Inability to fix the Lewis haplotype on the ACI background in a congenic breeding program.
D000818:Animals; D003433:Crosses, Genetic; D005260:Female; D006238:Haploidy; D006579:Heterozygote; D008297:Male; D051381:Rats; D011912:Rats, Inbred ACI / Q000235:genetics*; D011917:Rats, Inbred Lew / Q000235:genetics*; D011919:Rats, Inbred Strains / Q000235:genetics*