Skip to main content
Figure 3 | BMC Developmental Biology

Figure 3

From: Ultrastructural analysis of development of myocardium in calreticulin-deficient mice

Figure 3

Myofibrillar ultrastructure in the developing ventricular myocardium of WT (A, C, E) and calreticulin KO hearts (B, D, F). Magnification 10,000×. At 12.5 dpc, the ventricular myofibrils of both phenotypes are only a few sarcomeres in length (A and B). These early myofibrils exhibit disarray, which is considerably more pronounced in the calreticulin KO (B) than in the WT (A) ventricular myocardium. At 14.5 dpc, ventricular myofibrils of WT (C) and to a much lesser extent the calreticulin KO (D) become less disarrayed, and start to align with the long axis of the cardiomyocyte. At 18.5 dpc, most of the ventricular myofibrils of WT phenotype (E) run in straight courses aligned parallel to each other with their Z-lines in register, thus showing little if any myofibrillar disarray. Even thought calreticulin KO myofibrils become less disarrayed with embryonic development (F), their Z-lines are frequently not aligned (F). Calreticulin KO ventricular myofibrils, already wavier in their appearance than the corresponding WT ventricular myofibrils by 13.5 dpc, do not straighten with further embryonic development as their counterparts but become visibly wavier (C vs D). This difference in the degree of waviness is most noticeable at the latest stage of embryonic development investigated, 18.5 dpc (E vs F).

Back to article page