Identification and expression analysis of a heat-shock protein 70 gene in Polycelis sp.

Abstract

Heat-shock protein 70 (HSP70) is ubiquitously found in a variety of organisms and plays an important role in cytoprotection, environmental monitoring, and disease resistance. In this study, the full-length complementary DNA (cDNA) of hsp70 from planarian Polycelis sp. was first cloned using rapid amplification of cDNA ends (RACE). The expression levels of Pyhsp70 were analyzed in the presence of various stressors by real-time PCR, and its temporal-spatial expression patterns were also examined in both intact and regenerative animals by whole-mount in situ hybridization. The results show that (1) the deduced amino acid sequence of Pyhsp70 includes three typical HSP70 family signature motifs and is highly conserved during evolution; (2) Pyhsp70 expression is induced by prolonged starvation, tissue damage, and ionic liquid but inhibited by high or low temperatures; and (3) Pyhsp70 mRNA is mainly expressed in the head peripheral region and in the regenerating blastema during regeneration. These results suggest that the highly expressed Pyhsp70 gene may contribute to enhance cytoprotection and tolerance against stress-induced molecular damage, and the migration of neoblasts to the wound, which might also be involved in the proliferation and differentiation of neoblasts. Our work provides basic data for the study of stress responses and regenerative mechanism in freshwater planarians.

Identification of a HSP40 gene involved in planarian regeneration

“…In intact animals, the transcripts of Djhsp60and Djhsp70-related gene (Djmot) have been detected in parenchymal tissue, where the neoblasts are distributed, and these transcripts have been upregulated in the regenerative blastema (Conte et al 2009(Conte et al , 2010Fernandez-Taboada et al 2011;Isolani et al 2012;Cheng et al 2015). In our work, the expression level of Djhsp40 gradually increased during regeneration, and the transcripts were distributed specifically in the blastema, where neoblasts and their descendants migrated to regenerate the lost body parts.…”

“…Previous studies revealed that hsp70 and hsp60 genes are involved in planarian regeneration (Conte et al 2009(Conte et al , 2010Fernandez-Taboada et al 2011;Isolani et al 2012;Cheng et al 2015); therefore, we aimed to understand whether hsp40 gene is also involved in this process. We employed qPCR to detect the dynamic changes in Djhsp40 expression at different days following amputation.…”