Department of Preclinical Veterinary Sciences, Faculty of Veterinary Medicine, University Putra Malaysia, Serdang, Selangor, Malaysia A Lectin Histochemical Study on the Testis of the Babirusa, Babyroussa babyrussa (Suidae) S. Agungpriyono 1,2 *, M. Kurohmaru 3 , W. E. Prasetyaningtyas 2 , L. Kaspe 4 , K. Y. G. Leus 5 , M. Sasaki 6 , N. Kitamura 6 , J. Yamada 6 and A. A. Macdonald 7 Addresses of authors: 1 Department of Preclinical Veterinary Sciences, University Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia; 2 Department of Veterinary Anatomy, The University of Tokyo, Tokyo 113-8657, Japan; 3 Department of Anatomy, Physiology and Pharmacology, Bogor Agricultural University, Bogor 16680, Indonesia; 4 Surabaya Zoo, Jl. Setail, Surabaya, Indonesia; 5 Centre for Research and Conservation, Royal Zoological Society of Antwerp, B-2018 Antwerp Belgium; 6 Department of Veterinary Basic Science, Obihiro University of Agriculture and Veterinary Medicine, Obihiro 080-8555, Japan; 7 Division of Veterinary Biomedical Sciences, The Royal (Dick) School of Veterinary Studies, The University of Edinburgh, Edinburgh EH9 1QH, UK; *Corresponding author: Tel.: +60 3 8946 8260; fax: +60 3 8946 8333; e-mail: srihadi@vet. upm.edu.my With 2 figures and 3 tables Received October 2006; accepted for publication November 2006 Summary The distribution of lectin bindings in the testis of babirusa, Babyrousa babyrussa (Suidae) was studied histochemically using 10 biotinylated lectins, Peanut agglutinin (PNA), Ricinus communis agglutinin (RCA I), Dolichos biflorus agglutinin (DBA), Vicia villosa agglutinin (VVA), Soybean agglutinin (SBA), Wheat germ agglutinin (WGA), Lens culinaris agglu- tinin (LCA), Pisum sativum agglutinin (PSA), Concanavalin A(Con A) and Ulex europaeus agglutinin (UEA I). Nine of 10 lectins showed a variety of staining patterns in the seminifer- ous epithelium and interstitial cells. The acrosome of Golgi-, cap- and acrosome-phase spermatids displayed various PNA, RCA I, VVA, SBA and WGA bindings, indicating the pres- ence of glycoconjugates with d-galactose, N-acetyl-d-galacto- samine and N-acetyl-d-glucosamine sugar residues respectively. No affinity was detected in the acrosome of late spermatids. LCA, PSA and Con A which have affinity for d-mannose and d-glucose sugar residues were positive in the cytoplasm of spermatids and spermatocytes. DBA was positive only in spermatogonia. In addition to DBA, positive binding in spermatogonia was found for VVA, WGA and Con A, suggesting the distribution of glycoconjugates with N-acetyl- d-galactosamine, N-acetyl-d-glucosamine, d-mannose and d-glucose sugar residues. Sertoli cells were stained intensely with RCA I, WGA and Con A. In Leydig cells, RCA I and Con A were strongly positive, while WGA, LCA and PSA reactions were weak to moderate. The present findings showed that the distribution pattern of lectin binding in the testis of babirusa is somewhat different from that of pig or other mammals reported previously. Introduction Glycoconjugates play important roles in cell differentiation and maturation (Damjanov, 1987), cell recognition and adhesion (Sharon and Lis, 1989) and cell to cell interaction (Wassarman, 1989). The distribution of glycoconjugates in various tissues has been widely studied using lectin histo- chemistry because of the specific affinity of lectins to sugar residues (Spicer, 1993). The distribution of lectin binding in the testis has been studied in the human (Lee and Damjanov, 1985; Malmi et al., 1987; Malmi and So¨der- stro¨m, 1987; Wollina et al., 1989; Arenas et al., 1998), laboratory rodents (So¨derstro¨m et al., 1984; Arya and Vanha-Perttula, 1986; Martı´nez-Mena´ rgues et al., 1992; Martı´nez-Mena´rguez et al., 1993) and farm animals (Arya and Vanha-Perttula, 1985; Kurohmaru et al., 1991; Calvo et al., 2000; Verini-Supplizi et al., 2000; Pinart et al., 2001). The studies show that extensive modification of glycoconju- gates occur during spermatogenesis as expressed by differ- ences in the binding patterns of their sugar residues to lectins; these changes differ among animal species. The lectin-binding pattern in the testis has been studied in domestic pig (Calvo et al., 2000; Pinart et al., 2001). However, no such study has been reported in the babirusa, a very different member of the Family Suidae (pigs). Babirusa (Babyrousa babyrussa) are distributed only on Indonesian Island of Sulawesi and its surrounding islands (Groves, 1980). The population of babirusa in the wild is threatened by hunting and habitat destruction. Because of its limited distribution and declining number, the babirusa is considered to be endangered by the International Union for Conservation of Nature and Natural Resources (IUCN) and is listed in the appendices I of Convention on International Trade in Endangered Species (CITES). The Indonesian gov- ernment has given the animal the second most important priority for conservation after Indonesian rhinos. Among three living subspecies of the genus Babyrousa, B. babyrussa celebensis is the only subspecies currently held in zoological collections around the world. The materials for the present study were obtained from this subspecies. Several recent studies have reported the behaviour of babirusa (Leus et al., 1992; Patry et al., 1995; Leus and Vercammen, 1996), and current knowledge of reproduction was reviewed by Macdonald (2000). This found no study describing the reproductive function of male babirusa. In this study, we observed the distribution of lectin binding in the testis of the animal. Ó 2007 The Authors. Journal compilation Ó 2007 Blackwell Verlag www.blackwell-synergy.com Anat. Histol. Embryol. doi: 10.1111/j.1439-0264.2007.00778.x ISSN 0340–2096