Induction of a cellular enzyme for energy metabolism by transforming domains of adenovirus E1a.

Brain creatine kinase is a major enzyme of cellular energy metabolism. It is overexpressed in a wide range of tumor cell lines and is used as a tumor marker. We reported recently that the promoter of the human gene has a strong sequence similarity to the adenovirus E2E promoter. This similarity suggested that the brain creatine kinase gene may be regulated by the viral activator E1a. Experiments reported here showed that both enzyme activity and mRNA levels were induced by the oncogenic products of the E1a region of adenovirus type 5, but unlike the viral E2E promoter, which is induced predominantly by E1a domain 3, brain creatine kinase induction required domains 1 and 2. These domains are important for transformation and for the association of E1a with the retinoblastoma gene product and other cellular proteins. The induction by an oncogene of a cellular gene for energy metabolism may be of significance for the metabolic events that take place after oncogenic activation.     

Allozyme diversity and introgression in the Galapagos Islands endemic Gossypium darwinii and its relationship to continental G. barbadense

Gossypium darwiniiWatt is a tetraploid cotton endemic to the Galapagos Islands. Opinion has been divided as to whether or not it deserves recognition at the specific rank, with some considering it a variety of its presumed progenitor, the widely distributed South American species G. barbadense L. A previous hypothesis states that much of the perceived intergradation between the two taxa arose as a consequence of introgression from G. barbadense following its introduction to the archipelago during the past several hundred years. We performed allozyme analysis on 58 accessions of G. darwinii from six islands, using 17 enzymes collectively encoded by 59 loci. Levels of variation were high for an island endemic, with a mean number of alleles per locus of 1.34 and an average panmictic heterozygosity of 0.062. Principal component analysis revealed clustering of accessions according to their island of origin, and a spatial pattern of island-clusters that approximates geographical relationships among islands. Genetic relationships of G. darwinii with G. barbadense and G. hirsutum L. were studied using previously generated allozyme data. Significant introgression of G. hirsutum alleles was detected; however morphological considerations support the hypothesis that much of G. darwinii's diversity stems from interspecific gene flow from G. barbadense, Evidence is presented suggesting that the occurrence of G. hirsutum alleles in G. darwinii derives not from direct hybridization, but from a mediated transfer through introduced, G. hirsutum-introgressed; G. barbadense. Gossypium darwinii and G. barbadense are nearly fixed for different alleles at four loci and each contains a large number of unique alleles. Notwithstanding the high interspecific Nei's genetic identity (0.949), the allozyme data support geographical and morphological evidence in suggesting that a specific rank for G. darwinii is warranted.     

Regulation of human T cell leukemia virus expression

Retroviruses of the type C morphology have been implicated in a wide variety of diseases in animals and humans. The human T cell leukemia viruses types I (HTLV-I) and II (HTLV-II), the prototypic human-type C retroviruses, have been identified as the causative agents of some forms of human leukemia and neurological disorders. The genetic structure and regulation of the HTLVs are more complex than their avian and murine leukemia virus counterparts. In addition to the gag, pol, and env genes that encode the characteristic virion proteins of all replication competent retroviruses, the genomes of HTLV encode the non-structural proteins, Tax and Rex, which are required for regulating viral gene expression. To understand what appears to be a complex mechanism of disease induction by HTLV, elucidating the regulation and function of the viral gene products and the interaction of these products with each other, as well as with cellular factors, will be critical. This review focuses primarily on regulation of HTLV gene expression in the infected human T lymphocyte, but also discusses analogous gene regulation by the human immunodeficiency virus (HIV). It concentrates specifically on the role these gene products play in virus replication and, ultimately, pathogenesis.     

Ritual production of environmental history among the Arawakan Wakuénai of Venezuela

This essay examines ritual and ceremonial activities among the Arawakspeaking Wakuénai of the Venezuelan Amazon as processes of constructing power relations in changing historical and ecological conditions. Ritual evocations of the vertical dimension of power relations between mythic ancestors and human descendants adapt local populations to conditions of relatively severe stress, such as epidemics and scarcity of fish in long wet seasons. Other rituals evoke the horizontal dimension of power relations between affinally-related groups as a way of expanding the local descent group in conditions of lowered stress. These two ways of exercising ritual power link human populations to specific natural habitats and provide flexibility needed to adjust to demographic and other historical changes. Through ritual performances, the Wakuénai transform the natural environment into a cultural landscape of socialized objects and, conversely, remember the history of political relations among peoples through spirit-naming of natural species, objects, places, and geographic landmarks.     

The effect of erythrocyte associated light scattering on membrane fluorescence polarization

Summary The apparent membrane fluorescence anisotropy of 1,6-diphenyl-1,3,5-hexatriene has been reported to be lower in intact erythrocytes than in isolated erythrocyte membranes. Although this difference was once suggested to be caused by the fluidizing effect associated with the loss of erythrocyte proteins during membrane isolation, it is currently thought to be an artifact resulting from intense light scattering properties of intact erythrocytes which overwhelm extrapolation methods of correcting for light scattering. This study confirmed that, at erythrocyte concentrations greater than 10⁷ cells/ml, this difference was caused by intense light scattering; however, at erythrocyte concentrations less than 4.0 × 10⁶ cells/ml, the anisotropy values for erythrocytes and isolated membranes are identical, demonstrating that intense light scattering can be overcome with dilute suspensions of cells.