Batrachochytrium dendrobatidis: requirement for further isolate collection and archiving

The fungal pathogen Batrachochytrium dendrobatidis (Bd) causes the disease chytridiomycosis, which is lethal to many species of amphibians worldwide. Many studies have investigated the epidemiology of chytridiomycosis in amphibian populations, but few have considered possible host-pathogen coevolution. More specifically, investigations focused on the evolution of Bd, and the link with Bd virulence, are needed. Such studies, which may be important for conservation management of amphibians, depend on access to Bd isolates. Here we provide a summary of known Bd isolates that have been collected and archived in various locations around the world. Of 257 Bd isolates, we found that 53% originate from ranids in the United States. In many cases, detailed information on isolate origin is unavailable, and it is unknown how many isolates are cryo-archived. We suggest the creation of a centralized database of isolate information, and we urge researchers and managers to isolate and archive Bd to facilitate future research on chytridiomycosis.     

Novel insulin-elicited phosphoproteins in adipocytes

Akt is a key insulin-activated protein kinase. We searched for Akt substrates in 3T3-L1 adipocytes by means of immunoprecipitation with an Akt phosphomotif-specific antibody (PAS antibody). Four insulin-elicited phosphoproteins were isolated and identified by mass spectrometry. The identity of each protein was established by isolating the protein from lysates of untreated and insulin-treated adipocytes with an antibody specific for the protein and showing that the PAS antibody reacted only with the protein in the immunoprecipitate from insulin-treated cells. These proteins have sizes of 47, 75, 105, and 250 kDa on SDS PAGE, and have been designated pp47, 75, 105, and 250. The effect of inhibitors on the phosphorylation of the proteins, the identified sites of phosphorylation, and in vitro phosphorylation by recombinant Akt further indicated that pp47, 105, and 250 are likely to be Akt substrates, whereas pp75 may not be. pp47 and 105 are novel proteins with no known or predicted function. pp75 was previously found as a protein that associated with the colony-stimulating factor receptor, designated as Fms-interacting protein. pp250 is a novel protein with a predicted GTPase activating protein (GAP) domain for Rheb and/or Rap at its carboxy terminus. The subcellular and tissue distributions of the four proteins were determined.     

Identification of human VPS37C, a component of endosomal sorting complex required for transport-I important for viral budding

Endosomal sorting complex required for transport-I (ESCRT-I) is one of three defined protein complexes in the class E vacuolar protein sorting (VPS) pathway required for the sorting of ubiquitinated transmembrane proteins into internal vesicles of multivesicular bodies. In yeast, ESCRT-I is composed of three proteins, VSP23, VPS28, and VPS37, whereas in mammals only Tsg101(VPS23) and VPS28 were originally identified as ESCRT-I components. Using yeast two-hybrid screens, we identified one of a family of human proteins (VPS37C) as a Tsg101-binding protein. VPS37C can form a ternary complex with Tsg101 and VPS28 by binding to a domain situated toward the carboxyl terminus of Tsg101 and binds to another class E VPS factor, namely Hrs. In addition, VPS37C is recruited to aberrant endosomes induced by overexpression of Tsg101, Hrs, or dominant negative form of the class E VPS ATPase, VPS4. Enveloped viruses that encode PTAP motifs to facilitate budding exploit ESCRT-I as an interface with the class E VPS pathway, and accordingly, VPS37C is recruited to the plasma membrane along with Tsg101 by human immunodeficiency virus, type 1 (HIV-1) Gag. Moreover, direct fusion of VPS37C to HIV-1 Gag obviates the requirement for a PTAP motif to induce virion release. Depletion of VPS37C from cells does not inhibit murine leukemia virus budding, which is not mediated by ESCRT-I, however, if murine leukemia virus budding is engineered to be ESCRT-I-dependent, then it is inhibited by VPS37C depletion, and this inhibition is accentuated if VPS37B is simultaneously depleted. Thus, this study identifies VPS37C as a functional component of mammalian ESCRT-I.     

A decade of <Emphasis Type="Italic">Bt</Emphasis> cotton in Chinese fields: Assessing the direct effects and indirect externalities of Bt cotton adoption in China

The objective of this study is to examine whether or not the gains from reduced spraying for bollworms are being sustained more than one decade after the initial adoption in 2007. Based on farm-level data collected by the authors in 1999–2007 in 16 villages from 4 provinces, this study shows that insecticides applied for controlling bollworms have declined. This analysis supports Chinese policy makers’ decision to not require refuges of non-Bt cotton fields. It also suggests that past studies may have underestimated the benefits from adopting Bt technology.     

Microtubule-associated serine/threonine kinase-205 kDa and Fc gamma receptor control IL-12 p40 synthesis and NF-kappa B activation

Stimulation of murine macrophages with LPS results in the coordinated activation of a set of proinflammatory cytokines and costimulatory molecules, including TNF-alpha, IL-6, IL-1, IL-8, IL-12, and CD80. Macrophage LPS-induced synthesis of IL-12 is inhibited following FcgammaR ligation; TNF-alpha secretion is unchanged. We report that microtubule-associated serine/threonine kinase-205 kDa (MAST205) is required for LPS-induced IL-12 synthesis. RNA interference-mediated suppression of MAST205 results in the inhibition of LPS-stimulated IL-12 promoter activity and IL-12 secretion, from both J774 cells and bone marrow-derived macrophages. Similarly, dominant-negative MAST205 mutants inhibit LPS-stimulated IL-12 synthesis and NF-kappaB activation, but do not affect IL-1 or TNF-alpha signaling. Finally, macrophage FcgammaR ligation regulates MAST205 by inducing the rapid ubiquitination and proteasomal degradation of the protein.     

Induced ovulation and egg deposition in the direct developing anuran <Emphasis Type="Italic">Eleutherodactylus coqui</Emphasis>

This study investigates ovulation and egg deposition behaviors in the anuran Eleutherodactylus coqui from Puerto Rico in response to stimulation with gonadotropin and gonadotropin releasing hormones. Five hormones were tested by injection over a range of doses, including mammalian LHRH, avian LHRH, fish LHRH, D-Ala6, des-Gly10 ethylamide LHRH and hCG. We report a low level of ovulation and egg deposition in response to all hormones, with the most complete and consistent results from the non-natural D-Ala6, des-Gly10 ethylamide LHRH derivative. To confirm the viability of eggs produced in this manner we performed in vitro fertilization experiments that resulted in the development of normal frogs. Reproductive behaviors in E. coqui are apparently not controlled by a mammalian form of LHRH as reported in other common laboratory anuran species. D-Ala6, des-Gly10 ethylamide LHRH induces ovulation and deposition of mature and fertilizable eggs in E. coqui.     

Evidence of a Male Sex Pheromone in the Round Goby (Neogobius melanostomus)

The reproductive success of the round goby (Neogobius melanostomus), an invasive fish, may be mediated by the use of pheromones. We hypothesized that reproductive male (RM) round gobies release sex pheromone to which reproductive females (RF) respond. In this study, we compared behavioural and electrophysiological responses of reproductive and non-reproductive female round gobies to conspeci fic males. Results of behavioural experiments in the laboratory showed that RF spent significantly more time near the source of the male odour compared with odours from control water. However, RF did not distinguish between odours from non-reproductive male (non-RM) water and control water. Non-reproductive females (non-RF) were not attracted to odours released from RM or non-RM water. Results of electro-olfactogram (EOG) responses showed that both RF and non-RF discriminated between HPLC fractionated RM and non-RM odours. However, the EOG responses of RF were about eight-fold higher than non-RF exposed to RM odours. These findings confirm that RM round gobies release a pheromone signal that attracts RF. The results of this research may be useful in developing control strategy using natural pheromones to disrupt the reproductive behaviour of the invasive round goby and to curtail its effects on native species. An erratum to this article is available at .     

Effects of turbulence on the feeding rate of a pelagic predator: The planktonic hydroid Clytia gracilis

Relatively little is known about the role of turbulence in a predator-prey system where the predator is a passive, pelagic forager. The Campanulariid hydroid Clytia gracilis (Cnidaria, Hydrozoa) is unusual because it occurs as planktonic colonies and is reported to forage passively in the water column on Georges Bank, Massachusetts, USA. In this study, we investigated the role of various turbulence conditions on the feeding rate of C. gracilis colonies in laboratory experiments. We found a positive relationship between turbulence velocities and feeding rates up to a turbulent energy dissipation rate of ca. 1 cm² s^− 3. Beyond this threshold feeding rate decreased slightly, indicating a dome-shaped relationship. Additionally, a negative relationship was found between feeding efficiency and hydroid colony size under lower turbulent velocities, but this trend was not significant under higher turbulence regimes.