PHYLOGENETIC AFFINITIES OF THE SARCINOCHRYSIDALES AND CHRYSOMERIDALES (HETEROKONTA) BASED ON ANALYSES OF MOLECULAR AND COMBINED DATA1

Small-subunit ribosomal RNA nucleotide sequences were inferred for Giraudyopsis stellifera Dangeard (Chrysomeridales), as well as for Pulvinaria sp. and Sarcinochrysis marina Geitler (Sarcinochrysidales,). Phylogenetic analyses of the molecular data indicate that the former is weakly related to the Phaeophyceae/Xanthophyceae clade, whereas the latter two have affinities to the Pelagophyceae, and the Sarcinochrysidales sensu stricto is transferred to this class. A recent study proposed that the Pelagophyceae belongs to a larger assemblage of chromophytic species characterized by reduced flagellar apparatuses. Although the flagellar apparatus characterizing the Sarcinochrysidales is reduced relative to the Chysomeridaels and some other chromophytes, it is the most complicated to be associated with “the reduced flagellar apparatus” lineage. Cladistic analyses of a traditional data set (largely ultrastructural features of the flagellar apparatus) and a combined traditional/molecular data set were used to assess the evolutionary trends of reduction in the flagellar apparatus within the heterokont chromophytes.     

Physical map of the bacteriophage L (Salmonella typhimurium)

Abstract A circular restriction map of the genome of the phage L ( Salmonella typhimurium ) has been constructed with five restriction endonucleases, Eca I, Eco RI, Bam HI, Bgl I, and Pst I. The Eco RI fragments of phage-L DNA were cloned into pACYC184, and the resulting recombinant plasmids pL1, pL2,…,pL7 were introduced into Salmonella typhimurium . The genes present on the fragments cloned were identified by the marker rescue experiments with the L-phage amber mutants. A physical gene map of the L genome obtained in this way was compared with that of P22.     

Production of antisera against contraceptive steroids

A four step synthesis of 6-(O-carboxymethyl)oximinoethynylestradiol is reported. This compound, 6-(O-carboxymethyl)oximinomestranol, the 3-(O-carboxymethyl)oximes of norethindrone and norgestrel and the 3-hemisuccinate of ethynylestradiol were synthesized and conjugated with bovine serum albumin. Rabbits were immunized at 3 dose levels of haptene (20, 66 and 200 nmoles) and eight weeks later with a booster containing 66 nmoles of haptene. The antibody titer and association constant of responding rabbits was nearly independent of dose although most antibody production occurred after the booster injection. Antibodies to mestranol crossreacted more than 100% with ethynylestradiol and to a small extent with norethindrone and norgestrel.     

Evaluation of adrenal function in rats by the measurement of urinary free corticosterone, free aldosterone and free 11-deoxycorticosterone.

Methods für the determination of urinary free corticosterone, free aldosterone and free 11-deoxycorticosterone (DOC) in rats are described. The free corticosteroids were measured in urine samples of 0.1–0.5 (2.0) ml by radioimmunoassay after purification by column chromatography. The validity of the methods is demonstrated by the data of the free urinary corticoids under basal conditions and after adrenal suppression and various forms of adrenal stimulation. The basal excretion of free corticosterone, free aldosterone and free DOC was 123.71 ± 15.31 (x? ± SD), 3.87 ± 1.29 and 10.61 ± 2.24 ng/day, respectively, exhibiting a decrease to 26.20 ± 5.21, 1.05 ± 0.47 and 1.35 ± 1.20 ng/day after adrenal suppression by dexamethasone. Irrespective of the mode of adrenal stimulation i.e., synthetic ACTH and systemic (cold, hunger) or neurotrophic (ether, reserpine) stress stimuli free corticosterone increased to about 450 ng/day, while free aldosterone excretion decreased during hunger and cold and was strongly enhanced after the application of reserpine. Furthermore, determination of urinary free DOC, which increased by a factor of 4, may be applied in the metyrapone test. There was a good correlation between the excretion of free corticosterone and that of free aldosterone and free DOC under basal conditions and after ACTH application, demonstrating that ACTH is responsible for the secretion of all the 3 corticoids measured. It is concluded, that the measurement of the urinary excretion of corticosterone, aldosterone and DOC is a valuable parameter of adrenal function in rats. Furthermore, in small laboratory animals like rats steroid measurements in urine are often more advantageous than Measurements in plasma.     

Correlations between the thermal stability of chloroplast (thylakoid) membranes and the composition and fluidity of their polar lipids upon acclimation of the higher plant,Nerium oleander,to growth temperature

The thermal stability of excitation transfer from pigment proteins to the Photosystem II reaction center of Nerium oleander adjusts by 10 Celsius degrees when cloned plants grown at 20°C/15°C, day/night growth temperatures are shifted to 45°C/32°C growth temperature or vice versa. Concomitant with this adjustment is a decrease in the fluidity of thylakoid membrane polar lipids as determined by spin labeling. The results are consistent with the hypothesis that there is a limiting maximum fluidity compatible with maintenance of native membrane structure and function. This limiting fluidity was about the same as for a number of other species which exhibit a range of thermal stabilities. Inversely correlated shifts in lipid fluidity and thermal stability occurred during the time course of acclimation of N. oleander to new growth temperatures. Thus, the temperature at which the limiting fluidity was reached changed during acclimation while the limiting fluidity remained constant. Although the relative proportion of the major classes of membrane polar lipids remained constant during adjustments in fluidity, large changes occured in the abundance of specific fatty acids. These changes were different for the phospho- and galacto-lipids suggesting that the fatty acid composition of these two lipid classes is regulated by different mechanisms. Comparisons between membrane lipid fluidity and fatty acid composition indicate that fluidity is not a simple linear function of fatty acid composition.     

Zinc finger motif for single-stranded nucleic acids? investigations by nuclear magnetic resonance

Nuclear magnetic resonance (NMR) methods have been used to address issues regarding the relevance and feasibility of zinc binding to "zinc finger-like" sequences of the type C-X2-C-X4-H-X4-C [referred to as CCHC or retroviral-type (RT) zinc finger sequences]. One-dimensional (1D) NMR experiments with an 18-residue synthetic peptide containing the amino acid sequence of an HIV-1 RT-zinc finger domain (HIV1-F1) indicate that the sequences are capable of binding zinc tightly and stoichiometrically. 1H-113Cd spin echo difference NMR data confirm that the Cys and His amino acids are coordinated to metal in the 113Cd adduct. The 3D structure of the zinc adduct [Zn(HIV1-F1)] was determined to high atomic resolution by a new NMR-based approach that utilizes 2D-NOESY back-calculations as a measure of the consistency between the structures and the experimental data. Several interesting structural features were observed, including (1) the presence of extensive internal hydrogen bonding, and (2) the similarity of the folding of the first six residues to the folding observed by X-ray crystallography for related residues in the iron domain of rubredoxin. Structural constraints associated with conservatively substituted glycines provide further rationale for the physiological relevance of the zinc adduct. Similar NMR and structural results have been obtained for the second HIV-1 RT-zinc finger peptide, Zn(HIV1-F2). NMR studies of the zinc adduct with the NCP isolated directly from HIV-1 particles provide solid evidence that zinc finger domains are formed that are conformationally similar (if not identical) to the peptide structures.(ABSTRACT TRUNCATED AT 250 WORDS)     

Two new subspecies of Bacillus thuringiensis isolated in Japan: Bacillus thuringiensis subsp. kumamotoensis (serotype 18) and Bacillus thuringiensis subsp. tochigiensis (serotype 19)

Bacteriological and serological characteristics of three Bacillus thuringiensis isolates obtained in Japan were investigated. They formed typical rhomboidal parasporal inclusions but flagellar (H) antigens of these isolates were different from those of the known 17 H serotypes of B. thuringiensis. The three isolates were divided into two new serotypes (serotypes 18 and 19). The serotype 18 isolate (3–71) produced thermostable exotoxin and the inclusions of this isolate were toxic to larvae of the silkworm, Bombyx mori, but nontoxic to larvae of the mosquito, Aedes aegypti. The other isolate (119-72) belonging to serotype 18 produced inclusions nontoxic to larvae of B. mori and A. aegypti and did not produce thermostable exotoxin. However, other bacteriological properties of the isolate 119-72 were similar to those of the isolate 3–71. The serotype 19 isolate (117-72) produced inclusions nontoxic to larvae of B. mori and A. aegypti and did not produce thermostable exotoxin. Acid production from saccharose and the production of brownish purple pigment were observed in the two serotype 18 isolates, while neither of them was observed in the serotype 19 isolate. In other 29 biochemical properties tested, there was no difference among the three isolates. Based on these characteristics, the following two subspecies names are proposed: Bacillus thuringiensis subsp. kumamotoensis (serotype 18) for the type strain 3–71 and Bacillus thuringiensis subsp. tochigiensis (serotype 19) for the type strain 117-72.     

Assignment of the gene for dipeptidase 2 to Mus musculus chromosome 18 by somatic cell hybridization

Evidence is presented for the assignment of the gene for dipeptidase 2 to Mus musculus chromosome 18 by synteny testing and karyotypic analysis of Chinese hamster × mouse somatic cell hybrid clones. DIP-2 and chromosome 18 were expressed concordantly in 24/24 clones examined (ten primary clones and 14 secondary clones). Synteny testing indicated that DIP-2 was not expressed concordantly with the expression of any marker enzymes.This work was supported by NIH grant USPHS GM 09966.     

Biotransformation of pregnenolone - 7alpha-3H, progesterone - 7alpha-3H and dehydroepiandrosterone - 7alpha-3H by porcine fetal and maternal adrenal homogenate preparations.

The biotransformation of pregnenolone-7alpha-3H and of progesterone-7alpha-3H by porcine fetal and maternal adrenal homogenates at 56 and 112 days of pregnancy and of dehydroepiandrosterone-7alpha-3H by fetal adrenal homogenates has been investigated in vitro. Both pregnenolone-7alpha-3H and progesterone-7alpha-3H were metabolized extensively by maternal adrenal preparations, the principal radioactive metabolites isolated being cortisol, corticosterone, 11-deoxycortisol, deoxycorticosterone, 11beta-hydroxyprogesterone and androstenedione. In addition, 17alpha-hydroxyprogesterone, 20alpha-dihydroprogesterone and cortisone were formed from both substrates and 17alpha-hydroxypregnenolone and progesterone were formed from pregnenolone. Although essentially the same radioactive metabolites were isolated after incubation of fetal adrenal glands with pregnenolone-7alpha-3H or progesterone-7alpha-3H, a greater proportion of the radioactivity was associated with corticosteroids at 112 days of pregnancy than at 56 days. 11beta-Hydroxyandrostenedione and androstenedione were isolated and identified together with an unknown polar metabolite, after incubation of fetal adrenal tissue with dehydroepiandrosterone-7alpha-3H. These results are discussed in relation to feto-placental steroid biosynthesis and metabolism and the role of the fetal adrenal in the initiation of parturition in the pig.