Biomaterial Database

New mouse models of congenital anorectal malformations. 2000

S G Kimmel, and R Mo, and C C Hui, and P C Kim

The Hospital for Sick Children, Research Institute, Infection, Immunity, Injury, and Repair, University of Toronto, Department of Surgery, Ontario, Canada.

OBJECTIVE The genetic, embryological, and pathogenetic aspects of hindgut development remain poorly understood. Recently, the morphogenetic pathway involving the Sonic hedgehog (Shh) gene has been shown essential to the normal development of many midaxial organs, including the foregut. This study reports genetically based murine models of congenital anorectal malformations (CAM) involving the Shh-responsive transcription factors, Gli2 and Gli3. Its purpose is to show the necessity of these 2 factors to normal hindgut development. METHODS Gli2-/- mutants were generated by a targeted deletion. Gli3-/- mutants are spontaneous mutants involving the Gli3 gene. Gli2-/- Gli3+/- mutants were generated by intercrossing double heterozygotes. Whole-mount midsagittal sections of the embryos were analyzed on embryonic days (E) 11.5 and E13.5. RESULTS Gli3-/- mutants had anal stenosis and ectopic anus, and Gli2-/- mutants showed imperforate anus and rectourethral fistula. Gli2-/- Gli3+/- mutants had a cloacal abnormality. CONCLUSIONS The phenotypic abnormalities observed in these mutant mice are identical to the spectrum of human CAM. The severity of the phenotype appears to reflect the gene dose. Gli2 and Gli3 play an important role in the normal development of murine hindgut. The results of this study provide, for the first time, a molecular basis for CAM.

UI	MeSH Term	Description	Entries
D008817	Mice, Mutant Strains	Mice bearing mutant genes which are phenotypically expressed in the animals.	Mouse, Mutant Strain,Mutant Mouse Strain,Mutant Strain of Mouse,Mutant Strains of Mice,Mice Mutant Strain,Mice Mutant Strains,Mouse Mutant Strain,Mouse Mutant Strains,Mouse Strain, Mutant,Mouse Strains, Mutant,Mutant Mouse Strains,Mutant Strain Mouse,Mutant Strains Mice,Strain Mouse, Mutant,Strain, Mutant Mouse,Strains Mice, Mutant,Strains, Mutant Mouse
D010641	Phenotype	The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.	Phenotypes
D012007	Rectum	The distal segment of the LARGE INTESTINE, between the SIGMOID COLON and the ANAL CANAL.	Rectums
D002455	Cell Division	The fission of a CELL. It includes CYTOKINESIS, when the CYTOPLASM of a cell is divided, and CELL NUCLEUS DIVISION.	M Phase,Cell Division Phase,Cell Divisions,Division Phase, Cell,Division, Cell,Divisions, Cell,M Phases,Phase, Cell Division,Phase, M,Phases, M
D002988	Cloaca	A dilated cavity extended caudally from the hindgut. In adult birds, reptiles, amphibians, and many fishes but few mammals, cloaca is a common chamber into which the digestive, urinary and reproductive tracts discharge their contents. In most mammals, cloaca gives rise to LARGE INTESTINE; URINARY BLADDER; and GENITALIA.	Cloacas
D004195	Disease Models, Animal	Naturally-occurring or experimentally-induced animal diseases with pathological processes analogous to human diseases.	Animal Disease Model,Animal Disease Models,Disease Model, Animal
D004707	Endoderm	The inner of the three germ layers of an embryo.	Definitive Endoderm,Definitive Endoderms,Endoderm, Definitive,Endoderms
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001003	Anal Canal	The terminal segment of the LARGE INTESTINE, beginning from the ampulla of the RECTUM and ending at the anus.	Anal Gland, Human,Anal Sphincter,Anus,Anal Gland,Anal Glands, Human,Detrusor External Sphincter,External Anal Sphincter,Internal Anal Sphincter,Anal Sphincter, External,Anal Sphincter, Internal,Anal Sphincters,Detrusor External Sphincters,External Anal Sphincters,Human Anal Gland,Human Anal Glands,Internal Anal Sphincters,Sphincter, Anal,Sphincter, Detrusor External,Sphincter, External Anal,Sphincter, Internal Anal,Sphincters, Anal
D014157	Transcription Factors	Endogenous substances, usually proteins, which are effective in the initiation, stimulation, or termination of the genetic transcription process.	Transcription Factor,Factor, Transcription,Factors, Transcription