Genetic variability of the equine casein genes.
The casein genes are known to be highly variable in typical dairy species, such as cattle and goat, but the knowledge about equine casein genes is limited. Nevertheless, mare milk production and consumption is gaining importance because of its high nutritive value, use in naturopathy, and hypoallergenic properties with respect to cow milk protein allergies. In the current study, the open reading frames of the 4 casein genes CSN1S1 (αS1-casein), CSN2 (β-casein), CSN1S2 (αS2-casein), and CSN3 (κ-casein) were resequenced in 253 horses of 14 breeds. The analysis revealed 21 nonsynonymous nucleotide exchanges, as well as 11 synonymous nucleotide exchanges, leading to a total of 31 putative protein isoforms predicted at the DNA level, 26 of which considered novel. Although the majority of the alleles need to be confirmed at the transcript and protein level, a preliminary nomenclature was established for the equine casein alleles.
Institute of Animal Breeding and Husbandry, Christian-Albrechts-University Kiel, D-24098 Kiel, Germany.
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J
Brinkmann
Institute of Genetics, University of Bern, CH-3001 Bern, Switzerland; Swiss Competence Center of Animal Breeding and Genetics, University of Bern, Bern University of Applied Sciences HAFL and Agroscope, CH-3001 Bern, Switzerland.
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V
Jagannathan
Institute of Genetics, University of Bern, CH-3001 Bern, Switzerland; Swiss Competence Center of Animal Breeding and Genetics, University of Bern, Bern University of Applied Sciences HAFL and Agroscope, CH-3001 Bern, Switzerland.
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C
Drögemüller
Swiss Competence Center of Animal Breeding and Genetics, University of Bern, Bern University of Applied Sciences HAFL and Agroscope, CH-3001 Bern, Switzerland; Agroscope, Swiss National Stud Farm, CH-1580 Avenches, Switzerland.
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S
Rieder
Institute of Genetics, University of Bern, CH-3001 Bern, Switzerland; Swiss Competence Center of Animal Breeding and Genetics, University of Bern, Bern University of Applied Sciences HAFL and Agroscope, CH-3001 Bern, Switzerland.
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T
Leeb
Institute of Animal Breeding and Husbandry, Christian-Albrechts-University Kiel, D-24098 Kiel, Germany.
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G
Thaller
Institute of Animal Breeding and Husbandry, Christian-Albrechts-University Kiel, D-24098 Kiel, Germany. Electronic address: jtetens@tierzucht.uni-kiel.de.
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J
Tetens
D000483:Alleles; D000818:Animals; D001947:Breeding; D002364:Caseins / Q000032:analysis / Q000235:genetics*; D004247:DNA; D005260:Female; D014644:Genetic Variation; D006736:Horses / Q000235:genetics*; D008892:Milk / Q000737:chemistry; D016366:Open Reading Frames / Q000235:genetics
D002364:Caseins; D004247:DNA
caseins; genetic variability; isoforms; mare milk