A novel dynein-related transcript (designated DNEL1) from human adult testis has been identified that can encode a protein with a size of 91087 Da. The complete nucleotide sequence of the open reading frame is the first to be described for a human dynein-related gene. Northern blot analysis of mRNA from 16 different tissues has shown that DNEL1 is expressed specifically in testis. Analysis of somatic cell hybrids has mapped DNEL1 to Chromosome (Chr) 17. Analysis of a panel of 129 whole genome radiaton hybrid clones including 17q22-q25.3 has placed DNEL1 in 17q distal to the ERBA2L locus. DNEL1 shares a high degree of sequence identity and amino acid similarity with the C-terminal region of the outer arm axonemal dynein beta-heavy chains derived from sea urchin and other species, but not to any gene encoding dynein intermediate or light chains described to date. The close similarity of DNEL1 to the C-terminal part of the axonemal beta-heavy chain may suggest an origin from a common progenitor gene and the testis-specific pattern of expression a possible role in sperm development or motility.