Further evidence for a developmental change in morphogenetic properties of embryonic chick heart cells

✍ Scribed by Lesseps, Roland J. ;Brown, Shelia A.

• Publisher: John Wiley and Sons
• Year: 1974
• Tongue: English
• Weight: 446 KB
• Volume: 187
• Category: Article
• ISSN: 0022-104X
• DOI: 10.1002/jez.1401870209

✦ Synopsis

Abstract

Recent experiments involving the reaggregation of dissociated cells and fusion of intact tissue fragments have indicated that whereas heart cells and tissue fragments from young chick embryos (1.5–2 days) displayed a tendency to assume external positions in combination with neural tube, those from older embryos (4–5 days) tended to segregate to the inside of neural tube. In the present experiments, we have used the same techniques in conjunction with autoradiography to determine the relative positions of two‐day and five‐day heart ventricle cells in fusion masses and in reaggregates. Sections of 30 fusion masses revealed that the two‐day heart fragment enveloped the five‐day heart fragment in every case. Sections of 29 reaggregates showed that the two‐day and five‐day heart cells were still randomly mixed at the end of the two and one‐half day culture period. The consistent spreading of intact two‐day heart ventricle fragments over five‐day heart ventricle fragments confirms the indication of the previous experiments that heart cells change their morphogenetic properties between two days and five days of incubation. The failure of five‐day and two‐day heart cells to sort out from one another could be due to a decreased cohesiveness of five‐day heart cells caused by the trypsin dissociation procedure.