Studies of ribosomal proteins of yeast species and their hybrids gel electrophoresis and immunochemical cross-reactions

Summary The cytoplasmic ribosomal proteins (r-proteins) of seventeen yeast species of the genera Saccharomyces and Kluyveromyces were analyzed by one-dimensional gradient polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulphate. The electrophoretic patterns of cytoplasmic r-proteins from different species display extensive differences in both the 40S and the 60S subunit. Relatedness of species suggested by r-protein patterns correlates well with that based on DNA/DNA homology (Bicknell and Douglas 1970). Immunochemical cross-reactions and antibiotic susceptibility tests were also used to compare different species.Analyses of r-proteins from two different interspecific hybrids showed that their ribosomes were hybrid, containing r-proteins from both parents. These findings are discussed in relation to the evolution of yeast species and the regulation of expression of r-proteins in cucaryotes.     

A new species of Eugenia (Myrtaceae) from Venezuela

Eugenia mcvaughii is described from a forest remnant of the Jardin Botánico of Caracas, Venezuela. Found also in the hills adjacent to Caracas, it may be considered as an endemic species of the Interior Coastal Cordillera.     

New species from the summit of Cerro Guaiquinima,Venezuela

Three new species,Lubaria szczerbanii (Rutaceae),Croton guaiquinimae (Euphorbiaceae), andStomatochaeta colveei (Asteraceae), are described from the summit of Cerro Guaiquinima, Venezuela. The generic affinities betweenLubaria andMyllanthus, and betweenStomatochaeta andStenopadus are discussed.     

New taxa from the Avila and Naiguatá Mountains,Venezuela

Ten new species (Billbergia manarae, Croizatia naiguatensis, Croton huberi, Rinorea oraria, Anaectocalyx manarae, Linociera avilensis, Cynanchum beatricis, C. manarae, Matelea costanensis, and M. manarae) are described in preparation for the forthcoming Flora of Avila and Naiguatá.     

Banding studies on the polytene chromosomes of Rhynchosciara hollaenderi

C-, Q-, H-, and Ag-banding have been carried out on the polytene chromosomes of Rhynchosciara hollaenderi. The results of these techniques are presented and are correlated with the molecular data which exists for Rhynchosciara polytene chromosomes. By systematic organization of both banding and molecular data, we have attempted to give as complete a picture as possible of the characteristics of the differentially banding regions. This presents an organized method of approaching mechanisms of banding in terms of structural and functional aspects of the intact chromosome. Polytene chromosomes are particularly suited for this type of analysis and with them, both developmental and evolutionary changes can be conveniently utilized for additional insights into the functions of banding regions.     

Immobilization of tyrosinase within polyacrylamide gels

The enzyme tyrosinase (E.G. 1.14.18.1) has been immobilized in a polyacrylamide gel and intermittently assayed for enzyme activity over a period of 19 days using phenol as the substrate. The results of these studies indicate that the immobilized enzyme could be incorporated into a system to detect phenol and related compounds that are found in industrial effluents and as surface water contaminants.     

Genomic information infrastructure after the deluge

Maintaining up-to-date annotation on reference genomes is becoming more important, not less, as the ability to rapidly and cheaply resequence genomes expands.