Katherine Belov, Gavan A. Harrison, Robert D. Miller, and Desmond W. Cooper
Abstract:
The immunobiology of marsupial IgE is poorly understood. As a first step towards the development of immunological reagents for marsupials and to obtain a further understanding of immunoglobulin evolution, a brushtail possum (Trichosurus vulpecula) mesenteric lymph node cDNA library was screened for the heavy chain constant region of IgE (Ce), using a partial Ce probe from the American marsupial, Monodelphis domestica. The cDNA sequence for T. vulpecula C was determined and found to be most similar to the M. domestica Ce sequence [(76%) at the amino acid level]. T. vulpecula Ce has amino acid sequence similarities ranging from 43-52% with various eutherian Ce sequences. The secondary structure of T. vulpecula Ce, based on loops formed by internal disulfide bonds, more closely resembles rodent Ce than the American marsupial sequence.