Dichogamy, Sex Allocation, and Mating System of Campanula microdonta and C. punctata

Dichogamy and sex allocation in several populations of Campanula microdonta and C. punctata were investigated with regard to their mating systems. Duration of the staminate phase differed among the populations: staminate phase was longer in self-compatible (SC) and largely outcrossing populations than in self-incompatible (SI) and outcrossing populations or in SC and largely inbreeding populations. Duration of the pistillate phase among the populations was less variable than duration of the staminate phase. Male reproductive effort decreased with increase of the estimated selfing rates. Male allocation (weight ratio of androecium to gynoecium or to total flower) may be used as an indicator of the breeding system. Within each population, small flowers allocate proportionately more resources to the androecium than to the gynoecium. Among populations, SC outcrossing populations tend to produce large ovaries, and SC inbreeding populations tend to produce small ovaries.     

Molecular characterization of the virulence gene virA of the Agrobacterium tumefaciens octopine Ti plasmid

The virulence loci play an essential role in tumor formation by Agrobacterium tumefaciens. Induction of vir gene expression by plant signal molecules is solely dependent on the virulence loci virA and virG. This study focused on the virA locus of the octopine type Ti plasmid pTi15955. The nucleic acid sequence of a 5.7-kilobase fragment encompassing virA was determined. Genetic analysis of this region revealed that virA contains one open reading frame coding for a protein of 91 639 daltons. Immunodetection with antibodies raised against a 35-kDa VirA fusion protein produced in E. coli identified the VirA product in wild-type Agrobacterium cells. Moreover, it is shown that the VirA protein is located in the cytoplasmic membrane fraction of Agrobacterium. These data confirm the proposed regulatory function of VirA whereby VirA acts as a membrane sensor protein to identify plant signal molecules in the environment. The proposed sensory function of VirA strikingly resembles the function of the chemotaxis receptor proteins of E. coli.     

Induction of interdigitating reticulum cell-like differentiation in human monocytic leukemia cells by conditioned medium from IL-2-stimulated helper T-cells

Monocytic leukemia (MoL) cells were obtained from the peripheral blood of a patient in whom the leukemic cells infiltrating various lymphoreticular organs exhibited features intermediate between interdigitating reticulum cells (IDC) and ordinary phagocytic macrophages, whereas the leukemic cells in the peripheral blood were essentially monocytic and lacked such features. Peripheral blood CD4+ T-cells were established as an interleukin-2-dependent T-cell line. When the MoL cells were exposed for a few days to conditioned medium from the T-cell line, they extended several dendritic cytoplasmic projections and became intensely positive for HLA-DR antigen, cytoplasmic S-100β protein, and CD1 antigen. Functionally, the conditioned medium significantly down-regulated Fc-mediated and Fc-independent phagocytic activities, and the levels of lysosomal enzymes such as lysozyme and nonspecific esterase in the MoL cells. Moreover, the conditioned medium significantly up-regulated the accessory cell function of the MoL cells as measured by the primary allogenic mixed leukocyte reaction (MLR). Furthermore, the conditioned medium significantly down-regulated the expression of CD14 antigen. Biochemical analysis indicated that the factor responsible for these changes is a protein which is distinct from known human cytokines and whose molecular weight is approximately 31 kDa. These findings suggest that IDC are closely related the monocytic lineage and that helper T-cells play an important role in constructing the microenvironment of T-lymphoid tissues which is necessary for the differentiation and maturation of IDC.     

A minority of 46,XX true hermaphrodites are positive for the Y-DNA sequence including SRY

Summary A total of 30 cases of 46,XX true hermaphroditism was analysed for Y-DNA sequences including the recently cloned gene for male testis-determination SRY. In 3 cases, a portion of the Y chromosome including SRY was present and, in 2 cases, was localised, to Xp22 by in situ hybridisation. Since previous studies have shown that the majority of XX males are generated by an X-Y chromosomal interchange, the Xp22 position of the Yp material suggests that certain cases of hermaphroditism can arise by the same meiotic event. The phenotype in the 3 SRY-positive cases may be caused by X-inactivation resulting in somatic mosaicism of testis-determining factor expression giving rise to both testicular and ovarian tissues. Autosomal or X-linked mutation(s) elsewhere in the sex-determining pathway may explain the phenotype observed in the remaining 27 SRY-negative cases.     

Selective allele loss and interference between cauliflower mosaic virus DNAs

Summary Some cauliflower mosaic virus (CaMV) alleles are selectively lost during growth of the virus in mixedly infected turnip plants. Viral DNA from plants co-inoculated with DNA of the cabbage S isolate and infectious cabbage S DNA with an extra EcoRI restriciion site lacked the extra site. The EcoRI allele was also lost in most plants co-inoculated with a non-infectious mutant of cabbage S DNA while little selective allele loss was observed with two other non-infectious mutant DNAs. Plants co-inoculated with DNAs of closely-related isolates (CM4-184 and W) contained both parental viral DNAs and some DNAs with characteristics of both parents. Interference, scored as a reduced frequency of infection or a delay in symptom appearance relative to plants inoculated with wild-type DNA, occurred when plants were inoculated with wild-type and mutant DNAs covalently attached to one another in partial dimer plasmid DNAs. Similarities in the conditions leading to selective allele loss and those leading to interference suggest that both may have been due to active gene conversion between CaMV DNA molecules.     

Effects of Glyphosate on the Shikimate Pathway and Regulation of Phenylalanine Ammonia-lyase in Cryptomeria and Perilla Cell Suspension Cultures

Treatment of Cryptomeria and Perilla cell suspension cultureswith glyphosate resulted in a marked suppression of the formationof flavans and caffeic acid derivatives, respectively, whileit caused only a slight decline in the cell growth. In contrastwith 3-deoxy-D-arabino-heptulosonate (DAHP) synthase-Mn isozyme,DAHP synthase-Co isozyme from Cryptomeria and Perilla cellswas much more sensitive to inhibition by glyphosate. The additionof 1 to 2 mM glyphosate caused an accumulation of shikimateand quinate and a reduction of L-phenylalanine in both cellcultures. The inhibition of phenylalanine ammonia-lyase (PAL)activity by glyphosate was reversed by exogenously suppliedL-phenylalanine to near the control level. Cycloheximide andactinomycin D nullified the recovery by exogenous L-phenylalanineon PAL activity. L-Phenylalanine itself promoted PAL activityto some extent. No recovery of PAL activity in L--aminooxy-ß-phenylpropionate(L-AOPP)-treated cell cultures could be observed by the additionof L-phenylalanine. Therefore, L-AOPP seems to inhibit the formationof PAL, though it has been considered a competitive inhibitor. ³Present address: Biological Institute, Faculty of Science,Tohoku University, Sendai 980, Japan. (Received October 28, 1985; Accepted March 13, 1986)     

Analysis of apolipoproteins in high density lipoproteins by high performance liquid chromatography

A simple and rapid method for the analysis of apolipoproteins in high density lipoprotein (HDL) by high performance liquid chromatography (HPLC) has been developed (Kinoshita et al. (1983) J. Biochem. 94, 615-617). With this method, using a sodium phosphate buffer containing 0.1% sodium dodecyl sulfate (SDS) as an eluent, apolipoproteins can be analyzed from a very small amount of HDL fraction without delipidation using organic solvents. Separation profiles of apolipoproteins by this method were examined using several techniques. The elution pattern monitored by A280 can give precise quantitative as well as qualitative information about size-distribution of apolipoproteins, except for the apo C group. Moreover, separation of apo E from apo A-I was found to be improved by column elongation.