A targeting vector was designed by Dr. Yang-Xin Fu (University of Chicago) to
replace exon 2 of the Cd160 gene on chromosome 3 with a PGK-neo cassette. Exon 2 contains the initiation codon and is required for all splice variants.
The construct was electroporated into C57BL/6N-derived PRXN embryonic stem (ES) cells. Correctly targeted ES cells were injected into recipient blastocysts, and the donating investigator reported that the chimeric males were bred with C57BL/6J females to establish the colony (see SNP note below). Upon arrival, sperm was cryopreserved. To establish our live colony, an aliquot of frozen sperm was used to fertilize C57BL/6J oocytes (Stock No. 000664).
A 48 SNP (single nucleotide polymorphism) panel analysis, with 43 markers covering all 19 chromosomes and the X chromosome, as well as 5 markers that distinguish between the C57BL/6J and C57BL/6N substrains, was performed on the rederived living colony at The Jackson Laboratory Repository. Three of the 27 markers throughout the genome were segregating, suggesting an incomplete backcross. Three of 5 markers that determine C57BL/6J from C57BL/6N were found to be segregating. These data suggest the mice sent to The Jackson Laboratory Repository were on a mixed C57BL/6J ; C57BL/6N genetic background.
