Читать книгу Pathology of Genetically Engineered and Other Mutant Mice - Группа авторов - Страница 92

Developmental phenotypes in embryonic and neonatal mice may be evaluated readily by comparative pathologists using routine macroscopic (gross observations and measurements of whole‐animal or organ dimensions, volumes, or weights) and microscopic (light microscopy) techniques. If available, interpretation of such conventional endpoints is aided substantially by integration with other classes of data such as digital files acquired by noninvasive imaging or molecular expression profiles obtained from homogenized tissue samples or specially stained tissue sections. Lesions in embryos (and/or placentas) and neonates exhibit different patterns depending on when during development damage occurs in the conceptus. Genetic mutations, infectious agents, and toxicants all can adversely impact developing tissues, and can elicit comparable patterns of cell and tissue damage. The rapid anatomic and biochemical evolution in both space and time that takes place throughout the course of development ensures that the analysis of a potential lethal phenotype usually will be a complicated endeavor, requiring both patience and skill in designing the analytical strategy. Successful projects require an initial determination of the time of death followed by identification and detailed characterization of anatomic changes, functional abnormalities, and their molecular bases. Investigators should be prepared to acknowledge that a certain number of projects ultimately may fail to determine a cause for the developmental lethality.