The lipocalin sperm coating lizard epididymal secretory protein family: mRNA structural analysis and sequential expression during the annual cycle ofthe lizard, Lacerta vivipara

The epididymal epithelial cells of the lizard (Lacerta vivipara) produce la rge amounts of specific proteins under androgenic control. Amongst them, a major protein family that binds to the head of spermatozoa, the lizard epid idymal secretory protein (LESP) family, has been identified as a member of the lipocalin superfamily. LESPs are composed of 9 elements that present an identical molecular mass of 18 000 Da but have a large range of pH (3.5 to 9). The structural analysis of this protein family was performed by the de termination and comparison of both the aminoterminal sequence of each eleme nt and the complete sequence of three specific LESP cDNA clones. When not i dentical, LESP elements present randomly dispatched nucleotide and amino ac id substitutions, indicating the existence of at least five LESP mRNA popul ations encoded by a multigenic family. We determined that these LESP genes ape differentially expressed during the annual epididymal cycle.