title: Variation in salivary and pancreatic alpha-amylase genes in Italian horse breeds.
abstract: The dietary demand of the modern horse relies on high-cereal feeding and limited forage compared with natural grazing conditions, predisposing the horse to several important diseases. Salivary and pancreatic alpha-amylases (coded by AMY1 and AMY2 genes, respectively) play a crucial role in carbohydrate digestion in nonruminants, but little is known about these 2 genes in the horse. Aim of this work has been to distinguish genomic sequences of horse AMY1 and AMY2 genes and to analyze any polymorphisms in breeds historically characterized by marked differences in nutritional management. A single nucleotide polymorphism detection was performed and 7 novel single nucleotide polymorphisms were found. Three single nucleotide polymorphisms are in exons and were genotyped in 112 horses belonging to 6 breeds. One single nucleotide polymorphism in AMY1 gene distinguished Haflinger and the Italian native Murgese from the other breeds, whereas both the single nucleotide polymorphisms in AMY2 gene showed different allelic frequencies in Friesian compared with the other breeds. These differences are confirmed by quite high fixation index (Fst) values for these 2 nonsynonymous single nucleotide polymorphisms. These preliminary results highlight marked divergences in allele frequencies of AMY1 and AMY2 genes, involved in starch digestion, between horse breeds characterized by different histories of selection, thus providing first indications of possible relations between genetics and nutritional management.
authors.affiliation: the Dipartimento di Scienze Veterinarie e sanità pubblica, Università degli Studi di Milano, via Celoria 10, 20133 Milano, Italy.
authors.forename: Beatrice
authors.initials: B
authors.lastname: Coizet
authors.forename: Letizia
authors.initials: L
authors.lastname: Nicoloso
authors.forename: Donata
authors.initials: D
authors.lastname: Marletta
authors.forename: Alessandra
authors.initials: A
authors.lastname: Tamiozzo-Calligarich
authors.forename: Giulio
authors.initials: G
authors.lastname: Pagnacco
authors.forename: Paola
authors.initials: P
authors.lastname: Crepaldi
mesh_terms: D019943:Amino Acid Substitution; D000818:Animals; D001483:Base Sequence; D044822:Biodiversity; D004040:Dietary Carbohydrates; D004063:Digestion / Q000235:genetics*; D002523:Edible Grain / Q000737:chemistry; D014644:Genetic Variation; D060005:Genotyping Techniques; D006736:Horses / Q000145:classification / Q000235:genetics*; D007558:Italy; D055292:Pancreatic alpha-Amylases / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide; D055291:Salivary alpha-Amylases / Q000235:genetics*; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA
chemical_list: D004040:Dietary Carbohydrates; D055292:Pancreatic alpha-Amylases; D055291:Salivary alpha-Amylases
keywords: SNP; genetic diversity; starch digestion