ELECTROPHORETIC POLYMORPHISM OF A HAMSTER PENTRAXIN, FEMALE PROTEIN (AMYLOID-P COMPONENT)

Serum amyloid P protein (SAP) is a ubiquitous vertebrate protein disti nguished by its conservative evolution and paucity of polymorphic form s. The SAP homologue in the Syrian hamster (Mesocricetus auratus), cal led Female Protein [FP(SAP)] is unique because its synthesis is contro lled by sex hormones. These observations were limited to the commercia lly available standard Syrian hamsters that are descendants of three l ittermates captured in Syria in 1930., The authors examined FP(SAP) ex pression in nine inbred lines of Syrian hamsters that were derived fro m 12 wild hamsters captured in 1971. In general, regulation of FP(SAP) was similar in the new wild hamster strains, although a novel electro phoretically slower FP(SAP) was found in three of the strains, The slo w FP(SAP) was not distinguished by size, antigenicity, binding capacit y, or regulation. The electrophoretic difference was still apparent af ter deglycosylation. Hybrid offspring coexpressed both fast and slow F P monomers and formed a unique hybrid pentamer that had a new mobility between the fast and slow parent FP(SAP), The origin of this unusual polymorphism could be related to the amyloidogenesis associated with e xpression of FP(SAP) in the standard Syrian hamster.