In vitro sperm penetration through the zona pellucida of immature and in vitro matured oocytes using fresh, chilled and frozen canine semen

The aim of this study was to evaluate the effect of sperm cryopreservation and the maturation state of the oocyte on the time course of canine gamete interaction during co-culture for periods of 1-10 h. Semen samples were obtained by digital stimulation and ejaculates processed as fresh, chilled and frozen samples. Sperm were co-cultured with immature or in vitro mature bitch oocytes for up to 10 h. At hourly intervals, oocytes were evaluated for sperm penetration with epifluorescence microscopy. The results were analyzed statistically using generalized linear models. Spermatozoa treatments had a significant effect on the total percentage of oocyte penetration for both types of oocytes; fresh spermatozoa showed the highest average penetration rate, while frozen sperm showed the lowest value (p<0.05). At the 1st hour of co-culture, chilled and frozen dog sperm had a higher penetration percentage (p<0.05) of in vitro matured canine oocytes (43.6% and 45.7%, respectively) than the fresh sperm had (33.8%). Sperm penetration was directly proportional to the time of incubation, when fresh or chilled sperm were used (P<0.05); in contrast, frozen dog sperm did not change penetration rates with either immature or in vitro matured oocytes over time. There was a significant difference in the average of penetration rate between immature (47.3%) and in vitro matured oocytes (56.6%) throughout the 10h of culturing; irrespective of sperm treatment. The optimal incubation time in terms of maximizing penetration rates probably are dependent on how spermatozoa were processed prior to fertilization.     

Viremia and antibody response in green monkeys (Chlorocebus aethiops sabaeus) infected with dengue virus type 2: A potential model for vaccine testing

The increasingly limited availability and high cost of the hitherto most commonly used monkey species in dengue vaccine research has augmented the importance of identifying alternative suitable models for these studies. In this study we examined the capacity of green monkeys ( Chlorocebus aethiops sabaeus ) to develop dengue viremia, and thus provide a potential model for dengue vaccine testing. Monkeys were inoculated with two different doses of dengue virus type 2. All animals in both groups became viremic after inoculation of the virus. In the lower dose group, mean viremia duration of 5.66 days was detected, whereas in the group that received the 10⁶ PFU dose, viremia had a mean duration of only 1.66 days. Antibody titers were similar to those obtained in previous experiments with rhesus and cynomolgus macaques. We conclude that green monkeys develop viremia and antibody responses and therefore provide a potential model for the preclinical evaluation of novel candidates for dengue vaccines.     

Synopsis of a new collection of sea spiders (Arthropoda: Pycnogonida) from the Ross Sea,Antarctica

The biodiversity research expedition TAN0204 with RS Tangaroa to the Ross Sea in 2004 yielded a new collection of 2,687 specimens of pycnogonids. As much as 25 different species encompassing 14 genera and eight families were identified and their records are discussed herein. The collection is archived in the Marine Invertebrate Collection of the New Zealand National Institute of Water and Atmospheric Research (NIWA). The majority (69%) of specimens are from the Nymphon australe group (Nymphonidae), although species richness and abundance varied among the stations sampled. The collection includes several specimens from polymerous taxa; Pentanymphon antarcticum (Nymphonidae), Decolopoda australis (Colossendeidae) and Pentapycnon bouvieri (Pycnogonidae). All species were classified based on morphological characters, and DNA sequences (from the 18S, 12S, 16S and COI regions) for 21 of the representative morphotypes are given. The DNA sequences confirmed the species-level distinctiveness of these morphotypes. No species new to science were identified, although further detailed morphometric and/or molecular analyses may reveal cryptic or sibling species, especially in species such as the highly abundant Nymphon australe group. An erratum to this article can be found at     

Analysis of electrostatic contributions to the selectivity of interactions between RING-finger domains and ubiquitin-conjugating enzymes

The zinc-coordinated protein motifs known as RING-finger domains, present on a class of ubiquitin ligases (E3's), recruit ubiquitin-conjugating enzymes (E2s), tethering them to substrate proteins for covalent modification with ubiquitin. Each RING-finger domain can recruit different E2s, and these interactions are frequently selective, in that certain RING-finger domains associate preferentially with certain E2s. This selectivity acquires particular biological relevance when the recruited E2s exert specialized functions. We have explored the determinants that specify the presence or absence of experimentally detectable interaction between two RING-finger domains, those on RNF11 and RNF103, and two E2s, UBC13, a specialized E2 that catalyzes ubiquitin chain elongation through Lys63 of ubiquitin, and UbcH7, which mediates polyubiquitylation through Lys48. Through the iterative use of computational predictive tools and experimental validations, we have found that these interactions and their selectivity are partly governed by the combinations of electrostatic interactions linking specific residues of the contact interfaces. Our analysis also predicts that the main determinants of selectivity of these interactions reside on the RING-finger domains, rather than on the E2s. The application of some of these rules of interaction selectivity has permitted us to experimentally manipulate the selectivity of interaction of the RING-finger domain-E2 pairs under study.     

Effects of parasitic infection and radio-transmitters on condition, hematological characteristics and corticosterone concentrations in Texas ratsnakes

Parasites are a health concern of many wildlife species, although their effect on reptiles is poorly studied. Here we examine effects of hemogregarine and external parasites on Texas ratsnake Elaphe obsoleta white blood cell (WBC) concentrations, WBC differentials, heterophil/lymphocyte ratios, packed cell volume (PCV), corticosterone concentrations and body condition. We found little evidence that either ectoparasites or hemogregarines affected the health of Texas ratsnakes. We found a seasonal increase in corticosterone, consistent with glucocorticoids priming the snakes to deal with higher predation risks later in the season. We also examined whether the potential stress of carrying a surgically implanted radio-transmitter compounds any parasitic health effects. We found no effect of transmitters on most aspects of health. We did find equivocal evidence that WBC concentrations were higher in snakes with transmitters and that PCV decreased following transmitter implantation. Although our results generally support the view that data collected using radio-telemetry are unlikely to be biased due to adverse health effects of transmitters, the growing importance of telemetry for studies of snakes and other taxa argues for further research on this topic. When possible, researchers should design telemetry studies in such a way that assessing potential heath effects of transmitters is one of the objectives.     

Understanding investment in biodiversity conservation in Mexico

Documenting financial resources in biodiversity conservation is a key aspect worldwide in order to set priorities and use effectively the limited resources available. In Mexico, a megadiverse country, studies on financial resources invested in biodiversity conservation are scarce and do not address funding for conservation comprehensively. Using recent data from several sources and applying criteria based on the national priorities for conservation, we compiled, systematized and analyzed data at a national scale on financing sources, financial resources and conservation organizations and their projects. The information obtained is presented in various ways and part of it (case study) is already an information system that can be continuously up-dated. Some of the results show the following: a steady diversification of mechanisms and methods for raising funds for conservation; an increase in governmental budgets; the acknowledgment by the private sector of the importance of biodiversity conservation; a greater technical capacity in people and organizations working in conservation; a greater accessibility of financial resources to support and maintain conservation projects; yet a short term vision in conservation projects; among other. Although the results obtained through this study are a first approach, they can now be used as a baseline to continue gathering and analyzing information on conservation financing in Mexico.     

Adiponectin upregulates monocytic activin A but systemic levels are not altered in obesity or type 2 diabetes

Adiponectin is an adipocyte-derived protein with atheroprotective and immunoregulatory function. Adiponectin and activin A reduce foam cell formation and adiponectin activates the p38 MAPK pathway that is well described to induce activin A. Therefore, it was analyzed whether adiponectin alters activin A in primary human monocytes. Adiponectin dose- and time-dependently induced activin A in the supernatant, and the maximal amount was observed after 12 h of incubation. Adiponectin-stimulated release of activin A was blocked by a p38 MAPK inhibitor. Metformin and pioglitazone are drugs frequently used to treat diabetic patients and metformin slightly reduced monocytic activin A release whereas pioglitazone had no effect. Type 2 diabetes is associated with elevated inflammatory systemic cytokines but activin A serum levels were similar in slim probands, overweight controls and type 2 diabetic patients. Furthermore, activin A did not correlate to systemic adiponectin, body mass index, waist to hip ratio or C-reactive protein. These findings indicate that adiponectin upregulates monocytic activin A release via the p38 MAPK pathway, and this may in part explain the immunoregulatory and antiatherosclerotic effects of this adipokine.     

Studies on toll-like receptor stimuli responsiveness in HIV-1 and HIV-2 infections

Background: HIV-1 and HIV-2 are two related viruses with distinct clinical outcomes, where HIV-1 is more pathogenic and transmissible than HIV-2. The pathogenesis of both infections is influenced by the dysregulation and deterioration of the adaptive immune system. However, their effects on the responsiveness of innate immunity are less well known. Here, we report on toll-like receptor (TLR) stimuli responsiveness in HIV-1 or HIV-2 infections. Methods: Whole blood from 235 individuals living in Guinea-Bissau who were uninfected, infected with HIV-1, infected with HIV-2, and/or infected with HTLV-I, was stimulated with TLR7/8 and TLR9 agonists, R-848 and unmethylated CpG DNA. After TLR7/8 and TLR9 stimuli, the expression levels of IL-12 and IFN-α were related to gender, age, infection status, CD4⁺ T cell counts, and plasma viral load. Results: Defective TLR9 responsiveness was observed in the advanced disease stage, along with CD4⁺ T cell loss in both HIV-1 and HIV-2 infections. Moreover, TLR7/8 responsiveness was reduced in HIV-1 infected individuals compared with uninfected controls. Conclusions: Innate immunity responsiveness can be monitored by whole blood stimulation. Both advanced HIV-1 and HIV-2 infections may cause innate immunity dysregulation.