Fig. 2.

Perinatal titin isoform switching in rat heart. 1 Adult rat heart expresses N2B, N2BA and NT-titins. 2 Fetal hearts 3 day before birth (e19) expresses more long (embryonic) N2BA-isoform of titin and N2B-titin. 3, 4 Two days after birth (3) and 14 days after birth (4), N2B and N2BA-titins are expressed in rat heart. MHC Heavy chains of myosin; T1 intact titin; T2 proteolytic fragments of titin. Vertical agarose-strengthened 2.1% polyacrylamide gel (8 × 10 × 0.1 cm) was used to separate the titin isoforms