DNA sequence and physical mapping of the canine transglutaminase 1 gene

Abstract

The transglutaminase 1 gene (TGM1) encodes an enzyme necessary for cross-linking the structural proteins that form the cornified envelope, an essential component of the outermost layer of the skin, the stratum corneum. Reported here is the complete coding region of canine TGM1, its chromosome localization, and its map position in the integrated canine linkage-radiation hybrid map. Canine TGM1 consists of 2,448 nucleotides distributed over 15 exons. The nucleotide sequence has 90% identity to human TGM1. The deduced canine TGM1 protein is 816 amino acids long and is 92% identical to human TGM1. Using fluorescence in situ hybridization, we localized canine TGM1 to dog (Canis familiaris) chromosome 8 (CFA 8q). Canine TGM1 localized to CFA 8 on the integrated linkage-radiation hybrid map in the interval FH2149–MYH7. Characterizing the coding region of canine TGM1 is a first step in examining the role of this enzyme in normal and defective cornification in the dog.

Clinical, histopathological and genetic data of ichthyosis in the golden retriever: a prospective study

“…The molecular characteristics of ichthyoses are beginning to be elucidated (Credille and others 2001, Barnhart and others 2004, Credille and others 2005). Ichthyosis in Norfolk terriers is epidermolytic and associated to a defect in keratin 10 because of a splice site mutation (Barnhart and others 2004, Credille and others 2005); this type of ichthyosis may also exist in other breeds, such as cavalier King Charles spaniels, despite ultrastructural features of the disease in this particular breed being similar to the human form, ichthyosis hystrix of Curth and Macklin (Alhaidari and others 1994).…”

The Clinical and Morphologic Features of Nonepidermolytic Ichthyosis in the Golden Retriever

“…Because canine microsatellite markers near canine TGM1 are available, as is the coding sequence, molecular biology studies could potentially rule out defects in TGM1 as a cause of the disease in Golden Retrievers. 13 Ultrastructural analysis may reveal specific structural abnormalities diagnostic of some heritable ichthyoses and blistering genodermatoses. For example, ichthyosis vulgaris is characterized by few intact or complete absence of keratohyalin granules in the granular layer, which is correlated with loss of profilaggrin or filaggrin.…”

Building Comparative Maps Using 1.5x Sequence Coverage: Human Chromosome 1p and the Canine Genome

“…The probability of a specific 100-base fragment of the genome occurring entirely within a single sequence read of 576 bases is only 0.58. However, most human genes appear to be composed of at least 4 exons (Venter et al 2001), and given the known similarity in gene structure between humans and canids (see, e.g., Szabo et al 1996;Credille et al 2001;Haworth et al 2001), the same is likely to be true for dog. Consequently, the probability that at least one 100-base exon fragment from a gene is contained within the genomic sequence data can be estimated as >0.95.…”