The polymeric Ig Receptor (pIgR) has been reported as an important player of immune system in various teleost fish, all living in temperate marine environments, but very little is known on cold adapted species. To expand the current knowledge in the field, the present study had the purpose of identifying and characterizing the gene encoding the pIgR in the cold adapted teleost Trematomus bernacchii, a species belonging to the Perciform suborder Notothenoidei, the most abundant component of the fish fauna living in the Antarctic Ocean. The T. bernacchii pIgR gene was analyzed in comparison with the homologous gene from 11 cold adapted species (crynotothenioids) along with one species, Cottoperca gobio, which belongs to Bovichtidae, the phyletically basal notothenioid family inhab- iting the less cold sub-Antarctic region. In addition, multiple temperate species, representative of five perciform suborders, were considered for comparative analysis. Cryonototheniod pIgR genes showed several unex- pected features such as the largest size, mainly due to introns two to three times longer, the presence of conserved motifs associated with transpos- able elements, and additional regulatory signals. Comparative analysis of T. bernacchii pIgR cDNA and deduced amino acid sequences from other investigated perciform species revealed distinct features of Antarctic pIgR. Remarkably, the presence of up to four N-glycosylation sites, which is unusual in teleost pIgR, strongly suggested a putative role in the adaptive response to cold. Expression analyses of T. bernacchii pIgR were performed by q-PCR and in situ hybridization on gut, gills, liver and head kidney. pIgR transcripts were found to be predominantly expressed in the gills. Overall, these findings uncover significant modifications of the pIgR gene from Antarctic fish and suggest a fine-tuned regulation of its expression under cold conditions. To the best of our knowledge this is the first report on pIgR in cold adapted teleosts.
Structure and expression of the polymeric Ig receptor gene from Antartctic teleosts
Alessia Ametrano;Umberto Oreste;Maria Rosaria Coscia
2022
Abstract
The polymeric Ig Receptor (pIgR) has been reported as an important player of immune system in various teleost fish, all living in temperate marine environments, but very little is known on cold adapted species. To expand the current knowledge in the field, the present study had the purpose of identifying and characterizing the gene encoding the pIgR in the cold adapted teleost Trematomus bernacchii, a species belonging to the Perciform suborder Notothenoidei, the most abundant component of the fish fauna living in the Antarctic Ocean. The T. bernacchii pIgR gene was analyzed in comparison with the homologous gene from 11 cold adapted species (crynotothenioids) along with one species, Cottoperca gobio, which belongs to Bovichtidae, the phyletically basal notothenioid family inhab- iting the less cold sub-Antarctic region. In addition, multiple temperate species, representative of five perciform suborders, were considered for comparative analysis. Cryonototheniod pIgR genes showed several unex- pected features such as the largest size, mainly due to introns two to three times longer, the presence of conserved motifs associated with transpos- able elements, and additional regulatory signals. Comparative analysis of T. bernacchii pIgR cDNA and deduced amino acid sequences from other investigated perciform species revealed distinct features of Antarctic pIgR. Remarkably, the presence of up to four N-glycosylation sites, which is unusual in teleost pIgR, strongly suggested a putative role in the adaptive response to cold. Expression analyses of T. bernacchii pIgR were performed by q-PCR and in situ hybridization on gut, gills, liver and head kidney. pIgR transcripts were found to be predominantly expressed in the gills. Overall, these findings uncover significant modifications of the pIgR gene from Antarctic fish and suggest a fine-tuned regulation of its expression under cold conditions. To the best of our knowledge this is the first report on pIgR in cold adapted teleosts.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
