International Mammalian Genome Society

The 15th International Mouse Genome Conference (2001)

Table of Contents * Complex Genetics * Developmental Genetics * Gene Annotation * Gene Discovery * Genome Sequencing * Functional Genomics * Mutagenesis * Presentations * Verne Chapman Memorial Lecture

Helena Motaln
University of Ljubljana
Biotechnical Faculty
Zootechnical Department
Groblje 3
1230 Domzale
Slovenia

Co-Authors: 1)Freking B.A., 2)Medrano J.F., 3)Horvat S.
Institutions: 1)Clay Center, Meat Animal Research Center, 2)University of California, Department of Animal Science, 3)University of Ljubljana, Biotechnical Faculty, Zootechnical Department

The high growth (hg) mutation causes a 30-50% increase in growth and comprises a deletion of 500-kb containing Vespr, Raidd and Socs2. We have recently shown that the Socs2 deficiency is causal for the increased growth phenotype. To further characterize the hg region and identify possible new transcripts, we employed exon trapping and comparative mapping. Out of 114 exon traps isolated, some were excluded due to repetitive or vector sequences and exons of the known genes. Primers were successfully designed for 57 exon traps out of which 41 gave a positive RT-PCR signal in the control strain. 28 exon traps were RT-PCR-negative in the hg mutant confirming that they map within deletion. These exon traps might belong to new transcription units or to known genes, but to novel exons or alternative splice variants of these genes.Northern analysis has so far demonstrated expression of two exon traps that had expression pattern similar to Raidd, suggesting they could represent novel exons of Raidd. Using comparative mapping, 47 human expressed sequence tag clones (ESTs) were selected from the hg-homologous region in the human. Southern blots of restricted human ESTs were probed with BACs from the hg region identifying 10 ESTs with positive hybridization signals. These ESTs represent potential new candidate genes within the hg region. Using the above approaches it should be possible to find all transcripts and permit further functional characterization of the hg region.