Characteristics of transplanted mouse myeloproliferative disease developed after repeated injections of granulocytic colony-stimulating factor.

Transplanted myeloproliferative disease developed in mice against the background of repeated injections of granulocytic CSF was characterized using morphological and molecular biological methods. It was demonstrated that transplanted myeloproliferative disease had a non-viral nature and is probably induced by repeated injections of granulocytic CSF. Tumor cells actively populate the liver of sick animals, which leads to their rapid death. Expression of Myc, Abl, G-CSF, and MPO genes is enhanced, which is typical of myeloid neoplastic transformation.

Five RecA-like proteins of Schizosaccharomyces pombe are involved in meiotic recombination.

The genome of Schizosaccharomyces pombe contains five genes that code for proteins with sequence similarity to the Escherichia coli recombination protein RecA: rad51+, rhp55+, rhp57+, rlp1+, and dmc1+. We analyzed the effect of deletion of each of these genes on meiotic recombination and viability of spores. Meiotic recombination levels were different from wild type in all recA-related mutants in several genetic intervals, suggesting that all five RecA homologs of S. pombe are required for normal levels of meiotic recombination. Spore viability was reduced in rad51, rhp55, and rhp57 mutants, but not in rlp1 and dmc1. It is argued that reduction of crossover is not the only cause for the observed reduction of spore viability. Analysis of double and triple mutants revealed that Rad51 and Dmc1 play major and partially overlapping roles in meiotic recombination, while Rhp55, Rhp57, and Rlp1 play accessory roles. Remarkably, deletion of Rlp1 decreases the frequency of intergenic recombination (crossovers), but increases intragenic recombination (gene conversion). On the basis of our results, we present a model for the involvement of five RecA-like proteins of S. pombe in meiotic recombination and discuss their respective roles.

[Cloning and characterization of the homologue of the Saccharomyces cerevisiae gene in Drosophila melanogaster]. / Klonirovanie i kharakteristika gomologa gena RAD23 Saccharomyces cerevisiae u Drosophila melanogaster.

RAD23 is an evolutionary conserved protein, which is essential for DNA excision repair. It is believed that this protein is present in all eukaryotic organisms from yeast to mammals. In this work, molecular cloning of the Drosophila melanogaster RAD23 gene and an analysis of the encoded protein are reported.