl binding is higher at high pH (7.3) than at low pH (4.6). The ESR parameters are the same for these two pH values.     

Allosteric effect of protons and adenosine triphosphate on hemoglobins from aquatic amphibia

Summary The analysis of hemoglobins from two anurans, one semi-aquatic (Leptodactylus labyrinthicus) and the other aquatic (Pipa carvalhoi), showed several components isolated by CM-cellulose chromatography. The two major components (Hb II and Hb III) ofL. labyrinthicus and the major components (Hb III and Hb IV) ofP. carvalhoi possess functional properties as follows: i.P. carvalnoi Hb III and Hb IV andL. labyrinthicus Hb II had very small Bohr effects (–0.05) and a substantial heterotropic effect with polyphosphates. ii.L. labyrinthicus Hb III produced a normal Bohr effect of –0.17, with no influence of polyphosphates.The authors wish to dedicate this paperin memoriam of Prof. Eraldo Antonini who contributed much to the knowledge of hemoglobins     

Trypanosoma cruzi: distribution of fluorescently labeled tubulin and actin in epimastigotes

Cytoskeletal components were visualized in epimastigote forms of Trypanosoma cruzi by double immunofluorescence microscopy using monospecific antibodies against tubulin and against actin. Intense staining of the flagellum and the edges of the cell body was observed when the cells were stained with anti-tubulin, reflecting the presence of the basal bodies, the flagellar axoneme and the subpellicular microtubules. A less intense staining was seen in the cell body of epimastigotes stained with anti-actin. However, an intense staining was observed with this antibody in the flagellum, in a pattern similar to that observed with anti-tubulin. It is suggested that the paraxial structure, which is formed by a complex array of 6-nm-thick microfilaments is composed, at least in part, of actin.     

MAC-T Cells as a Tool to Evaluate Lentiviral Vector Construction Targeting Recombinant Protein Expression in Milk

Prior to generating transgenic animals for bioreactors, it is important to evaluate the vector constructed to avoid poor protein expression. Mammary epithelial cells cultured in vitro have been proposed as a model to reproduce the biology of the mammary gland. In the present work, three lentiviral vectors were constructed for the human growth hormone (GH), interleukin 2 (IL2), and granulocyte colony-stimulating factor 3 (CSF3) genes driven by the bovine β-casein promoter. The lentiviruses were used to transduce mammary epithelial cells (MAC-T), and the transformed cells were cultured on polystyrene in culture medium with and without prolactin. The gene expression of transgenes was evaluated by PCR using cDNA, and recombinant protein expression was evaluated by Western-blotting using concentrated medium and cellular extracts. The gene expression, of the three introduced genes, was detected in both induced and non induced MAC-T cells. The human GH protein was detected in the concentrated medium, whereas CSF3 was detected in the cellular extract. Apparently, the cellular extract is more appropriate than the concentrated medium to detect recombinant protein, principally because concentrated medium has a high concentration of bovine serum albumin. The results suggest that MAC-T cells may be a good system to evaluate vector construction targeting recombinant protein expression in milk.     

Fish biodiversity of Saint Peter and Saint Paulʼs Archipelago,Mid-Atlantic Ridge,Brazil: new records and a species database

Saint Peter and Saint Paul's Archipelago (SPSPA), one of the smallest and most isolated island groups in the world, is situated on the Mid-Atlantic Ridge, between Brazil and the African continent. SPSPA has low species richness and high endemism; nonetheless, the diversity of fishes from deep habitats (>30 m depth) had not been previously studied in detail. Several expeditions conducted between 2009 and 2018 explored the shallow and deep reefs of SPSPA using scuba, closed-circuit rebreathers, manned submersibles, baited remote underwater stereo-videos (stereo-BRUV) and fishing between 0 and 1050 m depth. These expeditions yielded 41 new records of fishes for SPSPA: 9 in open waters, 9 in shallow waters (0–30 m), 8 in mesophotic ecosystems (30–150 m) and 15 in deeper reefs (>150 m). Combined with literature records of adult pelagic, shallow and deep-reef species, as well as larvae, the database of the fish biodiversity for SPSPA currently comprises 225 species (169 recorded as adult fishes and 79 as larvae, with 23 species found in both stages). Most of them (112) are pelagic, 86 are reef-associated species and 27 are deep-water specialists. Species accumulation curves show that the number of fish species has not yet reached an asymptote. Whereas the number of species recorded in SPSPA is similar to that in other oceanic islands in the Atlantic Ocean, the proportion of shorefishes is relatively lower, and the endemism level is the third highest in the Atlantic. Twenty-nine species are listed as threatened with extinction. Observations confirm the paucity of top predators on shallow rocky reefs of the island, despite the presence of several pelagic shark species around SPSPA. Because all of the endemic species are reef associated, it is argued that the new marine-protected areas created by the Brazilian government do not ensure the protection and recovery of SPSPA's biodiversity because they allow exploitation of the most vulnerable species around the archipelago itself. This study suggests a ban on reef fish exploitation inside an area delimited by the 1000 m isobath around the islands (where all known endemics are concentrated) as the main conservation strategy to be included in the SPSPA management plan being prepared by the Brazilian government.     

Mouriri morleyii sp. nov. (Melastomataceae) from Brazil,with notes on its foliar stomatal crypts

Mouriri morleyii R. Goldenb. & Meirelles sp. nov. can be distinguished from the other species in the genus by its large stomatal crypts (the largest ones in the genus), columnar sclereids, tetramerous flowers and calyx closed in bud. This new species was collected on an inselberg in the state of Espírito Santo, Brazil.     

Stranding Events of Kogia Whales along the Brazilian Coast

The genus Kogia, which comprises only two extant species, Kogia sima and Kogia breviceps, represents one of the least known groups of cetaceans in the global ocean. In some coastal regions, however, stranding events of these species have been relatively common over the last decades. Stranding provides the opportunity to investigate the biology of these cetaceans and to explore the epidemiological aspects associated with the mortality of the organisms found on the beach. A number of disturbances (including pelagic fisheries, chemical pollution, boat strikes, and noise pollution) have been confirmed to pose a particular threat to the Kogia species. However, no study has yet investigated potential relationships between environmental conditions and stranding events. Here we analyse how a collection of environmental, physical, and biological variables, such as wind, sea surface temperature (SST), water depth, and chlorophyll-a, correlate to Kogia stranding events along the Brazilian coast. The results of our statistical analyses suggest that K. sima is more likely found in warm tropical waters, which provide an explanation for the high frequency of stranding in northeastern Brazilian coast. In contrast, K. breviceps appears to have a preference for temperate and productive waters. Wind speed results to be also an important factor for predicting Kogia strandings in Brazilian coast. Additionally, literature information in combination with our own data and analyses of stomach contents confirms that oceanic cephalopods constitute the primary nutritional source of both Kogia species. By using the available information as a qualitative proxy for habitat preference and feeding ecology, our study provides a novel and comprehensive assessment of Kogia stranding data in relation to environmental conditions along the Brazilian coast.     

Dynamics of Cattle Production in Brazil

Movement of livestock production within a country or region has implications for genetics, adaptation, well-being, nutrition, and production logistics, particularly in continental-sized countries, such as Brazil. Cattle production in Brazil from 1977 to 2011 was spatialized, and the annual midpoint of production was calculated. Changes in the relative production and acceleration of production were calculated and spatialized using ARCGIS®. Cluster and canonical discriminant analyses were performed to further highlight differences between regions in terms of cattle production. The mean production point has moved from the Center of Minas Gerais State (in the southeast region) to the North of Goiás State (in the Midwest region). This reflects changes in environmental factors, such as pasture type, temperature and humidity. Acceleration in production in the northern region of Brazil has remained strong over the years. More recently, “traditional” cattle-rearing regions, such as the south and southeast, showed a reduction in growth rates as well as a reduction in herd size or internal migration over the period studied. These maps showed that this movement tends to be gradual, with few regions showing high acceleration or deceleration rates.     

Oxygen tension modulates extracellular vesicles and its miRNA contents in bovine embryo culture medium

The biotechnology for in vitro embryo production is becoming increasingly popular, being applied to humans and domestic animals. Embryo development can be achieved with either 20% or 5% oxygen tension. The extracellular vesicles (EVs) are secreted by different cell types and carry bioactive materials. Our objective was to determine the secretion pattern and micro RNA (miRNA) contents of EVs released in the bovine embryo culture environment—embryo and cumulus cell monolayer—on Days 3 and 7 of in vitro culture under two different oxygen tensions: High (20%) and low (5%). The EVs were isolated from the medium and analyzed to determine size, concentration, and miRNA levels. EVs concentration in low oxygen tension increased on Day 3 and decreased on Day 7. Additionally, altered EV miRNAs derived from the embryo‐cumulus culture medium were predicted to regulate survival and proliferation‐related pathways on Days 3 and 7. Moreover, miR‐210 levels decreased in EVs isolated from the culture medium under high oxygen tension suggesting that this miRNA can be used as a marker for normoxia since it is associated with low oxygen tension. In summary, this study provides knowledge of the oxygen tension effects on EVs release and content, and potentially, on cell‐to‐cell communication during in vitro bovine embryo production.