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External and Skeletal Observations on a New Lethal Mutant of the Rat: Congenital Osteochondrodysplasia with Systemic Subcutaneous Edema
Author(s) -
SUZUKI Katsushi,
KIKUKAWA Keiichiro,
IMAMICHI Tomonori
Publication year - 1987
Publication title -
congenital anomalies
Language(s) - English
Resource type - Journals
eISSN - 1741-4520
pISSN - 0914-3505
DOI - 10.1111/j.1741-4520.1987.tb00696.x
Subject(s) - edema , anatomy , osteochondrodysplasia , medicine , skull , mutant , ossification , biology , pathology , genetics , gene
Malformed rat newborns showing severe subcutaneous edema were frequently found dead in our Wistar‐Imamichi rat colony. Their family record suggested that this malformation would be an inherited disorder. Experimental crosses of the phenotypically normal litter‐mates revealed that this malformation was a new lethal mutant of the rat, following a single autosomal recessive inheritance. External features and skeletal anomalies of the mutant were carefully checked and compared to those of the phenotypically normal litter‐mates. The comparison revealed that (1) this mutant has a characteristic external appearance that includes shortening of the head, trunk, tail and extremities, systemic subcutaneous edema, protruding of the tongue and cleft palate, (2) the axial bones and appendices are shortened and deformed severely and (3) ossification status of the newborn is delayed in digital bones and advanced in the vertebral centra and arches, stemebrae, choracoid process and talus. Observation of the parturition showed that this mutant is born alive but die shortly after birth because of breathing insufficiency. Based on these observations, this mutant was diagnosed as congenital osteochondrodysplasia with systemic subcutaneous edema (ocd for the gene symbol). The mode of inheritance and the similarities to some genetical disorders of other species, including human, are discussed.