In collaboration with Associate Professor Andrew Shelling (Department of Obstetrics and Gynaecology,
The University of Auckland) we recently discovered SPRASA, a sperm protein that is the target of antisperm
antibodies from some infertile men (Chiu et al. 2004). Since SPRASA is the antigen
for some antisperm antibodies and is only found in sperm we believe it has an essential
role in fertility. However, the function of SPRASA remains unknown. Structural homology
of SPRASA to other proteins of the c-type lysozyme/alpha-lactalbumin family, as
well as the localisation of SPRASA to the inner acrosomal membrane of sperm suggests
SPRASA may interact with carbohydrates on oocyte proteins. Our current studies are
aimed at defining the role of SPRASA in human and animal fertility.
Human sperm showing SPRASA staining in the acrosome (Red). Nuclei are stained with
haemotoxylin (Blue).
Current investigations include
- What is the incidence of SPRASA-reactive antibodies in infertile couples?
- Are mutations in the SPRASA gene associated with infertility?
- Which species express SPRASA?
- Is the structure of SPRASA the same in all species?
- Does neutralisation of SPRASA affect fertility?
Funding for this work was provided by:
- The Marsden Fund of the New Zealand Royal Society
- The Maurice and Phyllis Paykel Trust
- The New Zealand Lotteries Board (Health)
- The University of Auckland Staff Research Fund
Major collaborators
- Professor PM Johnson, Dept Immunology University of Liverpool, UK
- Dr Vikki Abrahams, Dept Obstetrics and Gynecology, Yale University, USA.
