Outer dense fibre proteins from human sperm tail: molecular cloning and expression analyses of two cDNA transcripts encoding proteins of similar to 70 kDa
C. Peterson et al., Outer dense fibre proteins from human sperm tail: molecular cloning and expression analyses of two cDNA transcripts encoding proteins of similar to 70 kDa, MOL HUM REP, 5(7), 1999, pp. 627-635
The outer dense fibres (ODF) are a main cytoskeletal structure of the sperm
tail. Despite their importance in the morphology and function of the sperm
tail, their constituents are poorly described. Here we investigate the pro
tein composition of human outer dense fibres. Our results suggest that huma
n ODF consist of about 10 major and of at least 15 minor proteins, where al
l major proteins are ODF1, ODF2 or ODF2-related proteins. From a human test
is cDNA library, we isolated two slightly different cDNAs encoding ODF2 pro
teins of similar to 70 kDa. Human ODF2 cDNAs and their encoded proteins are
very similar to those isolated from rat and mouse pointing to a high evolu
tionary pressure! residing on these proteins. Transcription of ODF2 is rest
ricted to testis tissue and more specifically to round spermatids as was de
monstrated by a non-radioactive in-situ hybridization. ODF2 proteins were d
etected in the sperm tail. Their distribution along the length of the sperm
tail shows that the ODF normally extend to about half the principal piece
of the sperm tail. The former result opens the possibility for a screening
regarding the distribution of sperm tail proteins related to motility disor
ders.