Appendage regeneration after autotomy is mediated by Baboon in the crayfish Procambarus fallax f. virginalis Martin, Dorn, Kawai, Heiden and Scholtz, 2010 (Decapoda: Astacoidea: Cambaridae)

Abstract

A B S T R A C TAutotomy is an adaptive response in which animals escape from predators by shedding their own appendages. It is made possible by the presence of an efficient mechanism for regeneration. Decapod crustaceans frequently exhibit excellent abilities to regenerate complete pereopods in just a few molts following autotomy. The molecular basis of regeneration pereopods in decapods remains unclear. We identified the primary structure of Baboon (Babo), a type I TGF-β superfamily receptor involved in the activin pathway, in the crayfish, Procambarus fallax f. virginalis Martin, Dorn, Kawai, Heiden and Scholtz, 2010. Molecular cloning revealed that babo possesses three splice variants. The expression levels of the functional babo transcript did not show increases during regeneration. RNA interference (RNAi) targeting a common region of the babo sequence, however, caused a reduction in regenerated pereopod lengths. No loss or reduction in a specific article was observed. Instead, the regenerated legs were smaller but retained the morphology and proportions of regenerated legs from control animals. Babo thus appears to control the growth, but not the pattern, of legs during the regeneration process in decapod crustaceans.

The activin signaling transcription factor Smox is an essential regulator of appendage size during regeneration after autotomy in the crayfish

“…In cricket leg regeneration, the TGF‐β superfamily BMP pathway has been shown to regulate proximal/distal axis formation (Mito et al, ; Nakamura et al, ). However, the activin pathway has not been investigated in regeneration in crickets or other arthropods until our investigations in P. fallax (Shinji et al, ), although it is well known to mediate regeneration in vertebrates (Gilbert et al, ; Ho & Whitman, ; Jaźwińska et al, ; Lévesque et al, ). Our results support the hypothesis that activin signaling is a conserved molecular pathway underlying regeneration in animals.…”

“…The expressions of babo A and babo B , which encode complete Babo structures, and two components shared among TGF‐β signaling, Med and put , were also analyzed in order to examine the relationship between the receptor and downstream transcription factor. cDNA synthesized in our previous study was used for the analysis (Shinji et al, ). cDNA samples were prepared as described above.…”

“…cDNA from embryos was used as a template for cDNA cloning (Shinji et al, 2016). cDNA was made according to Shinji et al (2016).…”

“…cDNA from embryos was used as a template for cDNA cloning (Shinji et al, 2016). cDNA was made according to Shinji et al (2016). Briefly, embryos at 6, 9 and 11 days after spawning were collected from a brooding female into ISOGEN reagent (Nippon Gene, Tokyo, Japan).…”

“…But, whether BMP signaling functions instead of, or together with, activin signaling during regeneration in this organism is not known. We recently reported that activin signaling appears to function in pereopod regeneration in a decapod crustacean, Procambarus fallax, through a type-I TGF-β receptor, Baboon (Babo) (Shinji, Gotoh, Miyanishi, & Kaneko, 2016). Thus, the level of conservation in the role of activin signaling on regeneration is still not clear, despite many animals possessing both activin signaling and regenerative capacity.…”