Mechanisms underlying gametogenesis are complex and apparently divergent among metazoans. The DAZ (Deleted in Azoospermia) gene family provides one of the few lines of evidence that argue for evolutionary conservation of gametogenesis at the molecular level. DAZ family proteins carry two conserved domains, namely the ribonucleoprotein (RNP)-type RNA recognition motif (RRM) and the DAZ motif, an...

Because a microdeletion containing the DAZ gene is the most frequently observed deletion in infertile men, the DAZ gene was considered a strong candidate for the azoospermia factor. A recent evolutionary analysis, however, suggested that DAZ was free from functional constraints and consequently played little or no role in human spermatogenesis. The major evidence for this surprising conclusion ...

Mutations in Deleted in Azoospermia (DAZ), a Y chromosome gene, are an important cause of human male infertility. DAZ is found exclusively in primates, limiting functional studies of this gene to its homologs: boule, required for meiotic progression of germ cells in invertebrate model systems, and Daz-like (Dazl), required for early germ cell maintenance in vertebrates. Dazl is believed to have...

Early in development, a part of the embryo is set aside to become the germ cell lineage that will ultimately differentiate to form sperm and eggs and transmit genetic information to the next generation. Men with deletions encompassing the Y-chromosome DAZ genes have few or no germ cells but are otherwise healthy, indicating they harbor specific defects in formation or maintenance of germ cells....

The DAZ gene cluster on the human Y chromosome is a candidate for the Azoospermia Factor (AZFc). According to the current evolutionary model, the DAZ cluster derived from the autosomal homolog DAZL1 through duplications and rearrangements and is confined to Old World monkeys, apes and humans. To study functional and evolutionary aspects of this gene family we have isolated from a cynomolgus (Ol...

Members of the DAZ gene family encode RNA-binding proteins and have been shown to play a pivotal role in gametogenesis. In Xenopus, a DAZ-like gene encodes an RNA component of the germ plasm. We have identified a zebrafish DAZ homologue, zDazl. zDazl mRNA was expressed in gonads of both sexes. In ovary, it was localized in the cortex of oocytes. At the onset of embryogenesis, maternal zDazl mRN...

The amplification outcomes of two hearing aid prescriptions, NAL-NL1 and Digital Perception Processing (DPP), of nine moderate to moderately severe hearing-impaired adults were compared in the same digital hearing instrument. NAL-NL1 aims at optimizing speech intelligibility while amplifying the speech signal to a normal overall loudness level (Dillon, 1999). DPP focuses on restoring loudness b...

The DAZLA (DAZ Like Autosomal) gene on human chromosome 3 shares a high degree of homology with the DAZ (Deleted in AZoospermia) gene family on the Y chromosome, a gene family frequently deleted in males with azoospermia or severe oligospermia. The involvement of both DAZ and DAZLA in spermatogenesis is suggested by their testis-specific expression and their homology with a Drosophila male infe...