Histological Analysis of Endocrine Disruptive Effects in Small Laboratory Fish

Daniel R. Dietrich, PhD , is a Professor and Head of the Human and Environmental Toxicology Group, Faculty of Sciences of the University of Konstanz, Konstanz, Germany. Heiko O. Krieger, MSc , is a scientific research assistant and PhD student in the Human and Environmental Toxicology Group, Faculty of Sciences of the University of Konstanz, Konstanz, Germany.

Preface. Acknowledgments. Contributing Authors. 1 Introduction. References. 2 Fish Species of Interest. 2.1 Fathead Minnow (Pimephales promelas). 2.2 Medaka (Oryzias latipes). 2.3 Zebrafish (Danio rerio). 2.4 Other Fish Species. References. 3 Sexual Determination, Differentiation, and Gonadal Development. 3.1 Primordial Germ Cells in the Primordial (Primary) Gonad. 3.2 Reproductive Strategies. 3.3 Differentiation of the Primordial Gonad into Ovary or Testis. 3.4 Gonadal Duct Formation. 3.5 Endocrinology: Influence on Gonadogenesis. 3.6 Critical Period of Sexual Differentiation in Developing Fish. 3.7 Bi-Potentiality of Germ Cells in Adult Fish. References. 4 Female Gonad Anatomy and Morphology. 4.1 Gonadogenesis: Ovary. 4.2 Hypothalamic-Pituitary-Ovarian Axis. 4.3 Cellular Structure of the Ovary. References. 5 Male Gonad Anatomy and Morphology. 5.1 Gonadogenesis: Testes. References. 6 Endocrine-Disrupting Compounds. 6.1 Individual Effects. 6.2 Effects Associated with Exposure to Specific Compounds or Compound Classes. 6.3 Population Effects. References. 7 Determination of Effects of Exogenous Hormones and Endocrine-like Active Compounds. 7.1 Histological Processing: Microdissection versus Whole-Fish Sectioning. 7.2 Optimal Tissue Preparation and Histological Techniques. 7.3 Plane of Gonad Sectioning for Optimal Organ Representation. References. 8 Evaluation of Effects in Fish Gonads. 8.1 Qualitative (Semiquantitative) versus Quantitative Evaluation. 8.2 Gonadal Staging in the Testis. 8.3 Gonadal Staging in the Ovary . 8.4 Qualitative Assessment of Histopathological Changes. References. 9 Experimental Design and Statistics. 9.1 Basic Considerations in Experimental Design. 9.2 Variables to be Determined and Their Inherent Biological and Mathematical Characteristics. 9.3 Prerequisite Statistical Concepts. 9.4 Statistical Tests and Testing Situations Encountered Routinely. References. 10 Conclusions. References. Appendix: Fish Preparation and Microdissection of Organs. A.1 Fish Preparation. A.2 Microdissection of Organs. A.3 Tissue Fixation. A.4 Embedding. A.5 Tissue Sectioning. A.6 Sample Mounting. A.7 Tissue Slide Staining. A.8 Final Processing. A.9 Examples. A.10 Summary. References. Index.