Bovine spongiform encephalopathy: the effect of oral exposure dose on attack rate and incubation period in cattle – an update

BMC Research Notes

Table 3 Bovine PrP genotypes in 86 cattle with numbers of dosed cattle separated by BSE status

Genotypes	Number (Frequency)	Number BSE-positive dosed	Number BSE-negative dosed	Total dosed
ORF
6:6 silent Q78 HET	28 (33%)	9	18	27
6:6 WT	25 (29%)	10	12	22
6:6 silent Q78 HOM	10 (12%)	4	3	7
6:5 silent Q78 HET	7 (8%)	3	4	7
6:6 silent N192 HET	5 (6%)	4	1	5
6:5 WT	4 (5%)	3	0	3
6:6 silent Q78 HET & silent N192 HET	3 (3%)	0	1	1
6:5 silent N192 HET	2 (2%)	0	2	2
5:5* WT	1 (1%)	1	0	1
6:6 silent P113 HET	1 (1%)	1	0	1
Promoter
23 bp +/− 12 bp +/−	31 (38%)	12	17	29
23 bp −/− 12 bp −/−	27 (33%)	10	12	22
23 bp +/+ 12 bp +/+	10 (12%)	5	3	8
23 bp +/− 12 bp +/+	8 (10%)	3	4	7
23 bp −/− 12 bp +/−	5 (6%)	3	2	5
23 bp −/− 12 bp +/+	1 (1%)	1	0	1

Genotypes 5:5, 6:6 and 6:5 refer to the copies of octapeptide repeats, 23 bp and 12 bp are the indels (− = deletion allele, + = insertion allele), Q78, P113 and N192 are silent polymorphisms, either homozygous (HOM) or heterozygous (HET) at position 78, 113 and 192 of the ORF respectively compared to the wild type (WT).
Four of the 86 cattle were excluded from the comparison of the promoter region because of an inconclusive assay result for the 23-bp indel.
* Exposed to 1 g in the first phase of the study and erroneously reported as having a 6:6 genotype previously [1].