The development of three manifestations of the short ear gene in the mouse

✍ Scribed by Earl L. Green; Margaret Creighton Green

• Publisher: John Wiley and Sons
• Year: 1942
• Tongue: English
• Weight: 921 KB
• Volume: 70
• Category: Article
• ISSN: 0362-2525
• DOI: 10.1002/jmor.1050700102

✦ Synopsis

FIVE TEXT I'IGVXES AN11 THRICE PLATES (TTVEXTY-FJGHT FIGURES)

Mature mice homozygous for the short car gene (seauto-soma1 recessive) differ from normal mice in a marked recluction in size of the external scaphal portion of the ear (Lynch, '21, figs. 6, 7). The se gene appears also to decrease head aiid body size (Snell, '31; Castle et al., '36; Law, '38), gossil~lp to cause a neuromuscnlar kirikiiiess of the tail ( h e l l , '31), a i d to cause a malformatioii of the xipliisteriium (Green and -IlcNutt, '41). Possihly other effects of this gene exist but they liave not as yet been thoroughly investigated by genetic methods. Xothing has been known of the developmental processes disturbed by this gene and leading to the visible manifestations in ear, xiphisternum, and body size. Since gene pleiotropy is a central problem in studies of developmental genetics, the results of an attempt to discover the time and man~ipr of action of sc upon these developmental processes will be descrihed.

XATERIALS MSD METIIODS

Mice of known genotype, Re or s c , were ohtained a t daily iiitervals from 10 days of gestation to 8 d a y after birth and at irregular intervals thercafter, from one inbred normal strain, two inbred short ear strains, a i d one hackcross generation (table l). The xiphisteunums of the two short car This work was done while holder of a Corinna Borden Keen Research Pellomship of Brown Univrrsitj in residenee at The University of Chicago. We nre deeply indebted to Prof. Sewall Wright for laborxtory farilities and encouragempnt tliraughout the r n m e of the work.