Identification of Mutations Associated with Macrofiber Formation in BACILLUS SUBTILIS

A search was made for the genes responsible for the production of helical macrofibers in the original collection of macrofiber-producing strains of B. subtilis. Two loci were identified: fibA, located between hisA and tag-1, and fibB, linked to cysB. fibA governs a short-lived division suppression phenomenon associated with the production of rudimentary fibers, whereas fibB appears to be responsible for a persistent division suppression and a more highly organized helical macrofiber. Both mutations are recovered from each of the original macrofiber-producing strains which also carried the div IV-B1 mutation responsible for minicell production. The latter mutation by itself is not sufficient, however, for the production of macrofibers. Other known mutations leading to division suppression that map in the same region are shown not to be allelic to fibA or fibB. Neither fib locus appears to be responsible for helix hand determination.     

Association between parasite load and orange,but not blue,male nuptial colouration in Etheostoma caeruleum

The hypothesis that males possessing more vivid nuptial colouration are of better quality with regard to individual measures of health such as parasite infection was investigated by taking spectral measurements of orange and blue bars in the nuptial males of a sexually dichromatic stream fish rainbow darter Etheostoma caeruleum to determine if male colouration in this species varied with parasite load in the form of black spot disease. The yellow chroma of orange bars, i.e. the relative contribution of wavelengths in the range of 550–625 nm to total brightness, was the only spectral measurement significantly associated with parasite counts. These results are discussed in the context of sexual selection and the potential of orange bars in E. caeruleum to serve as honest indicators of quality to potential mates.     

Genes coding for integration host factor are conserved in gram-negative bacteria.

A genetic system for the selection of clones coding for integration host factor and HU homologs is described. We demonstrate that the himA and hip genes of Serratia marcescens and Aeromonas proteolytica can substitute for the Escherichia coli genes in a variety of biological assays. We find that the sequence and genetic organization of the himA and hip genes of S. marcescens are highly conserved.     

Brill-Zinsser disease: report of a case in Canada

This report documents the occurrence of Brill-Zinsser disease in a 48-year-old woman who experienced typhus fever in a German concentration camp. This is the first report of a case of recrudescent typhus in a European immigrating to Canada following World War II. The last reported case of Brill-Zinsser disease in Canada occurred in 1953.