Cm. Uhlar et al., WALLABY SERUM AMYLOID A PROTEIN - CDNA CLONING, SEQUENCE AND EVOLUTIONARY ANALYSIS, Scandinavian journal of immunology, 43(3), 1996, pp. 271-276
A serum amyloid A (SAA) clone was isolated from a Tammar wallaby cDNA
library, the most distantly related mammalian species for which an SAA
has been described to date. The clone predicts a premolecule of 127 a
mino acids with good homology to other mammalian SAAs, and consists of
an 18 residue leader peptide and a mature protein of 109 amino acids.
Evolutionary analysis at both the protein and nucleotide level indica
te that the wallaby SAA clone clusters with the acute phase SAAs. Howe
ver, as the SAA superfamily has undergone concerted evolution it is no
t possible to determine at this point which acute phase SAA it is most
like. The grouping of wallaby SAA inside the acute phase SAA cluster
demonstrates that at least some of the duplication events giving rise
to multiple acute phase genes occured prior to the divergence of the e
utherian and metatherian mammals.