Homozygous (Slc51a-/-) mice are viable and fertile, with no mRNA or protein expression from the targeted allele. Homozygotes exhibit a small growth deficit that is ameliorated after weaning, partial impairment of intestinal bile acid absorption (impaired basolateral transport of bile acids out of the ileal epithelial cell), altered regulation of bile acid synthesis, a significantly reduced bile acid pool, intestinal lengthening and intestinal hypertrophy. Homozygous mice also have reduced hepatic Cyp7a1 expression that is inversely correlated with ileal expression of fibroblast growth factor 15 (FGF15). These mutant mice may be useful in studying cholesterol metabolism, intestinal drug absorption, intestinal bile acid absorption, bile acid synthesis, and cholesterol and bile acid homeostasis.
In an attempt to offer alleles on well-characterized or multiple genetic backgrounds, alleles are frequently moved to a genetic background different from that on which an allele was first characterized. Although the donating investigator reports no observed phenotypic differences between Osta-mutant mice on a C57BL/6-congenic or B6;129S6 mixed genetic background, it should be noted that the phenotype could vary from that originally described. We will modify the strain description if necessary as published results become available.
