Biologic and molecular characterization of two newly isolated ras-containing murine leukemia viruses.

A murine sarcoma virus (MSV) was recovered from an (NFS X NS.C58v-1) F1 mouse which developed splenic sarcoma and erythroleukemia 6 months after inoculation with a mink cell focus-inducing murine leukemia virus (MuLV) isolated from an NFS mouse infected with a wild mouse ecotropic MuLV. The MSV, designated NS.C58 MSV-1, induced foci of transformation in mouse and rat fibroblasts, and inoculation of mice of various strains 2 weeks of age or younger resulted in erythroleukemia and sarcomatous lesions in spleen, lymph node, and brain. The MSV provirus was molecularly cloned from a genomic library prepared from transformed non-producer rat cells. The 8.8-kilobase proviral DNA contained a 1.0-kilobase p21 ras coding segment which replaced most of the gp70-encoding portion of an MuLV, most likely the endogenous C58v-1 ecotropic virus. The ras oncogene is closely related to v-Ha-ras by hybridization, expression of p21 protein, and nucleotide sequence. It is nearly identical in sequence to v-bas, the only previously described transduced, activated mouse c-ras. At position 12 in the p21 coding region, arginine is substituted for the naturally occurring glycine present in c-ras. A second MSV isolate is described which is similar to NS.C58 MSV-1 except for a 100- to 200-base-pair deletion in the noncoding region of the ras-containing insert.     

Isolation and characterization of quinoline-degrading bacteria from subsurface sediments.

Two gram-negative, motile bacteria isolated from deep subsurface sediments mineralized the nitrogen-containing polyaromatic hydrocarbon quinoline under aerobic conditions and transformed quinoline to soluble intermediates under anaerobic conditions. Many aromatic compounds were also able to serve as the sole source of carbon and energy under aerobic conditions. Rapid aerobic mineralization of quinoline at concentrations as low as 0.002 microgram ml-1 indicates that these organisms possess a high-affinity uptake and utilization system, which may reflect the oligotrophic nature of deep subsurface environments. Both bacteria harbored four plasmids of identical size, ranging from 50 to 440 kilobases.     

Effects of non-MHC loci on resistance to retrovirus-induced immunodeficiency in mice

Mice of certain strains are highly sensitive to development of a severe immunodeficiency disease following inoculation as adults with LP-BM5 murine leukemia viruses (MuLV) whereas others are extremely resistant. These strain-dependent differences in response to infection have been shown to be genetically determined with resistance to disease being, in general, associated with homozygosity for Fv-1 ⁿand H-2 haplotypes a and d and sensitivity with homozygosity for Fv-1 ^band other H-2 haplotypes including b, s, and q. The Fv-1 ^b, H-2 ^rstrain RIIIS/J (RIIIS) was found to be highly resistant to disease even though B10.RIII(71NS)/J (B10.RIII), also H-2 ^r, was very sensitive, thus excluding a role for H-2 in the resistance of RIIIS. The characteristics of RIIIS resistance were evaluated in studies of infected (B10.RIII×RIIIS) F₁, F₂ and reciprocal backcross mice. Resistance to disease was shown to be semidominant and determined by more than one gene, although a preponderant influence of a single gene was suggested. Studies of segregating populations showed that resistance was not associated with or linked to polymorphisms of the V _\complex or genes in proximity to the Emv-2 locus on chromosome 8. However, there was almost complete concordance between absence of disease in infected mice and inhibition of ecotropic virus spread. These results demonstrate that genes other than Fv-1 or H-2 can profoundly influence the development of retrovirus-induced immunodeficiency and replication of ecotropic viruses.Abbreviations MuLV murine leukemia virus - MCF mink cell focus-inducing MuLV - B6 C57BL/6 - BM5d the defective virus in LP-BM5 MuLV - MAIDS murine acquired immunodeficiency syndrome - RIIIS RIIIS/J - B10.RIII B10.RIII (71NS)/J - MLR mixed lymphocyte reaction - FACS fluorescence activated cell sorter     

Susceptibility to raf and raf/myc retroviruses is governed by different genetic loci.

The susceptibility to tumors induced by raf and raf/myc retroviruses was investigated in BALB/c, C57BL/6, (BALB/c x C57BL/6)F1 and (BALB/c x C57BL/6) backcross mice. Newborn mice were susceptible to neoplasms generated by both viruses, but resistance to raf-induced leukemia developed rapidly in all mice as they matured. Older C57BL/6 mice were also resistant to raf/myc lymphomas, whereas BALB/c mice remained susceptible to the virus at all ages, indicating that different genes control susceptibility to raf and raf/myc tumors. From these data and the susceptibility of C x B recombinant inbred strains, it appears that very few genes (perhaps even a single gene) may govern susceptibility to raf/myc lymphomas and that resistance is the dominant trait.     

Complex polar lipids of a hot spring cyanobacterial mat and its cultivated inhabitants.

The complex polar lipids of the hot spring cyanobacterial mat in the 50 to 55 degrees C region of Octopus Spring, Yellowstone National Park, and of thermophilic bacteria cultivated from this or similar habitats, were compared in an attempt to understand the microbial sources of the major lipid biomarkers in this community. Intact complex lipids were analyzed directly by fast atom bombardment mass spectrometry (FAB-MS), two-dimensional thin-layer chromatography (TLC), and combined TLC-FAB-MS. FAB-MS and TLC gave qualitatively similar results, suggesting that the mat contains major lipids most like those of the cyanobacterial isolate we studied, Synechococcus sp. strain Y-7c-s. These include monoglycosyl, diglycosyl, and sulfoquinosovyl diglycerides (MG, DG, and SQ, respectively) and phosphatidyl glycerol (PG). Though Chloroflexus aurantiacus also contains MG, DG, and PG, the fatty acid chain lengths of mat MGs, DGs, and PGs resemble more those of cyanobacterial than green nonsulfur bacterial lipids. FAB-MS spectra of the lipids of nonphototrophic bacterial isolates were distinctively different from those of the mat and phototrophic isolates. The lipids of these nonphototrophic isolates were not detected in the mat, but most could be detected when added to mat samples. The mat also contains major glycolipids and aminophospholipids of unknown structure and origin. FAB-MS and TLC did not always give quantitatively similar results. In particular, PG and SQ may give disproportionately high FAB-MS responses.     

Seed transmission of turnip yellow mosaic virus in winter turnip and winter oilseed rapes

This is the first record of seed transmission of turnip yellow mosaic virus (TYMV) in oilseed and turnip rapes. The seed transmission of TYMV in a naturally infected winter turnip rape (Brassica napus var. silvestris) cultivar Perko PVH was investigated. By ELISA 1.6%, 3.2% and 8.3% seed transmission of the virus was found in seed of plants from three localities. The proportion of infected seeds produced by artificially infected plants of winter oilseed rape (Brassica napus ssp. oleifera) and winter turnip rape cultivars was determined. The virus transmission rate, expressed as the proportion of virus-infected plants which germinated from the seed was for the oilseed rape cvs Jet Neuf 0.1%, Solida 0.4%, Silesia 0.8%, Darmor 1.2%, SL-507 0.2%, SL-509 0.0% and for the winter turnip rape cv. Perko 1.5%. ELISA cannot be used in direct tests on bulk seed lots to estimate proportion of infected seed, but must be used on germinated seedlings.     

Aspects of hadrosaurian cranial anatomy

Supraorbital bones in Saurolophus angustirostris are described, and their presence in all hadrosaurs is suggested. Frontal-nasal and premaxillar-nasal fontanellae are distinguished in hadrosaurs; their presence is explained as connected with growth and considered to he responsible for the variability of crest structures. New data indicating the presence of a cartilaginous diverticulum nasi within the circumnarial depression in Saurobphus ongustirostris are presented. A physiological (respiratory and/or thermoregulatory) function of the nasal diverticulum is proposed.