Growth hormone gene polymorphism associated with selection for milk fat production in lines of cattle |
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Authors: | S Høj M Fredholm N J Larsen V H Nielsen |
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Institution: | National Committee on Danish Cattle Husbandry, Udkærsvej 15, DK-8200 Århus N, Denmark;The Royal Veterinary and Agricultural University, Department of Animal Production and Animal Health, Division of Animal Genetics, Bülowsvej 13, DK-1870 Frederiksberg C, Denmark;National Institute of Animal Science, Foulum Research Center, DK-8830 Tjele, Denmark |
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Abstract: | Summary Fifty-eight calves of both sexes from lines of Red Danish dairy breed selected for high ( n = 36) and low ( n = 22) milk fat production, and 32 heifers from lines of Norwegian Red dairy breed selected for high ( n = 16) and low ( n = 16) milk fat yield were typed for two previously reported restriction fragment length polymorphisms (RFLPs) in the growth hormone gene. The RFLPs are consistent with: (1) an insertion(I)/deletion(D) of approximately 0.9kb in the 3'-region of the growth hormone gene and (2) a polymorphic Msp I(+/−) site in the third intron. A traditional RFLP procedure was used for typing the I/D polymorphism and a polymerase chain reaction (PCR) procedure was developed for typing the Mspl polymorphism. Only the I-MspI(+) and D- Msp I(-) haplotypes were found. In the Red Danish lines the frequency of D- Msp I(-) haplo-type was 0.28 in high line and 0.05 in low line calves, this difference was significant ( P <0.01). The corresponding frequencies in the Norwegian Red lines were 0.09 in the high line and 0.0 in the low line. Attempts to screen for RFLPs in the growth hormone receptor gene and in the insulin-like growth factor-I gene were unsuccessful. |
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Keywords: | Growth hormone RFLP selected lines dairy cattle |
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