Identification of a ζ-Crystallin (Quinone Reductase)-like 1 Gene (CRYZL1) Mapped to Human Chromosome 21q22.1

Abstract

To identify a new gene(s) located on the yeast artificial chromosome (YAC) clone D142H8 that was mapped to human chromosome 21q22.1, purified YAC DNA from the clone was utilized directly as a probe to screen a human brain cDNA library after the suppression of human repetitive DNA. One cDNA clone hybridizing specifically to the YAC D142H8 DNA was identified. The clone has an insert of 1341 bp and the longest open reading frame of 349 amino acids. A search of GenBank revealed that the clone has a high degree of homology to ζ-crystallin (quinone reductase) at the amino acid level, and its nucleotide sequence represents the expressed sequence from the 50-kb segment of the human chromosome 21q11.1. Thus a new gene was namedCRYZL1(ζ-crystalline-like 1). Genomic Southern blot with total human and yeast DNAs suggests thatCRYZL1might be a single-copy gene. The fluorescencein situhybridization procedure was applied, and the results showed that the gene mapped to the human chromosome 21q22.1 subband. TheCRYZL1mRNA was expressed in heart, brain, skeletal muscle, kidney, pancreas, liver, and lungs but at different levels in different tissues.