Stearoyl-coenzyme A desaturase gene polymorphism and milk fatty acid composition in Italian Holsteins.
Milk fatty acid composition is a parameter of great interest for evaluation of nutritional quality of milk. Stearoyl-CoA desaturase (SCD) is a key enzyme in mammary lipid metabolism because it is able to add a double bond in the cis delta9-position in a large spectrum of medium- and long-chain fatty acids. A polymorphism with 2 alleles (A and V) in the fifth exon of the SCD gene has been reported. The effect of SCD genotype on individual milk fatty acid composition and on cis-9 unsaturated/saturated fatty acid ratios of 297 Holstein Italian Friesian cows was investigated in this paper. The SCD genotypes were determined by using a single strand conformation polymorphism method. Relative frequencies of SCD genotypes were 27, 60, and 13% for AA, AV, and VV, respectively. Milk of AA cows had a greater content of cis-9 C18:1 and total monounsaturated fatty acids and a higher C14:1/C14 ratio than did milk of VV cows. The relative contribution of SCD genotype to variation of monounsaturated fatty acids, cis-9 C18:1, and cis-9 C14:1 was 5, 4, and 7.7%, respectively. No significant differences were detected between SCD genotypes in the milk content of cis-9, trans-11 C18:2. Results of the present work provide some indication of an association between SCD locus and the fatty acid profile in the examined sample of Italian Holsteins, thus suggesting a possible role of this gene in the genetic variation of milk nutritional properties.
Mele
M
M
Dipartimento di Agronomia e Gestione dell'Agroecosistema, University of Pisa, Italy. mmele@agr.unipi.it
Conte
G
G
Castiglioni
B
B
Chessa
S
S
Macciotta
N P P
NP
Serra
A
A
Buccioni
A
A
Pagnacco
G
G
Secchiari
P
P
D000818:Animals; D002417:Cattle / Q000235:genetics* / Q000378:metabolism; D004247:DNA / Q000032:analysis; D005223:Fats / Q000032:analysis; D005227:Fatty Acids / Q000032:analysis*; D005260:Female; D005838:Genotype; D007558:Italy; D008892:Milk / Q000737:chemistry*; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D018807:Polymorphism, Single-Stranded Conformational; D017422:Sequence Analysis, DNA; D013230:Stearoyl-CoA Desaturase / Q000235:genetics*
D005223:Fats; D005227:Fatty Acids; D004247:DNA; D013230:Stearoyl-CoA Desaturase