Dynamics of pigment pattern formation in the zebrafish,Brachydanio rerio. II. Lability of lateral line stripe formation and regulation of pattern defects

✍ Scribed by Milos, Nadine ;Dingle, Allan D.

• Publisher: John Wiley and Sons
• Year: 1978
• Tongue: English
• Weight: 598 KB
• Volume: 205
• Category: Article
• ISSN: 0022-104X
• DOI: 10.1002/jez.1402050206

✦ Synopsis

Abstract

The operation of a pigment cell “exclusion principle” during establishment of the lateral line melanophore band was investigated in the zebrafish, Brachydanio rerio. Counts were made of second round melanophores appearing in the horizontal skeletegenous septum in the area bounded by somite No. 11. An average of 1.6 second round melanophores developed in that somite by day 8 when it was initially unoccupied, but when a first wave melanophore was already established in somite No. 11, the value dropped to only 0.2 second round cells per fish. Analysis of the entire lateral line stripe of many fish revealed that second round melanophore exclusion increases with increasing density of 3‐day (first wave) melanophores.

Lability of second round melanophore appearance was tested by creating both small and large defects in the 3‐day stripe. Following extirpation of first wave melanophores from somite No. 11, the appearance of 1.6 (average) second round melanophores per fish re‐established total counts equivalent to controls (1.7). This capacity for numerical regulation was further tested by destroying all first wave melanophores in the stripe. Second round melanophore development restored the stripe to approximately 90% of control values.

Second wave melanophore appearance in this stripe is therefore labile; the process is subject to “exclusion” by first wave cells and is capable of repairing perceived defects such that numerical pattern regulation occurs.