Normal p21N-ras couples bombesin and other growth factor receptors to inositol phosphate production

Many receptors, in response to ligand activation, trigger inositol phospholipid breakdown, which leads to rapid intracellular responses. The sustained activation of this pathway is believed to be at least one of the factors involved in the stimulation of cell growth and there has been much speculation that certain oncogenes use this pathway to effect uncontrolled cellular proliferation. It has been suggested, by analogy with the receptor-mediated control of adenylate cyclase, that the receptor stimulation of inositol phospholipid metabolism is mediated through a guanine nucleotide regulatory protein (G-protein) called Gp (or Np). Although such a species has not been identified, there is now strong experimental evidence that this process is mediated by a G-protein distinct from the stimulatory and inhibitory G-proteins (Gs and Gi, respectively). The ras genes code for a plasma membrane protein, p21, whose only known biochemical property is a high-affinity GTPase activity. We show here that the expression of normal p21N-ras in NIH 3T3 fibroblasts leads to the coupling of certain growth factor receptors to stimulated inositol phosphate production. We propose that the N-ras proto-oncogene encodes a protein which couples the receptors for certain growth factors to the stimulation of phospholipase C. Thus, N-ras p21 may be the putative Gp or a functionally related protein.     

Gamma-interferon is one of several direct B cell-maturing lymphokines

Two classes of molecules often released after the interaction of T lymphocytes, macrophages and antigen are B-cell maturation factors (BMF)1-3 and immune (gamma) interferon (IFN-gamma)4-7. BMFs directly induce the maturation of resting B lymphocytes to the state of active immunoglobulin secretion, while IFN-gamma is defined by the reduction of viral infectivity in vitro. However, interferons have been shown to have a variety of effects and they have also been reported both to increase and decrease B-cell differentiation in intact animals and complex cellular mixtures in vitro. Here we show that murine IFN-gamma produced by recombinant DNA technology shows similar biological effects to BMFs from two other sources. All three preparations induce immunoglobulin secretion by both normal resting murine splenic B cells and the comparable B-cell tumour line WEHI-279.1 (refs 1, 3). IFN-gamma and the other two BMFs are not identical, however, as anti-IFN-gamma antibodies block the effects on B cells of IFN-gamma, but not those of the other two lymphokines. IFN-gamma may be one of several molecules with a direct role in driving the maturation of resting B cells to active immunoglobulin secretion.     

Carnosine levels in blood

Summary Carnosine levels were determined in chick erythrocytes (2510 nmoles/g cells) and plasma from chick (27 nmoles/ml), rat and rabbit. Carnosine was also measured in rabbit reticulocyte-rich blood (105 nmoles/g cells), normal blood (18 nmoles/g cells) and in bone marrow.This work was supported by grant NS-06137 of the National Institutes of Health.     

Genome analysis of the platypus reveals unique signatures of evolution

We present a draft genome sequence of the platypus, Ornithorhynchus anatinus. This monotreme exhibits a fascinating combination of reptilian and mammalian characters. For example, platypuses have a coat of fur adapted to an aquatic lifestyle; platypus females lactate, yet lay eggs; and males are equipped with venom similar to that of reptiles. Analysis of the first monotreme genome aligned these features with genetic innovations. We find that reptile and platypus venom proteins have been co-opted independently from the same gene families; milk protein genes are conserved despite platypuses laying eggs; and immune gene family expansions are directly related to platypus biology. Expansions of protein, non-protein-coding RNA and microRNA families, as well as repeat elements, are identified. Sequencing of this genome now provides a valuable resource for deep mammalian comparative analyses, as well as for monotreme biology and conservation.     

Aquatic insects in the forest canopy: a new genus of moth flies (Diptera: Psychodidae) developing in slime on aerial roots

Many hemiepiphytic plants secrete a thick layer of mucilage to limit desiccation and protect against fungal pathogens. With its stable moisture and protected location, this mucilage constitutes a potentially attractive microhabitat for small animals; however, until now, no animal species have been recorded from it. Larvae of a psychodid fly were collected from the mucilage of a hemiepiphytic Araceae in Braulio Carillo National Park, Costa Rica. Rearing of the larvae yielded specimens of pupae and one adult male described here as Mucomyia emersa Kvifte and Curler gen. nov. sp. nov. An additional species from Costa Rica, Mucomyia browni Kvifte sp. nov., is described based on adult males from the Zurquí de Moravia forest reserve. Mucomyia belongs to tribe Psychodini, which comprises both habitat generalists and specialists. The new species are morphologically similar to those in Philosepedon s. str. and Eurygarka, both of which are known to develop in snail carrion. It is premature to speculate about whether or not species in the new genus are restricted to hemiepiphyte mucilage.

http://www.zoobank.org/urn:lsid:zoobank.org:pub:37CD136B-53D8-4D3E-A34A-3BE4859045E5