Genome organization of herpesvirus aotus type 2.

Herpesvirus aotus type 2, a virus commonly found in owl monkeys without overt disease, has a similar genome structure to the oncogenic herpesviruses of nonhuman primates (herpesvirus saimiri, herpesvirus ateles). Virion DNA of herpesvirus aotus type 2 (M-DNA) has an unique 110-kilobase-pair region of low G + C content (40.2%, L-DNA), inserted between stretches of repetitive H-DNA (68.7% G + C, about 41 kilobase pairs per molecule) that are variable in length. A minority of virions contain defective genomes that consist of repetitive H-DNA only. The H-DNA is composed of various types of repeat units that are related in sequence with each other. The two dominant types of repeats (2.3 and 2.7 kilobase pairs) were cloned and compared by restriction enzyme cleavages and partial nucleotide sequencing. They are homologous in at least 1.3 kilobase pairs. The two forms of repeat units are randomly arranged and oriented in tandem. Reassociation kinetics did not allow detection of sequence homologies between H- and L-DNA of herpesvirus aotus type 2 and the respective sequences of oncogenic primate herpesviruses.     

Modification of the gene 5 DNA unwinding protein with ruthenium

A chemical modification of the gene 5 DNA binding protein (G5BP) from bacteriophage fd was investigated using X-ray diffraction and difference Fourier analysis. The crystalline protein was reacted with pentaammineruthenium (III) trichloride, Ru(NH₃)₅Cl₃, a reagent believed specific for histidine residues and useful in NMR and chemical modification studies of proteins. The major ruthenium site was found by difference Fourier analysis to be 4 Å from histidine 64, the only histidine residue in the molecule. A second bipartite site, believed to be a ruthenium-anion pair, appeared to be salt-bridged to glutamic acid 40 and arginine 16. Indications were present in the difference Fourier results to suggest that the loop containing tyrosine 41 had undergone a slight conformational rearrangement to accommodate this interaction.     

Life-cycle and karyology of Branchiura sowerbyi Beddard (Oligochaeta,Tubificidae)

Data on the life-cycle of a population of Branchiura sowerbyi Beddard in a water-lily tank at the Botanical Garden in Padua are reported. The breeding period is from April to July, after which the reproductive system is partially resorbed (August–September) and reformed later in the autumn. The karyology of the species was also studied, and revealed 38 mitotic chromosomes in the gonia, and 19 bivalents in the primary spermatocytes and in the primary oocytes.     

Radioprotective properties of detoxified lipid A from Salmonella minnesota R595

In the past, the toxicity of bacterial lipopolysaccharide (LPS) or its principal bioactive component, lipid A, has detracted from their potential use as radioprotectants. Recently, a relatively nontoxic monophosphoryl Lipid A (LAM) that retains many of the immunobiologic properties of LPS has been isolated from a polysaccharide deficient Re mutant strain of Salmonella minnesota (R595). The ability of the native endotoxic glycolipid (GL) from S. minnesota (R595) as well as diphosphoryl lipid A (LAD) and nontoxic monophosphoryl lipid A (LAM) derived from GL to protect LPS responsive (CD2F1 or C3H/HeN) and nonresponsive (C3H/HeJ) mice from 60Co gamma irradiation has been studied. Administration of GL, LAD, or LAM to CD2F1 or C3H/HeN mice (400 micrograms/kg) 24 h prior to exposure provided significant radioprotection. No protection was afforded to C3H/HeJ mice. Experiments were also conducted to determine the relative abilities of GL, LAD, and LAM to stimulate hematopoiesis as reflected by the endogenous spleen colony (E-CFU) assay. Protection was not correlated with the ability of these substances to increase E-CFUs or to induce colony-stimulating activity (CSA).     

HLA Haplotypes with C4B5; evidence for further allelic heterogeneity

Twenty-three individuals from various disease groups and normal controls were identified by immunofixation with anti-C4, C4-dependent lysis, determination of Rg (Rodgers) and Ch (Chido) phenotypes, and immunoblotting with C4-specific mouse monoclonal antibody. We found that one haplotype predominates with the C4B ^* 5 allele, HLA-A11, B22(55), Cw3, Bf ^* S, C4A ^* 4B ^* 5, which also carries the Ch ^{1,–2, 3} haplotype. The B5 allotype was also found with HLA-1360, HLA-1335 in Caucasoids, and HLA-B18 in non-Caucasoids; these carried the Ch ^{–1, –2, –3} haplotype. Our results are in accord with an earlier report of two B5 subtypes, B5Rg⁺ and B5Rg^– (Roos et al. 1984). The specificity of the mouse monoclonal antibodies IC4 and 21312 had been previously related to C4A and C4B, respectively, but our results suggest that they relate more closely to Rg and Ch determinants.     

Variation in the ribosomal RNA genes among individuals of Vicia faba

Summary Length heterogeneity in the ribosomal repeat of Vicia faba is due to the presence of variable numbers of a 325 bp subrepetitive element within the nontranscribed spacer region. The distribution of size classes among 88 individuals within a population was investigated by blot-hybridization. We find that individual plants can exhibit more than 20 size classes and that hybridization patterns are highly diverse from individual to individual, more so than for any species so far investigated. In contrast, no such differences are observed in patterns for different tissues from a single plant or from parental to F₁ generation. Some changes were observed in the F₂ generation. We conclude that unequal recombination can give rise to the diversity that we observe for the V. faba rDNA repeats.     

Somatic hybrids between Solanum brevidens and Solanum tuberosum: Expression of a late blight resistance gene and potato leaf roll resistance

Hexaploid somatic hybrids resulting from mesophyll protoplast fusions between Solanum brevidens Phil., PI 218228, and Solanum tuberosum L., PI 203900 were tested for late blight resistance using two races of Phytophthora infestans Monte., de Bary. The S. tuberosum parent was a late blight differential possessing the R4 gene which confers resistance to race 0. The S. brevidens parent is resistant to potato leaf roll virus. Inoculations with both compatible (race 1.3.4.5) and incompatible (race 0) races of P. infestans clearly demonstrated the expression of the late blight resistance gene in all of the hybrid progeny tested. Most of the hybrids tested were also resistant to potato leaf roll virus (PLRV), indicating that the S. brevidens genes for PLRV resistance were present and expressed.     

Biosynthesis and distribution of ecdysone and 20-OH-ecdysone in Aedes aegypti

The distribution and biosynthesis of ecdysone and 20-hydroxyecdysone (20-OH-ecdysone) was followed in sugar- and blood-fed female Aedes aegypti. In both sugar- and early blood-fed animals most of the ecdysteroid determined by radioimmunoassay was found outside the ovary. Twenty-four to 40 h after blood feeding, however, ecdysteroid was distributed between ovary and carcass in the ratio of 1:1.5. Ecdysteroid titer reached a plateau between 18 to 40 h after the blood meal and decreased thereafter. Analysis of the ecdysteroid titer using thin layer chromatography (TLC) and high performance liquid chromatography (HPLC) revealed that both 20-OH-ecdysone and ecdysone were synthesized after the blood meal. The ratio of 20-OH-ecdysone to ecdysone remained essentially constant and fluctuated in parallel throughout egg development. Chromatography of the early ecdysteroid peak (8 h after feeding) using TLC and HPLC indicated that although it cross-reacted with ecdysteroid antibodies, it did not have the same elution times as ecdysone and 20-OH-ecdysone and is, therefore, probably a precursor of these ecdysteroids. Injections of egg development neurosecretory hormone (EDNH) preparation purified to near homogeneity, into ligated abdomens, induced ecdysteroid synthesis only if the abdomens were first treated with methoprene (12.5 pg). Methoprene at this concentration did not stimulate ecdysteroid synthesis in these abdomens. When blood-fed females were treated with [4-¹⁴C] cholesterol and analyzed using TLC and HPLC procedures, both [¹⁴C]labeled ecdysone and [¹⁴C]labeled 20-OH-ecdysone were synthesized in the ratio of 1:1.5. This report is the first to show that both ecdysone and 20-OH-ecdysone are synthesized in vivo in female A. aegypti.