Molecular cloning of the brushtail possum (Trichosurus vulpecula) immunglobulin E heavy chain constant region

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 (C epsilon), using a partial C epsilon probe from the American marsupial, Monodelphis domestica. The cDNA sequence for T. vulpecula C epsilon was determined and found to be most similar to the M. domestica C epsilon sequence [(76%) at the amino acid level]. T. vulpecula C epsilon has amino acid sequence similarities ranging from 43-52% with various eutherian C epsilon sequences. The secondary structure of T. vulpecula C epsilon, based on loops formed by internal disulfide bonds, more closely resembles rodent C epsilon than the American marsupial sequence. (C) 2000 Elsevier Science Ltd. All rights reserved.