MOLECULAR-CLONING OF THE CDNA-ENCODING THE CONSTANT-REGION OF THE IMMUNOGLOBULIN-A HEAVY-CHAIN (C-ALPHA) FROM A MARSUPIAL - TRICHOSURUS-VULPECULA (COMMON BRUSHTAIL POSSUM)

A cDNA encoding the brushtail possum immunoglobulin A heavy chain cons tant region (C alpha) was isolated by screening a mesenteric lymph nod e cDNA library with a porcine C alpha exon 3 probe. The larger of the two positive clones isolated (Tv4a) consisted of 1325 bp of possum cDN A that included an open reading frame of 1191 bp. Its deduced amino ac id sequence had a high degree of sequence identity with known eutheria n C alpha sequences. This clone appears to encode the entire possum Ig A heavy chain constant region. The possum Ca sequence had a nucleotide sequence identity of 57.7% with porcine C alpha, 51% with mouse C alp ha, 46.7% with dog C alpha and 45.9% with human C alpha 2. The corresp onding amino acid identities were 46.7, 45.6, 49.4 and 49%, respective ly. (C) 1998 Elsevier Science B.V. All rights reserved.