Characterization of Small HSPs from Anemonia viridis Reveals Insights into Molecular Evolution of Alpha Crystallin Genes among Cnidarians

Abstract

Gene family encoding small Heat-Shock Proteins (sHSPs containing α-crystallin domain) are found both in prokaryotic and eukaryotic organisms; however, there is limited knowledge of their evolution. In this study, two small HSP genes termed AvHSP28.6 and AvHSP27, both organized in one intron and two exons, were characterised in the Mediterranean snakelocks anemone Anemonia viridis. The release of the genome sequence of Hydra magnipapillata and Nematostella vectensis enabled a comprehensive study of the molecular evolution of α-crystallin gene family among cnidarians. Most of the H. magnipapillata sHSP genes share the same gene organization described for AvHSP28.6 and AvHSP27, differing from the sHSP genes of N. vectensis which mainly show an intronless architecture. The different genomic organization of sHSPs, the phylogenetic analyses based on protein sequences, and the relationships among Cnidarians, suggest that the A.viridis sHSPs represent the common ancestor from which H. magnipapillata genes directly evolved through segmental genome duplication. Additionally retroposition events may be considered responsible for the divergence of sHSP genes of N. vectensis from A. viridis. Analyses of transcriptional expression profile showed that AvHSP28.6 was constitutively expressed among different tissues from both ectodermal and endodermal layers of the adult sea anemones, under normal physiological conditions and also under different stress condition. Specifically, we profiled the transcriptional activation of AvHSP28.6 after challenges with different abiotic/biotic stresses showing induction by extreme temperatures, heavy metals exposure and immune stimulation. Conversely, no AvHSP27 transcript was detected in such dissected tissues, in adult whole body cDNA library or under stress conditions. Hence, the involvement of AvHSP28.6 gene in the sea anemone defensome is strongly suggested.

Maintenance of a Protein Structure in the Dynamic Evolution of TIMPs over 600 Million Years

“…The topology of the tree and the phylogenetic relationships, as herein described, provides additional data on cnidarians evolutionary status confirming their ancestral molecular complexity as previously demonstrated (Technau et al 2005; Nicosia et al 2014 ). This is consistent with the presence of genes responsible for the development of bilaterian traits, such as mesoderm and bilaterality, in their genomes ( Finnerty et al 2004 ; Fritzenwanker et al 2004 ; Martindale et al 2004 ).…”

Small heat shock proteins, phylogeny in filamentous fungi and expression analyses in Aspergillus nidulans

“…According to the phylogenetic analysis, gene duplication probably occurred before divergence of P. rubens and P.roqueforti, and more recently, during the evolution of A. nidulans. Notably, expansion of sHSP family by gene duplication has been found in plant and animal as well, i.e., the duplication of hsp17a/hsp17b in barley and AvHSP28.6/AvHSP27 in Anemonia viridis Nicosia et al, 2014). Interestingly, in A. viridis, the two sHSP duplicates are highly diverged in expression, e.g., AvHSP28.6 is constitutively expressed in different tissues and under varied stress condition, whereas the transcript of AvHSP27 cannot be detected (Nicosia et al, 2014).…”

“…Notably, expansion of sHSP family by gene duplication has been found in plant and animal as well, i.e., the duplication of hsp17a/hsp17b in barley and AvHSP28.6/AvHSP27 in Anemonia viridis Nicosia et al, 2014). Interestingly, in A. viridis, the two sHSP duplicates are highly diverged in expression, e.g., AvHSP28.6 is constitutively expressed in different tissues and under varied stress condition, whereas the transcript of AvHSP27 cannot be detected (Nicosia et al, 2014). These facts revealed that gene duplication is a general strategy for sHSP family expansion in different domains of eukaryotic life, however, the duplicates are sometimes functional diverged for better fitness.…”

Partially Purified Extracts of Sea AnemoneAnemonia viridisAffect the Growth and Viability of Selected Tumour Cell Lines

“…Specimens of A. viridis were collected from the Capo Granitola Coast (Torretta Granitola, Trapani, Italy) in the south of Sicily and maintained in Millipore Filtered Sea Water (MFSW) at 18 ± 1°C with a 12 h : 12 h light : dark photoperiod as reported in [ 30 ]. Water quality parameters (pH, salinity, nitrate, and ammonium levels) were monitored with kits to measure the water quality of the aquarium.…”