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

Dr. Zdenek Trachtulec
Institute Molec.Genetics, Acad. Sci.
Videnska 1083
Prague
142 20
Czech Republic

Co-Authors: Vlcek C., Paces V., And Forejt J.
Institutions: Institute Molec. Genetics, Acad.Sci.

During genomic sequencing of the Hybrid sterility 1 (Hst1) region on mouse chromosome 17, we found sequences putatively encoding  CRAB, PR and C2H2 domains. Subsequent RT-PCR and RACE analysis has revealed two types of transcripts. The longer mRNA encodes all three domains. The shorter transcript carries only the CRAB domain and it is truncated by an alternative termination exon. The alternative exon is composed solely of a  B1 short interspersed repeat element (SINE) in the orientation  opposite to the CRAB-domain gene. The B1 element provides both the 3'-splicing site and the polyadenylation signal. Several other examples of alternative splicing due to mouse SINE repeats have been revealed in public databases. The number of the human (and likely also of the mouse) genes is believed to be only about twice the number of the genes in invertebrates (Drosophila or C. elegans). It has been suggested  that an additional complexity in mammalian proteins is created by alternative splicing. From our data, together with the previously  described insertions of Alu-carrying exons into the coding regions  of human genes, we conclude that SINE transpositions can play a significant  role in increasing the complexity of the mammalian proteomes.