BOR - Papers in Press, published online ahead of print
January 8, 2003.
Biol Reprod 2003, 10.1095/biolreprod.102.008466
BIOLOGY OF REPRODUCTION 68, 19751981 (2003)
DOI: 10.1095/biolreprod.102.008466
© 2003 by the Society for the Study of Reproduction, Inc.
INSL3 Ligand-Receptor System in the Equine Testis1
Thomas Klonisch2,3,
Klaus Steger5,
Astrid Kehlen4,
William R. Allen6,
Christine Froehlich3,
Johannes Kauffold7,
Martin Bergmann5, and
Sabine Hombach-Klonisch3
Departments of Anatomy and Cell Biology3
Immunology,4 Martin Luther University Halle-Wittenberg, Faculty of Medicine, Grosse Steinstrasse 52, D-06097 Halle (Saale), Germany
Institute of Veterinary Anatomy,5 Justus Liebig University Giessen, D-35392 Giessen, Germany
Department of Clinical Veterinary Medicine,6 Equine Fertility Unit, University of Cambridge, Newmarket, Suffolk, CB8 9BH, United Kingdom
Large Animal Clinic for Theriogenology and Ambulatory Services,7 Faculty of Veterinary Medicine, University of Leipzig, D-04103 Leipzig, Germany
We employed molecular and immunological techniques to investigate the expression of INSL3, a member of the insulin-like superfamily, in prepubertal testis, postpubertal testes exhibiting normal and disturbed spermatogenesis, and cryptorchid testes of male horses. In addition, the partial cDNA coding sequences of the equine homologue of the human relaxin/INSL3-receptor Lgr8 were determined. Nonradioactive in-situ hybridization with a cRNA probe for equine Insl3 and immunohistochemistry with a specific rabbit INSL3 antiserum localized Insl3 transcripts and immunoreactive INSL3 ligand to Leydig cells in all types of testes investigated. Quantitative polymerase chain reaction analysis revealed a down-regulation of Insl3 and an up-regulation of the relaxin/INSL3-receptor expression in unilateral cryptorchid versus descended testes. Western blot analysis of protein extracts from adult normal and cryptorchid testes and prepubertal testes showed a single immunoreactive band at 14.5 kDa, which correlates with the predicted size of equine proINSL3. Densitometric analysis of Western blot data of adult normal testes revealed significantly stronger expression of immunoreactive proINSL3 as compared to extracts derived from cryptorchid or prepubertal testes. Thus, decreased expression of immunoreactive INSL3 in cryptorchid and prepubertal equine testis is transcriptionally regulated. The detection of transcripts for equine Lgr8 in the testis has identified the testis as a potential target of INSL3.
1 Funded in part by Fonds der Chemischen Industrie (FCI) and by the Deutsche Forschungsgemeinschaft (KL 1249/5-1 and 5-2; HO 2319/3-1).
2 Correspondence: Thomas Klonisch, Department of Anatomy and Cell Biology, Medical Faculty of the Martin Luther University Halle-Wittenberg, Grosse Steinstrasse 52, D-06097 Halle/Saale, Germany. FAX: 49 0 345 557 1700; thomas.klonisch{at}medizin.uni-halle.de
Copyright © 2003 by the Society for the Study of Reproduction.