Polymorphism in the symmetries of gastric pouch arrangements in the sea anemone D. lineata

Zoological Letters

Koichi Fujimoto¹  Safiye E. Sarper²  Tamami Hirai³  Shigeru Kuratani⁴  Take Matsuyama⁵ 

[1] Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, 560-0043, Osaka, Japan;Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, 560-0043, Osaka, Japan;Laboratory for Evolutionary Morphology, RIKEN Center for Biosystems Dynamics Research (BDR), 650-0047, Kobe, Japan;Laboratory for Evolutionary Morphology, RIKEN Center for Biosystems Dynamics Research (BDR), 650-0047, Kobe, Japan;Laboratory for Evolutionary Morphology, RIKEN Center for Biosystems Dynamics Research (BDR), 650-0047, Kobe, Japan;Evolutionary Morphology Laboratory, RIKEN Cluster for Pioneering Research (CPR), 650-0047, Kobe, Japan;Laboratory for Retinal Regeneration, RIKEN Center for Biosystems Dynamics Research, 650-0047, Kobe, Japan;

关键词: Phenotypic variation;    Symmetry;    Cnidaria;    Anthozoa;    Gastric pouch;   

DOI  :  10.1186/s40851-021-00180-0

来源: Springer

【 摘 要 】

Symmetry in the arrangement of body parts is a distinctive phylogenetic feature of animals. Cnidarians show both bilateral and radial symmetries in their internal organs, such as gastric pouches and muscles. However, how different symmetries appear during the developmental process remains unknown. Here, we report intraspecific variations in the symmetric arrangement of gastric pouches, muscles, and siphonoglyphs, the Anthozoan-specific organ that drives water into the organism, in D. lineata (Diadumenidae, Actiniaria). We found that the positional arrangement of the internal organs was apparently constrained to either biradial or bilateral symmetries depending on the number of siphonoglyphs. Based on the morphological observations, a mathematical model of internal organ positioning was employed to predict the developmental backgrounds responsible for the biradial and bilateral symmetries. In the model, we assumed that the specification of gastric pouches is orchestrated by lateral inhibition and activation, which results in different symmetries depending on the number of siphonoglyphs. Thus, we propose that a common developmental program can generate either bilateral or biradial symmetries depending on the number of siphonoglyphs formed in the early developmental stages.

【 授权许可】

CC BY