Sequence, expression, and chromosomal assignment of a human sperm outer dense fiber gene

Abstract

Outer dense fibers (ODFs) are located on the outside of the axoneme in the midpiece and principal piece of the mammalian sperm tail and may help to maintain the passive elastic structures and elastic recoil of the sperm tail. We have identified and describe here a human gene that is homologous to the Mst(3)CGP gene family of Drosophila melanogaster and encodes an ODF protein of 241 amino acids. The transcribed region has a size of approximately 1 kb and contains two exons of 416 bp and 406 bp, respectively, not including the 3' untranslated region. The gene is expressed in testis but not in human spleen, kidney, or brain and resembles in this respect the expression of the Drosophila Mst(3)CGP gene family in the male germline. An antiserum raised against a synthetic peptide derived from the N-terminus of the encoded sequence identified a protein of approximately 32 kDa in an extract of human sperm flagella. By Southern-blot analyses and in situ hybridization, the ODF gene was localized to band q22 of chromosome 8. The isolation of a human gene encoding a sperm tail protein may provide the ability to identify and investigate, on the molecular level, possible reasons for human male infertility that are dependent on flagellar disturbances.

Outer dense fibre protein 2 (ODF2) is a self-interacting centrosomal protein with affinity for microtubules

“…In addition, they may also support the axonemal beat by force transmission to the flagellar base (Lindemann, 1996). The widespread occurrence of ODFs in the sperm tails of animals with internal fecundation supports their importance for sperm morphology and function (Mortimer, 1997), and is in accordance with evolutionary conservation of ODF proteins in mammals (Burfeind and Hoyer-Fender, 1991;Gastmann et al, 1993;Hoyer-Fender et al, 1995;Brohmann et al, 1997;Hoyer-Fender et al, 1998;Petersen et al, 1999).…”

Moving to the beat: a review of mammalian sperm motility regulation

“…The successful cloning of several genes that code for keratin-like intermediate filament ODF proteins provides support for this hypothesis (Gastmann et al 1993;Morales et al 1994;Hoyer-Fender et al 1995Kim et al 1995;Burmester and Hoyer-Fender 1996;Kierszenbaum et al 1996;Tres and Kierszenbaum 1996;Brohmann et al 1997;Shao et al 1997;Schalles et al 1998;Zarsky et al 2003). To date, none of these ODF-specific genes has been targeted for mutation and, so, the true role of these proteins, and the role of the ODFs, remains somewhat speculative.…”

Haplo-deficiency of ODF1/HSPB10 in mouse sperm causes relaxation of head-to-tail linkage

“…The ODF1 protein has a molecular mass of w27 kDa with a high content of cysteine (between 13.7 and 17%) and proline (up to 10%) ( Van der Hoorn et al 1990, Burfeind & Hoyer-Fender 1991, Gastmann et al 1993, Morales et al 1994, Hoyer-Fender et al 1995. Cysteine and proline residues are mainly found in repetitive C-X-P tripeptide motifs present in the C-terminal end of ODF1.…”

“…Albeit C-X-P repeat frequency is variable, it seems not to affect male fertility in humans (Hofferbert et al 1993). ODF1 is conserved in evolution and, due to its a-crystalline domain, ODF1 has been assigned as a small heat shock protein (sHSP) leading to renaming into HSPB10 (Kuhn et al 1988, Gastmann et al 1993, Petersen et al 1999, Fontaine et al 2003. HSPs in general are essential molecular chaperones and execute strong cytoprotective effects by preventing the aggregation of mis-folded proteins.…”