Studies on the xanthine oxidase activity of mammalian cells

Xanthine oxidase in man is confined to but a few tissues and is absent from cultured cell strains. In rodents, however, the enzyme is more widely distributed among the tissues and can be demonstrated in most cell lines. Rodents possess the enzyme uricase and are therefore able to carry purine catabolism one step further than man. Preliminary results suggest that uricase is restricted to but a few rodent tissues and is absent from cultured rodent cells. Hence it may be that in each species only the final enzyme of purine catabolism is tissue restricted. In other experiments, mammalian cells were grown in the presence of compounds known to induce xanthine oxidase in a eukaryotic fungus (Aspergillus nidulans) . These compounds did not induce the enzyme in mammalian cells.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44184/1/10528_2004_Article_BF00487339.pd

Analysis of the mitochondrial and nuclear genomes of two basidiomycetes, Coprinus cinereus and Coprinus stercorarius

The mitochondrial and nuclear genomes of Coprinus stercorarius and C. cinereus were compared to assess their evolutionary relatedness and to characterize at the molecular level changes that have occurred since they diverged from a common ancestor. The mitochondrial genome of C. stercorarius (91.1 kb) is approximately twice as large as that of C. cinereus (43.3 kb). The pattern of restriction enzyme recognition sites shows both genomes to be circular, but reveals no clear homologies; furthermore, the order of structural genes is different in each species. The C. stercorarius mitochondrial genome contains a region homologous to a probe derived from the yeast mitochondrial var1 gene, whereas its nuclear genome does not. By contrast, the C. cinereus nuclear, but not mitochondrial, genome contains a region homologous to the var1 probe. Only a small fraction of either the nuclear or mitochondrial genomes, perhaps corresponding to the coding sequences, is capable of forming duplexes in interspecies solution reassociations, as measured by binding to hydroxylapatite. Those sequences capable of reassociating were found to have approximately 15% divergence for the mitochondrial genomes and 7%–15% divergence for the nuclear genomes, depending on the conditions of reassociation.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46959/1/294_2004_Article_BF00447385.pd