Desmosine and hydroxyproline contents (A–F) and elastic fiber-related gene expression (G–K) of the ascending aorta of 3 weeks, 6 and 24-month-old Fbn1+/+ and Fbn1+/mgΔ mice. D,E present the desmosine and hydroxyproline ratios relative to total protein content. The general effect of genotype (G) and age (A) was assessed by two-way ANOVA separately in each condition (A to K), and followed by Fisher’s LSD test for paired comparisons: *,#Significant difference between Fbn1+/+ and Fbn1+/mgΔ mice of the same age, and between 6- and 24-months-old mice of the same genotype, respectively. §Significant difference between young (3-week-old) on one hand and 6- and 24-month old animals of the same genotype on the other hand. +Significant difference between young (3-week-old) and 6-month old animals of the same genotype on the other hand. For desmosine and hydroxyproline dosages: n=5–7 (6-month-old mice) and n=3–5 (24-month-old mice) in each group. For mRNA expression: n=6 (3-week-old), n=8 (6-month-old) and n=5–7 (24-month-old) in each group.