Breeding Physiology

Muscle ESTs II: Cloning, Sequencing, and Mapping the Pig Gene for the Intermediate Filament Protein Desmin

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Abstract

The results of sequencing large numbers of random cDNAs in the human genome project has clearly shown value in gene discovery and mapping. We previously demonstrated a simple approach to rapidly identify musclespecific pig cDNAs for sequencing by strong hybridization to muscle cDNA probes. In this report, we sequenced additional muscle cDNAs, emphasizing clones that were not strongly expressed in muscle. Fewer clones matched known muscle-specific genes in the pig or other species, indicating selection by hybridization is most accurate for strongly hybridizing clones showing weak signals with non-muscle probes. Some muscle-specific clones, however, also were identified by sequencing the weakly hybridizing class of cDNAs. One of these was M239, encoding muscle-specific desmin, which is an intermediate filament protein involved in holding muscle fibers together. As desmin may be an interesting candidate gene for muscle tenderness, the desmin gene (DES) was fully sequenced and mapped both physically and genetically. Pig desmin is highly conserved, being more than 97% identical at the amino acid level to human and mouse desmin. Linkage of DES was observed for three loci already mapped to pig chromosome 15 (SSC15), and physical mapping placed DES on SSC15q23-26. This mapping information will be useful in further studies on the role of DES in muscle biology and muscle tenderness traits.

Keywords: ASL R1576

How to Cite:

Tuggle, C. K., Smith, B., Sanchez-Serrano, I., Ernst, C. & Marklund, L., (1999) “Muscle ESTs II: Cloning, Sequencing, and Mapping the Pig Gene for the Intermediate Filament Protein Desmin”, Iowa State University Animal Industry Report 1(1).