International Mammalian Genome Society

The 14th International Mouse Genome Conference (2000)

Table of Contents * Genes, Physical Mapping and Sequencing * Gene Identification * Bioinformatics * Common Resources * RIKEN Session * Functional Genomics * Complex Traits * Mutagenesis * Developmental Genetics and Differentiation * Verne Chapman Memorial Lecture I and II

I18. A Modifier Gene of the Mouse Ribosomal Mutant Tail-short (Ts) is Linked to the Causative Gene

Junko Ishijima¹, Kunihiko Shimizu², Yoshiaki Kikkawa³, Hiromichi Yonekawa³, Toshihiko Shiroishi¹.
¹Mammalian Genetics Laboratory, National Institute of Genetics, Mishima, Japan;
²Department of Pediatric Dentistry, Nihon University School of Dentistry at Matsudo, Chiba, Japan;
³Department of Laboratory Experimental Animal Science, The Tokyo Metropolitan Institute for medical Science, Tokyo, Japan

A mouse skeletal mutation, Tail-short (Ts), exhibits variable types of malformation, including kinky tail, vertebral homeotic transformations, developmental retardation and neural tube defects. We have identified that the causative gene of Ts mutation is Rpl38 gene that encodes an 8.1kD small component of ribosomal 60S large subunit. The phenotype of Ts mutation varies depending on the mouse strain to which the mutant is crossed. It ranges from almost no-phenotype except for the vertebrate homeotic transformation to dominant full lethality with severe neural tube defect. Detailed linkage analysis indicated that a single chromosomal region is responsible for the difference. A gene(s) that modifies the Ts phenotype was mapped to a 1.8cM interval between two microsatellite markers, D11Mit167 and D11Mit293, including the Ts locus itself in the chromosome 11. Because we found no variation in the cDNA sequence and expression level of Rpl38 mRNA among several strains, which show different phenotypes in the cross with Ts mutant, Rpl38 gene could be excluded as the gene responsible for the modification of the Ts phenotype. Thus, the Ts modifier gene(s) is possibly located in the region closely linked to the Ts causative gene, but a distinct region from Rpl38 gene. The modifier gene is expected to interact with Rpl38 gene, and is likely involved in the function of translational machinery of ribosome.