FIGURE 1.

Nf1-deficient rat breast cancer lines have increased matrix before tumor formation. (A) Schematic of indels generated in one copy of the Nf1 gene in immunocompetent Sprague Dawley rats resulting in three Nf1 mutant lines: Nf1 in frame (IF/+), premature stop-20 (PS-20/+), as well as in-frame and premature stop-21 (IF; PS-21/+). (B) Tumor onset in Nf1-deficient rats. All animals in this study died of mammary tumor progression. Representative H&E images and eosin quantification of rat mammary gland at (C) 21 and (D) 33 days. (E) Representative brightfield and polarized microscopy images of picrosirius red (PSR)-stained rat mammary glands at 43 days, and quantification of polarized light signal. Each data point represents a tissue from an individual rat as a biological replicate.