Establishment of human apoB-100 transgenic (Tg.) SHR-cp/cp rats.
To generate human apoB-100 transgenic rats, we injected human genomic DNA containing the full length of the human apoB-100 gene into fertilized eggs of Wistar rats. To select a transgenic rat line showing stable hyperlipidemia, expression analyses and phenotypic analyses were carried out among the four lines obtained. Then the male rats carrying the human apoB-100 transgene were backcrossed four times with SHR-+/+ rats to replace the genome of the Wistar rat by the speed congenic method. A TaqMan Copy Number Assay (HS02237611_cn, Life Technologies, Carlsbad, CA, USA) was used to detect human apoB transgene in the genome of rats. Then male N4 rats were crossed with SHR-cp/+ rats to introduce cp mutations into the N5 rats. Finally, backcrosses to SHR rats were carried out nine times. Then human apoB Tg. SHR-cp/+ rats were crossed with non-Tg. SHR -cp/+ rats to obtain human apoB Tg. SHR-cp/cp rats and their littermates. Selection of the best human apoB Tg. male rats for subsequent backcrossing was based on genotyping by MAX-BAX service (Charles River) using 110 markers scattered throughout the whole genome. SHR-cp/cp, SHR-cp/+, and SHR-+/+ rats were provided by the Disease Model Cooperative Research Association (Kyoto, Japan). The human apoB Tg. SHR-cp/+ rats will be deposited in the National BioResource Project for the Rat in Japan and will be available from the project.