195 ©2003, European Journal of Histochemistry Defensins are a family of host defence peptides that play an important role in the innate immunity of mammalian and avian species. In humans, four β-defensins have been iso- lated so far, corresponding to the products of the genes DEFB1 (h-BD1, GenBank accession number NM_005218); DEFB4 (h-Bd2, NM_004942.2), DEFB103 (h-BD3, NM_018661); and DEFB104 (hBD4, NM_080389) map- ping on chromosome 8p23.22. We have localized β- defensin genes on metaphasic chromosomes of great apes and several non-human primate species to determine their physical mapping. Using fluorescent in situ hybridization and BAC probes containing the four β-defensin genes, we have mapped the homologous regions to the β-defensin genes on chromosome 8p23-p.22 in non-human primates, while no signals were detected on prosimians chromosomes. Key words: Innate immunity, molecular evolution, FISH, homology. Correspondence: Sergio Crovella, Reproduction and Development Science Department, University of Trieste, via dell'Istria 65/1, 34137 Trieste, Italy. Phone: international +39.040.3785538. Fax: international +39.040.3785540. E-mail: crovella@burlo.trieste.it Paper accepted on January 26, 2004 European Journal of Histochemistry 2004; vol. 48 issue 2 [Apr-Jun]: 195-200 Localization of β-defensin genes in non human primates M. Ventura, 1 M. Boniotto, 2 M. Pazienza, 1 V. Palumbo, 2 M.F. Cardone, 1 M. Rocchi, 1 A. Tossi, 4 A. Amoroso, 2,3 S. Crovella 2,3 1 University of Bari, DAPEG Genetics Section, Bari; 2 University of Trieste, Reproduction and Development Science Department, Trieste; 3 Genetic Service, Children Hospital Burlo Garofolo, Trieste; 4 University of Trieste, Department of Biochemistry, Biophysics and Chemistry of Macromolecules, Trieste, Italy I n humans, four β-defensins have been isolated and well characterized so far: i) DEFB1 (h- BD1, GenBank accession number NM_005218) is constitutively expressed in kidney tubules and at lower levels in the pancreas, lungs and genitourinary tract (Bensch et al. 1995; Schonwetter et al. 1995; Diamond et al.1996; Zhao et al. 1996; Goldman et al. 1997); ii) DEFB4 (h- Bd2, NM_004942.2) is primarily induced in skin and other epithelia during inflamation (Harder et al. 1997b; Hiratsuka et al. 1998; Liu et al. 1998; Mathews et al. 1999); iii) DEFB103 (h-BD3, NM_018661) is secreted by keratinocytes and epithelial cells of the respiratory tract after inflam- matory stimuli or after contact with Gram-negative or Gram-positive bacteria (Harder et al. 1997a) and iv) DEFB104 (hBD4, NM_080389), whose expression seems to be mainly in the in testis, stom- ach, uterus, neutrophils, thyroid, lung and kidney (Garcia et al. 2001). A lot of studies indicate that these molecules could play an important role in host defence, having both a direct, broad spectrum but salt sensitive antimicrobial activity (Lehrer and Ganz, 2002), and also playing a role in mobilizing other components of innate or adaptive immunity (Yang et al.,2002). Twenty eight other putative β-defensin genes have been identified in the human genome, using a bioin- formatic technique, based primarily on the 6-cys- teine motif present in these molecules (Schutte et al., 2002). Schutte et al. (2002) discovered five conserved b- defensin gene clusters in human and analogous clus- ters in mouse, using a computational search strate- gy: they identified the putative second exons of 28 new human and 43 new mouse β-defensin genes organized in five syntenic chromosomal regions. Within each cluster, the similarity of gene sequences and organization suggested each cluster pair arose from a common ancestor and was retained because of conserved functions. Other authors (Semple et LETTER TO THE EDITOR