Ten cDNA clones derived from chicken spleen cell mRNA have been partially sequenced and the genes which encode the mRNAs have been located within the linkage map of the chicken genome. The sequences of five of these clones show strong homology to known mammalian genes, the remainder show little homology to sequence present in the current databases. Interestingly, one of these clones appears to be the chicken homologue of the mammalian peptide transporter gene TAP2 and is located within the major histocompatibility complex. Two other clones are homologous to genes involved in protein synthesis and these are tightly linked in chickens, as in mice. These results suggest that partial sequencing and mapping of clones from selective cDNA libraries may be an efficient way of adding candidate genes to the chicken linkage map and that on a local scale there may be some conservation of grouping of genes between chickens and mammalian species.