FIG 1.

Ext1^HEP mutant mice lack hepatic heparan sulfate. (a) Schematic representation indicating conditional excision of exon 1 of the Ext1 gene via Cre recombinase cleavage at loxP sites (white triangles). Upon Cre recombination, the Ext1 gene is inactivated in hepatocytes (Ext1^f/f;AlbCre⁺ [Ext1^HEP]). (b) PCR analysis of Ext1 deletion in primary hepatocytes from Ext1^f/f control and Ext1^HEP mutant mice, using the primer pairs indicated in panel a. (c) Quantitative glycosaminoglycan analysis in liver tissue. Heparan sulfate (HS) content was analyzed by glycan reductive isotope labeling-LC/MS. The graph illustrates data from 3 control and 3 mutant mice. Values are means ± SD. **, P < 0.01. Comparable results were obtained with two independent preparations of liver tissue.