Assignment of the Equus caballus interleukin 8 gene (IL8) to chromosome 3q14.2->q14.3 by in situ hybridization

Human interleukin 8 (IL-8) is an anti-infl ammatory cytokine. A signifi cant increase of the IL-8 concentration has been found in the plasma of marathon runners (Suzuki et al., 2000) and a similar upregulation of this interleukin was recently detected in lymphocytes of horses immediately after intense exercise (Cappelli, Verini-Supplizi, Capomaccio and Silvestrelli unpublished results). Equus caballus (ECA) IL8 full length cDNA, isolated from peripheral blood lymphocytes of an endurance horse, was sequenced (GenBank accession number AY184956). The mRNA sequence is 1089 nt in length and contains a 306 nt region that putatively codes for a 101 amino acid protein. In the framework of studying the modulation of gene expression profi les in racing horses, we report here the chromosomal location of ECA IL8 . This result adds a new type I marker to the FISH map of the horse.