Rank-related maternal effects of androgens on behaviour in wild spotted hyaenas

Within any hierarchical society, an individual's social rank can have profound effects on its health and reproductive success, and rank-related variation in these traits is often mediated by variation in endocrine function. Maternal effects mediated by prenatal hormone exposure are potentially important for non-genetic inheritance of phenotypic traits related to social rank, and thus for shaping individual variation in behaviour and social structure. Here we show that androgen concentrations in wild female spotted hyaenas (Crocuta crocuta) are higher during late gestation in dominant females than in subordinate females. Furthermore, both male and female cubs born to mothers with high concentrations of androgens in late pregnancy exhibit higher rates of aggression and mounting behaviour than cubs born to mothers with lower androgen concentrations. Both behaviours are strongly affected in other mammals by organizational effects of androgens, and both have important effects on fitness in hyaenas. Therefore, our results suggest that rank-related maternal effects of prenatal androgen exposure can adaptively influence offspring phenotype in mammals, as has previously been shown to occur in birds. They also suggest an organizational mechanism for the development of female dominance and aggressiveness in spotted hyaenas, traits that may offset the costs of extreme virilization.     

Somatic mosaic IDH1 and IDH2 mutations are associated with enchondroma and spindle cell hemangioma in Ollier disease and Maffucci syndrome

Ollier disease and Maffucci syndrome are non-hereditary skeletal disorders characterized by multiple enchondromas (Ollier disease) combined with spindle cell hemangiomas (Maffucci syndrome). We report somatic heterozygous mutations in IDH1 (c.394C>T encoding an R132C substitution and c.395G>A encoding an R132H substitution) or IDH2 (c.516G>C encoding R172S) in 87% of enchondromas (benign cartilage tumors) and in 70% of spindle cell hemangiomas (benign vascular lesions). In total, 35 of 43 (81%) subjects with Ollier disease and 10 of 13 (77%) with Maffucci syndrome carried IDH1 (98%) or IDH2 (2%) mutations in their tumors. Fourteen of 16 subjects had identical mutations in separate lesions. Immunohistochemistry to detect mutant IDH1 R132H protein suggested intraneoplastic and somatic mosaicism. IDH1 mutations in cartilage tumors were associated with hypermethylation and downregulated expression of several genes. Mutations were also found in 40% of solitary central cartilaginous tumors and in four chondrosarcoma cell lines, which will enable functional studies to assess the role of IDH1 and IDH2 mutations in tumor formation.     

HIV in Africa (Communication arising): chemokine-receptor genes and AIDS risk

Schliekelman et al. have provided a model to quantify the speed at which HIV-resistance haplotypes can become enriched in a susceptible population through a delay in the onset of AIDS, permitting greater lifetime reproduction and the selection of AIDS-delaying haplotypes. But we question their conclusion that there could be a rapid evolution of resistance to AIDS onset in some African populations if the current HIV epidemic persists, as this depends on an untested assumption: that variant forms of the chemokine-receptor-5 (CCR5) gene impart selective advantages or disadvantages in Africa that are comparable to those reported for African Americans. Here we test this premise in a large Ugandan population, and find that CCR5 variants are not associated with HIV/AIDS disease risk in Africa--the origin and centre of the current AIDS pandemic. This gene may therefore not be subject to rapid evolutionary change as a result of the HIV epidemic in Africa.     

Explicating formal epistemology: Carnap's legacy as Jeffrey's radical probabilism

Quine's “naturalized epistemology” presents a challenge to Carnapian explication: why try to rationally reconstruct probabilistic concepts instead of just doing psychology? This paper tracks the historical development of Richard C. Jeffrey who, on the one hand, voiced worries similar to Quine's about Carnapian explication but, on the other hand, claims that his own work in formal epistemology—what he calls “radical probabilism”—is somehow continuous with both Carnap's method of explication and logical empiricism. By examining how Jeffrey's claim could possibly be accurate, the paper suggests that Jeffrey's radical probabilism can be seen as a sort of alternative explication project to Carnap's own inductive logic. In so doing, it deflates both Quine's worries about Carnapian explication and so also, by extension, similar worries about formal epistemology.     

Additional records of the spotted bat ( Euderma maculatum ) from California

Additional records of the spotted bat ( Euderma inaculatum ) from Inyo County and Shasta County, California, are reported. The latter record represents the northernmost locale for this species in California.     

Electron-microscopic mapping of the hinge region of myosin

Summary The trypsin-sensitive sites in the labile hinge region of the myosin molecule are located with heightened accuracy (±2 nm) by electron microscopy as lying at 70, 85, 95, and 103 nm from the C-terminus of the rod section of the molecule.I thank Dr.Michael Young for valuable advice and encouragement, Drs.Jerome Gross andRomaine R. Bruns for use of their electron microscope, and Mrs.Muriel H. Blanchard for excellent technical assistance. This work was supported by the American Heart Association, The John A. Hartford Foundation, Inc., and the National Institutes of Health.     

On the mechanism of immunosympathectomy

Summary The effects in vivo and in vitro of the antiserum to mouse nerve growth factor (NGF) are independent of the presence of complement. These results are consistent with the view that the antiserum acts by neutralizing endogenous NGF.Acknowledgments. Financial support from the Whitehall Foundation, New York, The Wellcome Foundation, U.K. (to J.R.C.) and the Science Research Council (Studentship to M.E.) is gratefully acknowledged. We thank Professor J.H. Humphrey, National Institute for Medical, Research, Mill Hill, London, for discussion and determination of plasma C3 levels.     

Development,plasticity and evolution of butterfly eyespot patterns

The developmental and genetic bases for the formation, plasticity and diversity of eyespot patterns in butterflies are examined. Eyespot pattern mutants, regulatory gene expression, and transplants of the eyespot developmental organizer demonstrate that eyespot position, number, size and colour are determined progressively in a developmental pathway largely uncoupled from those regulating other wing-pattern elements and body structures. Species comparisons and selection experiments suggest that the evolution of eyespot patterns can occur rapidly through modulation of different stages of this pathway, and requires only single, or very few, changes in regulatory genes.