ABSTRACT
To contribute to the identification and analysis of novel genes, we undertook the study of a cosmid clone in the Xq27 region of human DNA. The cloned fragment was previously observed to have a high number of evolutionarily conserved sequences. In this genomic stretch of DNA we have identified sequence homologous to the U7 RNA gene including its potential regulatory elements. This paper describes the genomic organisation of this gene and its mapping to the Xq27.1 genomic sub-interval between the DXS1232 and DXS119 loci.
Subject(s)
Chromosome Mapping , Ribonucleoproteins, Small Nuclear/genetics , X Chromosome , Animals , Base Sequence , DNA , Genetic Markers , Humans , Molecular Sequence DataABSTRACT
To contribute to the isolation of genes within the q-24-qter region of the human X chromosome,we screened three cDNA libraries (human fetal brain, liver and skeletal muscle) with a cosmid clone containing a CpG island previously mapped in the q28 region. A full-length 2.1-kb cDNA clone was isolated (XIB); DNA databank searches revealed identity with an EST fragment (XAP-1), residing between the RCP/GCP and G6PD loci. The XIB coding region (909 bp) showed 44% amino acid (aa) identity to pig DNase I. Several conserved residues have been observed between these two genes including aa in the active site. XIB expressed a single transcript in adult heart and skeletal muscle, whereas, in some fetal tissues, two different-sized transcripts were seen. Zoo blot analysis showed a remarkable cross-species conservation. Expression and sequence of this novel gene are reported.
Subject(s)
Deoxyribonuclease I/genetics , X Chromosome , Adult , Amino Acid Sequence , Animals , Base Sequence , Binding Sites , Chromosome Mapping , Cloning, Molecular , Consensus Sequence , Conserved Sequence , Cosmids , DNA, Complementary , Deoxyribonuclease I/biosynthesis , Fetus , Fishes , Humans , Molecular Sequence Data , Muscle, Skeletal/enzymology , Myocardium/enzymology , Sequence Homology, Amino Acid , Sequence Homology, Nucleic Acid , Species Specificity , Transcription, GeneticABSTRACT
An EagI-EcoRI clone of human genomic DNA, p2-7, mapped to Xq24 has been sequenced. This analysis has confirmed the presence of a CpG island and has identified the first exon of the human LAMP2 gene, encoding a glycoprotein of the lysosomal membrane. Since the p2-7 clone corresponds to single-copy DNA, we can assign the human LAMP2 gene to Xq24.
