Disease relevance of ry

• Its specific activity is indistinguishable from that of the enzyme purified from fruit flies [Doyle, Burke, Chovnick, Dutton, Whittle and Bray (1996) Eur. J. Biochem. 239, 782-795], and it appears to be more active than recombinant xanthine dehydrogenase produced with the baculovirus system [1].
• This RNA exhibited tissue-specific distribution that may be pertinent to XD- and XO-mediated oxygen radical injury in ischemia/reperfusion and inflammation [2].
• The method employs the maroon-like (ma-1) gene and depends on the known hypersensitivity of ma-1 flies lacking xanthine dehydrogenase (XDH) activity to killing by treatments with aqueous purine solutions [3].

High impact information on ry

• The tissue distribution of XDH activity in all the strains was normal [4].
• The estimated rate of gene transfer by gene conversion at this region, which is close to an inversion breakpoint, is lower than previous estimates obtained experimentally at the rosy (ry) gene in Drosophila melanogaster [5].
• The complete nucleotide sequence of human XD was determined; the deduced amino acid sequence encoded a protein of 1336 amino acid residues of M(r) 147,782 [2].
• We isolated cDNAs encoding xanthine dehydrogenase (XD; xanthine:NAD+ oxidoreductase, EC 1.1.1.204) from a human liver cDNA library [2].
• Human XD possessed many of the signature sequences typical of XDs from flies and rodents, including an unusual cysteine distribution, a potential 2Fe/2S binding site, and a putative molybdopterin cofactor binding domain [2].

Biological context of ry

• Histochemical and antibody staining of frozen sections, as well as thin layer chromatography studies of several adult genotypes serve to examine some of the factors and genic interactions that may be involved in transport of XDH, and in eye pigment formation [6].
• In a related study (T. P. Keith et al. 1987), the genomic and cDNA sequences are extended through the 3' end of the gene; the combined sequences define the processing pattern of the rosy transcript and predict the amino acid sequence of XDH [7].
• Molecular population genetics of Xdh and the evolution of base composition in Drosophila [8].
• Here we report such data from the protein-coding region of xanthine dehydrogenase (Xdh) in 22 species of Drosophila [8].
• Xanthine dehydrogenase (XDH) mRNA levels were measured in a number of mutants and natural variants affecting XDH gene expression [9].

Anatomical context of ry

• The rosy position effect on XDH production may be assayed in whole larvae and larval fat body tissue as well as in adults [10].
• Three lines of evidence are presented demonstrating that XDH is sequestered within specific vacuoles, the type II pigment granules [6].
• Rosy position effect variants exhibit a variegated phenotype with respect to xanthine dehydrogenase activity in malpighian tubules [11].

Associations of ry with chemical compounds

• Recent crystal structures of xanthine dehydrogenase, xanthine oxidase and related enzymes have paved the way for a detailed structural and functional analysis of these enzymes [1].
• We induced 376 new mutations with 1-ethyl-1-nitrosourea (ENU) and screened them to isolate those that reduced the amount of XDH protein produced, but did not change the properties of the enzyme [7].
• We report here an in vivo investigation of the oxygen defense role of uric acid through an analysis of mutants of the rosy (ry) gene of Drosophila melanogaster [12].
• We show that urate-null mutants of the ry locus are hypersensitive to paraquat, ionizing radiation, and hyperoxia [12].
• Molybdenum-containing enzymes of the hydroxylase class (such as xanthine dehydrogenase, aldehyde oxidase and nicotinate dehydrogenase) require a terminal sulphur atom attached to the molybdenum to hydroxylate their specific substrates [13].

Other interactions of ry

• Evidence for the identity of in vitro reconstituted xanthine dehydrogenase from ma-l mutants with wild type enzyme is presented [14].
• The walk includes the DNA for the rosy and Ace loci, which code for xanthine dehydrogenase and acetylcholinesterase, respectively [15].
• The extremely close similarity in frequency distributions of the alleles between populations for both the xanthine dehydrogenase and esterase-5 loci, despite differences in allele frequency distribution between loci, strongly emphasizes the importance of migration in influencing genic diversity in these populations [16].

Analytical, diagnostic and therapeutic context of ry

• After treatment of developing cultures with a 6-mM purine solution, only those individuals possessing 25% or greater XDH activity survive to eclosion [3].
• To clone the Bombyx xanthine dehydrogenase (XDH) gene as a dominant marker for silkworm transgenesis, we performed nested reverse transcriptase-polymerase chain reaction (RT-PCR) using embryonic mRNA and primers designed from the conserved region of Drosophila and rat XDH genes [17].
• The remaining eleven ry alleles code for XDH molecules that retain some antigenic similarities to the wild type enzyme as assessed by immunoelectrophoresis and six of these eleven were capable of intragenic complementation [18].

References