Molecular characterisation of the tammar wallaby (Macropus eugenii) CD3 epsilon chain cDNA

The cDNA encoding the epsilon chain of the tammar wallaby CD3 complex (CD3 epsilon;) was isolated by PCR. This is the first CD3 component to be cloned in a marsupial. The tammar wallaby cDNA coding region was 61.7 and 63.0%, identical to the human and mouse cDNA coding sequences, respectively. Simil arly, the predicted amino acid sequence was 56.5 and 52.9% identical to the human and mouse sequences. When compared with other known CD3 epsilon pept ide sequences. the most conserved region of the tammar wallaby CD3 epsilon chain peptide was the cytoplasmic domain and the least conserved was the ex tracellular portion. Phylogenetic reconstruction based on the deduced amino acid sequence placed the tammar wallaby sequence in its expected position outside of all the eutherian mammals. (C) 2001 Elsevier Science Ltd. All ri ghts reserved.