TOOLS FOR STUDYING THE CHLOROPLAST GENOME IN THE TRITICEAE (GRAMINEAE): AN ECORI MAP,A DIAGNOSTIC DELETION,AND SUPPORT FOR BROMUS AS AN OUTGROUP

Data on variation in the chloroplast genome can be used to estimate the phylogeny of the wheat tribe (Triticeae), but two tools have been needed—a restriction site map for at least one frequent-cutting enzyme, and a well-supported outgroup. This paper presents an EcoRI map, as well as maps for six other restriction enzymes, for two members of the tribe (Elytrigia repens and Secale cereale). These are compared to the maps for Bromus tectorum, a possible outgroup, and for Briza maxima, Lolium perenne, and Festuca rubra, other members of the same subfamily (Pooideae). A unique deletion of ca. 700 base pairs was discovered that provides a distinctive marker for the cytoplasm of plants with the S genome. The deletion also appears in Dasypyrum villosum (V genome). Cladograms based on restriction site data are unequivocal in the support for Bromus tectorum as a near relative of the Triticeae; the chloroplast phylogeny is very similar to the morphological cladogram for a comparable set of taxa.     

Distinguished Lecture in Archeology: Breaking and Entering the Ecosystem—Gender, Class, and Faction Steal the Show

This article was presented as the third annual Distinguished Lecture in Archeology at the 90th annual meeting of the American Anthropological Association, November 22, 1991, in Chicago, Illinois.     

Identification of HLA-B44 subtypes associated with extended MHC haplotypes

The HLA class I antigen B44 is found in each of two different extended major histocompatibility haplotypes (allele combinations of HLA-B, HLA-DR, and complement genes BF, C2, C4A, and C4B in linkage disequilibrium). Using isoelectric focusing, two variants of HLA-B44 were identified. The basic variant was found in all cell lines with the extended haplotype HLA-B44, DR7, FC31, and the acidic variant in all cell lines with the extended haplotype HLA-B44, DR4, SC30. The occurrence of each antigen variant with a unique extended haplotype explains previous observations concerning the nonrandom association of B44 variants with DR antigens.     

Two new species of coccidia (Apicomplexa: Eimeriidae) from Madagascar Gekkonids

Two new species of coccidia (Apicomplexa: Eimeriidae) are described from the Madagascar giant day gecko, Phelsuma madagascariensis grandis, and the Golddust day gecko, P. laticauda. Both species of coccidia were found to infect the anterior one-half of the small intestine. Oocysts of Eimeria brygooi n. sp. are spherical or subspherical, 23.0 X 21.3 (18.8-25.2 X 16.4-23.2)micron; shape index (L/W) 1.1 (1.0-1.2). A micropyle, oocyst residuum, and polar granule are absent. Sporocysts are ovoid, 9.2 X 7.9 (8.0-10.0 X 7.2-8.8) micron; shape index 1.2 (1.0-1.3), with a Goussia-type suture; Stieda and substieda bodies are absent. A sporocyst residuum is present, 4.2 X 3.0 (3.2-6.4 X 2.4-4.0) micron. Sporozoites are elongate, with anterior and posterior refractile bodies. This coccidian was found to infect five of six (83%) P. m. grandis and one of five (20%) P. laticauda examined. Oocysts of Isospora gekkonis n. sp. are spherical or subspherical, 24.2 X 22.0 (21.6-26.4 X 20.0-23.6) micron; shape index 1.1 (1.0-1.2). A micropyle and oocyst residuum are absent; polar granule present. Sporocysts are ovoid, 12.2 X 9.4 (11.2-12.8 X 8.4-10.0) micron, with Stieda and substieda bodies; shape index 1.3 (1.2-1.4). A sporocyst residuum is present, either compact, 5.1 X 4.2 (4.0-7.2 X 3.2-5.6) micron or diffuse. Sporozoites are elongate, with anterior and posterior refractile bodies. Isospora gekkonis was found in two of six (33%) P. m. grandis and one of five (20%) P. laticauda. In addition, oocysts of Cryptosporidium sp. were found in the cloacas of two of six (33%) necropsied P. m. grandis.     

Comparisons of tests for aneuploidy

The fundamental problems that face us in the development of suitable assay systems for the detection of potentially aneugenic (aneuploidy-inducing) chemicals include: (a) the diversity of cellular targets and mechanisms where perturbations of structure and function may give rise to changes in chromosome number, and (b) the phylogenetic differences that exist between species in their mechanism and kinetics of cell division and their metabolic profiles. A diverse range of assay systems have been developed, which have been shown to have potential for use in the detection of either changes in chromosome number or of perturbations of the events which may be causal in the induction of aneuploidy.

Chromosome number changes may be detected cytologically by karyotypic analysis, or by the use of specialised strains in which aneuploid progeny may be observed due to phenotypic differences with aneuploid parental cells or whole organisms. Techniques for the detection of cellular target modifications range from in vitro studies of tubulin polymerisation to observations of the behaviour of various cellular organelles and their fidelity of action during the division cycle.

The diversity of mechanisms which may give rise to aneuploidy and the qualitative relevance of events observed in experimental organisms compared to man make it unlikely that the detection and risk assessment of the aneugenic activity of chemicals will be possible using a single assay system. Optimal screening and assessment procedures will thus be dependent upon the selection of an appropriate battery of predictive tests for the measurement of the potentially damaging effects of aneuploidy induction.     

Mapping and sequencing of a gene from myxoma virus that is related to those encoding epidermal growth factor and transforming growth factor alpha.

Myxoma virus, a Leporipoxvirus and agent of myxomatosis, was shown to possess a gene with the potential to encode an epidermal growth factorlike factor. Its relationship to other members of this family, including the poxvirus growth factors from Shope fibroma virus and vaccinia virus, was analyzed. Alignment of DNA sequences and related open reading frames of myxoma virus and Shope fibroma virus indicated colinearity of genes between these poxviruses.     

Expression of the β-subunit of β-conglycinin in seeds of transgenic plants

Soybean (Glycine max (L.) Merr.) seeds contain the storage protein -conglycinin, encoded by a multigene family. -Conglycinin consists of three subunits; , , and . A genomic clone for a -subunit of -conglycinin has been characterized by restriction-enzyme mapping and hybrid selected in-vitro translation followed by immunoprecipitation. In order to determine the developmental regulation of this -subunit gene, its expression was studied in seeds of transgenic petunia (Petunia hybrida) and tobacco (Nicotiana tabacum L.) plants. The -subunit expressed in seeds of petunia and tobacco was recognized by anti--conglycinin serum at a relative molecular mass of 53 000, equivalent to that of the native protein. Separation of the petunia-seed proteins by isoelectric focusing followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblot analysis showed that multiple isoelectric forms of the -subunit were produced. There was approximately a twofold variation in the accumulation of the -subunit protein in the mature seeds of transgenic petunia plants, each containing a single -subunit gene. However, the level of protein accumulation in mature seeds and the amount of -subunit mRNA in developing seeds was not correlated. Accumulation of the -subunit protein in transgenic seeds was less than the -subunit protein that accumulated in transgenic petunia seeds containing a single -subunit gene and less than the amount of the -subunit in mature soybean seeds which contain 8–13 -subunit genes. In transgenic tobacco plants, the accumulation of the -subunit protein in seeds was generally well correlated with the number of genes that were incorporated in the different transformants.Abbreviations kb kilobase - kDa kilodalton - M_r relative molecular mass - SDS-PAGE sodium dodecyl sulfate polyacrylamide gel electrophoresis     

C-terminal bombesin sequence requirements for binding and effects on protein synthesis in Swiss 3T3 cells.

The active-site serine of the extracellular beta-lactamases of Streptomyces cacaoi and Streptomyces albus G has been labelled with beta-iodopenicillanate. The determination of the sequence of the labelled peptides obtained after trypsin digestion of the denatured proteins indicate both enzymes to be class A beta-lactamases. Surprisingly the two Streptomyces enzymes do not appear to be especially homologous, and none of them exhibited a high degree of homology with the Streptomyces R61 DD-peptidase. Our data confirm that, as a family of homologous enzymes, class A is rather heterogeneous, with only a small number of conserved residues in all members of the class.