Genetic analysis and physiological responses of Brahman-influenced bulls to an immune challenge.

摘要

Previously, we demonstrated that single nucleotide polymorphisms (SNP) in upstream elements of bovine heat shock protein (HSP) gene were related to cow endocrine and reproductive responses. Angus-sired Brahman-influenced bulls (n=19) were developed on common bermudagrass (Cynodon dactylon (L.) Pers.) pastures over seeded with Elbon rye (Senile cereale L.) for 160 d post weaning. At weaning and d 160 blood samples were collected. Weight and SC were measured monthly. Blood cell differentials, and serum concentrations of cortisol, prolactin, testosterone , and insulin like growth factor-1 GF-1 factor were determined. Bulls were genotyped based on our previously published HSP primers. For the first study bulls were identified by three different genotypes: (1) bulls with a deletion at nucleotide 895 in HSP70 promoter region (HSP70D) (n=4), (2) bulls with no deletion in HSP70 promoter region (HSP7ON) (n=6), and (3) bulls with any single nucleotide polymorphisim (SNP) in HSP70 promoter region (HSP70Y) (n=9). Bulls containing a non deletion SNP (HSP70Y) weighed less (p 0.05) than bulls with no SNPs (HSP7ON) or deletion SNPs (HSP70D), however, HSP7OD and HSP7ON bulls body weights were not different (298, 294, 282 +/- 3.8 kg HSP7ON, HSP70D, HSP70Y, respectively). Bulls with HSP7OD tended to have a larger SC than HSP7ON and HSP7OY (31.09, 29.75, 29.79 +/- 0.44 cm respectively). Finally, the bulls were given an injection of Salmonella typhimiriu . Blood was drawn from the caudal vein, in EDTA tube and serum separator tube (SST), at 0, 3, 6, 9, and 24 hours. Bulls were identified by two genotypes: (1) a single nucleotide polymorphism (SNP) in the HSP70 promoter region (HSP7OSNP), (2) no SNP and the HSP coding matched the standard genome geneotype from reported nationally at NCBI (HSP70 NCBI). Heat shock protein 70 (HSP70) had an effect on monocytes, mean corpuscular volume (MCV), and mean corpuscular hemoglobin (MCH)(p0.05). Time had an effect on insulin-like growth factor (IGF), prolactin, testosterone, cortisol, haptaglobin (p0.03)