Neurotrophin-3 and TrkC are expressed in the outflow tract of the developing chicken heart.

Transcripts encoding trkC and full-length (catalytic) TrkC receptors were detected in the outflow tract of the chicken heart during early development (stage 17; embryonic day [E] 2.5) before the start of septation. Expression of trkC mRNA persisted through early septation (stage 25, E4.5–E5) but was no longer evident by the end of septation (stage 34, E8). Neurotrophin-3 (NT-3) mRNA was also shown to be present in the outflow tract throughout cardiac development. Quail–chick chimeras were used to confirm that cardiac neural crest cells were not present in the outflow tract at stage 17 (E2.5). Our results show that NT-3 interacts with cells in the outflow tract that are not of neural crest origin. This finding indicates that, in addition to effects on neural crest cells, NT-3 may be important for cardiac development due to its interaction with cells in the outflow tract such as those arising from the secondary heart field. Developmental Dynamics 230:767–772, 2004. © 2004 Wiley-Liss, Inc.