Journal article

Publication year: 1987

Pages: 51-58

Journal: Roux's archives of developmental biology

Volume number: 196

Issue number: 1

ISSN: 0930-035X

DOI Link: https://doi.org/10.1007/BF00376021

Publisher: Springer

Abstract: 
Among zygotes of Platynereis dumerilii
treated with cytochalasin B (CCB) prior to first cleavage, a wide
variety of developmental effects were observed. One effect is a delay in
the first cleavage. Treated embryos may skip the first or even more
than one cleavage cycle and become multinucleated. Once these eggs start
cleaving their cleavage plane takes the same position as in
synchronously fertilized controls. Accordingly, the first cleavage in
embryos having skipped the first normal cleavage cycle is meridional and
equal, but their second cleavage is equatorial as in the third cleavage
in controls. None of the embryos that were observed to skip early
cleavages showed normal organogenesis, but developed into vesicle-shaped
embryos with little cytological differentiation. Another effect of CCB
treatment is altered blastomere size in those embryos which begin
cleaving in synchrony with controls. While the majority of treated
embryos followed a normal cleavage pattern, i.e. they cleaved at the
right time and inequally, some of them cleaved equally or almost equally
(adequally). Most of these embryos showed cleavage defects in
subsequent cleavage cycles and became abnormal vesicle-shaped embryos.
However, some of these embryos cleaving on schedule and equally or
adequally developed into juvenile worms showing complete duplication of
urites and parapodial rows (0.3% of all treated eggs) and are described
as Janus duplicitates. This means that the occurrence of duplicitates
and geometrically altered first cleavage patterns are correlated
phenomena. The character and origin of the duplications and the
consequences for dorsoventral polarity are discussed.

Harvard Citation style: Dorresteijn, A., Bornewasser, H. and Fischer, A. (1987) A correlative study of experimentally changed first cleavage and Janus development in the trunk of Platynereis dumerilii (Annelida, Polychaeta), Roux's archives of developmental biology, 196(1), pp. 51-58. https://doi.org/10.1007/BF00376021

APA Citation style: Dorresteijn, A., Bornewasser, H., & Fischer, A. (1987). A correlative study of experimentally changed first cleavage and Janus development in the trunk of Platynereis dumerilii (Annelida, Polychaeta). Roux's archives of developmental biology. 196(1), 51-58. https://doi.org/10.1007/BF00376021