A frequent allele codes for a truncated variant of semenogelin I, the major protein component of human semen coagulum

• Human semen coagulum predominantly consists of high molecular mass complexes of the seminal vesicle secreted semenogelin I (SgI) and semenogelin II (SgII). Here we describe a previously unknown variant of the SgI gene that is present at an allele frequency of similar to3% in the Swedish population. It gives rise to a protein with a molecular mass of 43 kDa, SgI(43), which compared with the 50 kDa variant, SgI(50), is lacking a tandem repeat of 60 amino acid residues that was probably deleted by homologous recombination. In spite of the size difference, SgI(43) has many properties in common with SgI(50), such as a very high iso-electric point and susceptibility to proteolytic degradation by prostate-specific antigen. Heterozygous carriers of the SgI(43) allele neither show impaired fertility nor do they significantly differ from individuals homozygous for I SgI(50) with respect to sperm parameters such as semen volume, sperm count and fraction of motile spermatozoa.

Subject headings

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Reproduktionsmedicin och gynekologi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Obstetrics, Gynaecology and Reproductive Medicine (hsv//eng)

Keyword

transglutaminase

semen semenogelin I/II

allele

coagulum

truncated

Publication and Content Type

art (subject category)

ref (subject category)