Evolution of green lacewings (Neuroptera: Chrysopidae): a molecular supermatrix approach

We present a time‐calibrated phylogeny of the charismatic green lacewings (Neuroptera: Chrysopidae). Previous phylogenetic studies on the family using DNA sequences have suffered from sparse taxon sampling and/or limited amounts of data. Here we combine all available previously published DNA sequence data and add to it new DNA sequences generated for this study. We analysed these data in a supermatrix using Bayesian and maximum likelihood methods and provide a phylogenetic hypothesis for the family that recovers strong support for the monophyly of all subfamilies and resolves relationships among a large proportion of chrysopine genera. Chrysopinae tribes Leucochrysini and Belonopterygini were recovered as monophyletic sister clades, while the species‐rich tribe Chrysopini was rendered paraphyletic by Ankylopterygini. Relationships among the subfamilies were resolved, although with relatively low statistical support, and the topology varied based on the method of analysis. Greatest support was found for Apochrysinae as sister to Nothochrysinae and Chrysopinae, which is in contrast to traditional concepts that place Nothochrysinae as sister to the rest of the family. Divergence estimates suggest that the stem groups to the various subfamilies diverged during the Triassic‐Jurassic, and that stem groups of the chrysopine tribes diverged during the Cretaceous.     

Fire history of an isolated subalpine mountain range of the Intermountain Region,United States

Fire has historically been an important ecological component of forests in the Intermountain Region of the northwestern United States. This study is set in a small biogeographically disjunct mountain range. Our research objectives were to (1) investigate the historical frequency, severity, size, and spatial pattern of fire; (2) determine if and how fire regimes have changed since Euro-American settlement; and (3) compare how fire regimes of a small isolated range compare to nearby, but considerably larger, mountain agglomerations. Our findings suggest that this mountain range has historically supported fires typified by small size and high frequency, resulting in a high degree of spatial pattern complexity compared to mountain agglomerations. We also found disparity in size and burn severity solely within the study area based on the bisecting Continental Divide. Since the advent of Euro-American settlement in the 1870s, fire frequency and sizes of individual fires in the West Big Hole Range have significantly decreased resulting in an estimated 87% reduction in area burned. We discuss potential relationships of mountain range isolation and fire regimes in the Intermountain Region. Furthermore, we suggest that the relative small size of this mountain range predisposes it to greater anthropogenic effects upon fire occurrence.     

Isolation and culture of cells derived from human cerebral microvessels

Summary Microvessels were isolated from non-neoplastic human cerebral cortical fragments resected for treatment of intractable seizure disorder. The microvessels were incubated in modified Lewis medium with 20 or 30% fetal bovine serum. Within 1–2 weeks, two cell populations emerged from the isolates. One type of cells had polygonal morphology, showed density-dependent contact inhibition at confluence in vitro, showed lectin-binding characteristics of endothelium (but only moderate positivity for factor VIII antigen), demonstrated induction of -glutamyl trans-peptidase when exposed to astrocyte-conditioned media, and responded to insulin by a pronounced increase in DNA synthesis. The other variety of cells grew in vitro more slowly in irregular strands separated by clear zones, showed ultrastructural features of smooth muscle, and isoelectric focusing of cell proteins revealed the presence of smooth-musclespecific -isoactin. Both types of cells could be serially subcultured. The ability to isolate and grow the two cell types, tentatively identified as human cerebral microvascular endothelium and smooth muscle, may facilitate studies of human blood-brain barrier function as well as the pathogenesis of cerebral microangiopathies unique to the human brain.Funded by Canadian Heart Foundation, Heart and Stroke Foundation of Ontario and UCLA Biomedical Research Support Grant     

The cellular and molecular regulation of 1,25(OH)2D3 production

The synthesis of 1,25(OH)₂D₃ is a critical control point in the regulation of calcium metabolism, and possibly in the growth and differentiation of a number of cell types. This paper reviews our current understanding of the regulation of this process at the cellular and molecular levels, with the emphasis on the mechanisms of feedback control 1,25(OH)₂D₃ itself, control of parathyroid hormone, the roles of cyclic AMP dependent protein kinase and protein kinase C, and the interaction between the various intracellular regulators of 1,25(OH)₂D₃ production.     

Aerial Dispersal and Epiphytic Survival of Pseudomonas syringae during a Pretest for the Release of Genetically Engineered Strains into the Environment

Prospective experimental field evaluation of genetically engineered microorganisms, such as microbial pest control agents, raises issues of how to properly ascertain their fate and survival in the environment. Field trials with recombinant organisms must reflect requirements for sampling and monitoring. Field trials were conducted at Tulelake, Calif., to monitor the numbers of viable cells of a nonrecombinant strain of Pseudomonas syringae that entered the atmosphere and landed on plants and soil during and after an aerosol spray application. An exponential decrease in numbers of viable cells deposited at increasing distances from three sprayed plots was observed. The relative rate of survival of cells sprayed directly on plants was more than 10 times higher than that of cells dispersed through the air to similar adjacent plants. Results are being used to gain experience with the characteristics of a release site that influence containment or dispersal and to develop appropriate sampling methodologies for evaluating survival and dispersal characteristics of genetically engineered bacteria released into the environment. The ability to make predictions about microbial dispersal and survival will reduce the uncertainties associated with environmental releases of recombinant organisms.     

Use of diathermy for weeding heterogeneous tissue cultures

Summary Cultures generated from tissues consisting of multiple types of cells are often heterogeneous. Unless the cell type of interest has or can be given some selective growth advantage it may be overgrown by other cells. While developing techniques for the tissue culture of microvascular endothelial cells we evaluated an electrosurgical generator (diathermy) to selectively kill nonendothelail cells. Primary cell cultures were observed at ×100 magnification under phase contrast microscopy and a needle electrode apposed to the cell to be destroyed. A return electrode was constructed by placing a sterile clip in contact with the culture medium. The diathermy power setting controlled the area of lysis. Use of this technique allowed weeding of unwanted cells without damage to endothelial cells, which were able to grow to confluence in pure culture. Dr. Marks receives a Medical Postgraduate Research Scholarship from the National Health and Medical Research Council of Australia. Financial support was received from the Leo Leukaemia and Cancer Research Trust and the Scleroderma Association of New South Wales.     

Larval development and metamorphosis in the marine pulmonate Amphibola crenata (Mollusca: Pulmonata)

The development of the free-swimming veliger of Amphibola is followed from hatching to settlement, and the larval structures compared with those of post-metamorphic juveniles and adult snails. Observations of living specimens and light-microscope sections were combined with scanning electron microscopy to build up a composite picture of veliger structure.
Four stages in the development of veligers are recognized, each being characterized by the appearance of organ systems such as the mantle cavity, larval heart, adult heart and kidney, and larval pallial gland. At or after metamorphosis, the larval systems (heart, kidney and pallial gland) disappear, and the developing adult organs move to the positions characteristic of adult snails.
Organogenesis in Amphibola veligers is compared with that of prosobranch and opisthobranch larvae, and with that of pulmonate larvae with direct development. The closest similarity is seen to be with opisthobranch veligers.     

Isolation and Genetic Analysis of Caulobacter Mutants Defective in Cell Shape and Membrane Lipid Synthesis

In this paper we report the isolation, characterization and genetic analysis of several C. crescentus mutants altered in membrane lipid synthesis. One of these, a fatty acid bradytroph, AE6002, was shown to be due to a mutation in the fatA gene. In addition to the presence of the fatA506 mutation, this strain was found to contain two other mutations, one of which caused the production of a water-soluble brown-orange pigment (pigA) and another which caused formation of helical cells (hclA). Expression of the latter two phenotypes required complex media and both were repressed by glucose. However, the lesions were mapped to loci that are separated by a substantial distance. The hclA and the fatA genes mapped close together, possibly implying that comutation had occurred in AE6002. Data are presented that allow the unambiguous identification of a second Fat gene (fatB) in C. crescentus. The map position of another mutation in membrane lipid biogenesis, the glycerol-3-PO₄ auxotroph gpsA505, was also determined. During this study the flaZ gene was fine-mapped and the positions of proC and rif changed from the previously reported location.     

Turbo Tree: a fast algorithm for minimal trees

A branch and bound algorithm is described for searching rapidlyfor minimal length trees from biological data. The algorithmadds characters one at a time, rather than adding taxa, as inprevious branch and bound methods. The algorithm has been programmedand is available from the authors. A worked example is givenwith 33 characters and 15 taxa. About 8 x 10¹² binary treesare possible with 15 taxa but the branch and bound program findsthe minimal tree in <5 min on an IBM PC. Received on January 15, 1987; accepted on February 23, 1987     

Protein Patterns of Growing and Starved Cells of a Marine Vibrio sp.

Fingerprint protein patterns were produced by two-dimensional polyacrylamide electrophoresis on lysed cells of a Vibrio sp., Ant-300, which were prepared from growing and starved cultures. The cells were labeled with [³⁵S]methionine during growth and subsequently starved for up to 30 days. Samples were taken at selected time points representing stages in the starvation-survival process. Unlabeled starved cells were allowed to recover in the presence of [³⁵S]methionine to determine protein changes associated with the recovery from starvation. All growth conditions produced similar protein fingerprints; however, some protein spots disappeared, whereas others were seen only during starvation.