Geographic Patterns of Genetic Variation in a Broadly Distributed Marine Vertebrate: New Insights into Loggerhead Turtle Stock Structure from Expanded Mitochondrial DNA Sequences

Previous genetic studies have demonstrated that natal homing shapes the stock structure of marine turtle nesting populations. However, widespread sharing of common haplotypes based on short segments of the mitochondrial control region often limits resolution of the demographic connectivity of populations. Recent studies employing longer control region sequences to resolve haplotype sharing have focused on regional assessments of genetic structure and phylogeography. Here we synthesize available control region sequences for loggerhead turtles from the Mediterranean Sea, Atlantic, and western Indian Ocean basins. These data represent six of the nine globally significant regional management units (RMUs) for the species and include novel sequence data from Brazil, Cape Verde, South Africa and Oman. Genetic tests of differentiation among 42 rookeries represented by short sequences (380 bp haplotypes from 3,486 samples) and 40 rookeries represented by long sequences (∼800 bp haplotypes from 3,434 samples) supported the distinction of the six RMUs analyzed as well as recognition of at least 18 demographically independent management units (MUs) with respect to female natal homing. A total of 59 haplotypes were resolved. These haplotypes belonged to two highly divergent global lineages, with haplogroup I represented primarily by CC-A1, CC-A4, and CC-A11 variants and haplogroup II represented by CC-A2 and derived variants. Geographic distribution patterns of haplogroup II haplotypes and the nested position of CC-A11.6 from Oman among the Atlantic haplotypes invoke recent colonization of the Indian Ocean from the Atlantic for both global lineages. The haplotypes we confirmed for western Indian Ocean RMUs allow reinterpretation of previous mixed stock analysis and further suggest that contemporary migratory connectivity between the Indian and Atlantic Oceans occurs on a broader scale than previously hypothesized. This study represents a valuable model for conducting comprehensive international cooperative data management and research in marine ecology.     

Ein Beitrag zur Biologie einiger aphidivorer Entomophthoraceen

Ohne Zusammenfassung     

Utilization of orange peel,a food industrial waste,in the production of exo-polygalacturonase by pellet forming <Emphasis Type="Italic">Aspergillus sojae</Emphasis>

The production of exo-polygalacturonase (exo-PG) from orange peel (OP), a food industrial waste, using Aspergillus sojae was studied in submerged culture. A simple, low-cost, industrially significant medium formulation, composed of only OP and (NH₄)₂SO₄ (AS) was developed. At an inoculum size of 2.8 × 10³ spores/mL, growth was in the form of pellets, which provided better mixing of the culture broth and higher exo-PG activity. These pellets were successfully used as an inoculum for bioreactors and 173.0 U/mL exo-PG was produced. Fed-batch cultivation further enhanced the exo-PG activity to 244.0 U/mL in 127.5 h. The final morphology in the form of pellets is significant to industrial fermentation easing the subsequent downstream processing. Furthermore, the low pH trend obtained during this fermentation serves an advantage to fungal fermentations prone to contamination problems. As a result, an economical exo-PG production process was defined utilizing a food industrial by-product and producing high amount of enzyme.     

Positive impact of levetiracetam on emotional learning and memory in naive mice

AimsThe effect of an antiepileptic drug on cognitive function is of primary importance with respect to the patient's quality of life. Levetiracetam (LEV) is a novel antiepileptic drug used to treat epilepsy, but its effects on spatial and emotional learning and memory are not yet well understood. The goal of our study was to establish the effects of LEV (17 and 54 mg/kg, intraperitoneally (IP)) on spatial memory retrieval in the Morris water maze test and on acquisition and memory formation in the passive avoidance (PA) test in naive mice.Main methodsThe subjects were adult male BALB/c mice. Spatial learning and memory was established with the Morris water maze (MWM) test. The ‘time spent in escape platforms quadrant’ and the ‘distance to platform’ analyses were measured using a video tracking system to determine spatial memory function. Emotional learning and memory were determined with a one-trial, step-through passive avoidance test.Key findingsIn the MWM test, LEV (17 and 54 mg/kg) neither affected the time spent in the target quadrant nor altered the distance to platform. Moreover, LEV had no effect on swim speed. In the PA task, LEV (17 and 54 mg/kg) significantly prolonged retention latency.SignificanceOur results indicate that LEV did not alter spatial memory retrieval in the MWM test, but it did show some ameliorating effects on acquisition and memory formation in the PA test in naive mice.     

Electrochemical based detection of microRNA, mir21 in breast cancer cells

Hemagglutinin (HA) is a trimeric glycoprotein expressed on the influenza virus membrane. HA of influenza viruses binds to the host's cell surface complex glycans via a terminal sialic acid (Sia), as the first key step in the process of infection, transmission and virulence of influenza viruses. It is important to monitor and evaluate the receptor (glycan) binding preferences of the HAs derived from influenza A viruses, especially those originating from birds and swine, to understand their potential ability for interspecies transmission. From this viewpoint, in the present study, we have developed a protocol for analyzing the glycan-HA interactions efficiently and kinetically, based on surface plasmon resonance (SPR). Our results showed that glycan-HA binding analyses can be performed reliably and efficiently on Biacore-chips in the SPR system, using chemically synthesized biotinylated multivalent-glycans. Using the CAP-chip, we were able to regenerate the surface for multiple analyses, allowing us to derive, for the first time, the precise kinetic parameters for different HA-glycan complexes of newly emerging influenza viruses. These studies suggested that this SPR-based method is suitable for influenza surveillance to define the pandemic scenario as well as to screen of synthetic glycans and other compounds that may interfere with glycan-HA interactions.     

TonEBP/OREBP is a regulator of nucleus pulposus cell function and survival in the intervertebral disc

The nucleus pulposus is an aggrecan-rich hydrated tissue that permits the intervertebral disc to resist compressive loads. Adaptation to loading is achieved through an elevation in disc osmolarity mediated by the numerous charged glycosoaminoglycan side chains of the aggrecan molecule. The goal of this investigation was to determine the functional role of the osmo-regulatory protein, TonEBP, in cells of the nucleus pulposus. We found that TonEBP and its downstream target genes were robustly expressed in the tissues of the disc. Above 330 mosmol/kg, cultured nucleus pulposus cells up-regulated target genes TauT, BGT-1, and SMIT; above 450 mosmol/kg, there was raised expression of HSP-70. In hypertonic media there was activation of TauT and heat shock protein-70 (HSP-70) reporter activity and increased binding of TonEBP to the TonE motif. When cells were transfected with the dominant-negative form of TonEBP (DN-TonEBP) there was suppression of TauT and HSP-70 reporter gene expression; pTonEBP enhanced reporter gene expression. Moreover, in hypertonic media, forced expression of DN-TonEBP induced apoptosis. We suppressed TonEBP using small interfering RNA technique and noted a decrease in TauT reporter activity in isotonic as well as hyperosmolar media. Finally, we report that the aggrecan promoter contains two conserved TonE motifs. To evaluate the importance of these motifs, we overexpressed DN-TonEBP and partially silenced TonEBP using small interfering RNA. Both approaches resulted in suppression of aggrecan promoter activity. It is concluded that TonEBP permits the disc cells to adapt to the hyperosmotic milieu while autoregulating the expression of molecules that generate the unique extracellular environment.     

Blood rheology of Weddell seals and bowhead whales

Red blood cell (RBC) aggregation and blood viscosity are important determinants of in vivo blood flow dynamics and, in marine mammals, these parameters may impact diving physiology by altering blood oxygen delivery during the diving response. Weddell seals are superb divers and exhibit age-related patterns in blood oxygen chemistry and diving ability. By contrast, bowhead whales are not long duration divers, and little is known of their blood properties relative to diving. The present study was designed to compare rheological characteristics of blood from Weddell seal pups, Weddell seal adults, and from adult bowhead whales: blood viscosity and RBC aggregation in plasma and in polymer solutions (i.e., RBC "aggregability") were measured. Salient findings included: (1) significant 4- to 8-fold greater aggregation in blood from adult seals compared with pups and human subjects; (2) 2-to 8-fold greater aggregation in bowhead whale blood compared with human blood; (3) compared to human red cells, enhanced RBC aggregability of RBC from adult seals and whales as determined by their greater aggregation in polymer solutions; (4) increasing RBC aggregation and aggregability of seal pup blood over a seven day period following birth; (5) significantly greater blood viscosity for adult seals compared with pups at both native and standardized hematocrits. These results indicate that, for both species, hemorheological parameters differ markedly from those of humans, and suggest progressive changes with seal age; the physiological implications of these differences have yet to be fully defined.