Mesoglein differences between two jellyfish populations of the genus Aurelia

Anastasiya V Kotova,Olga I Podgornaya,Oleg A Kovtun,Leonid S Adonin

doi:10.1007/s40071-015-0096-8

Anastasiya V Kotova, Olga I Podgornaya + Show 2 more

Open Access

https://doi.org/10.1007/s40071-015-0096-8

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Abstract

The medusa, Aurelia aurita (Scyphozoa, Cnidaria), is counted as a cosmopolitan species with a worldwide distribution in most seas, from the poles to the tropics. Cnidarian is thought to possess two tissue layers: endoderm (gastroderm) and ectoderm, which are separated by huge mesoglea in medusa. The main medusas’ morphology is similar in different populations. Previously the new protein “mesoglein” was determined as one of the main components of mesoglea. Deduced amino acid sequence of mesoglein contains Zona Pellucida (ZP) domain. The comparison of mesoglein and its gene from three habitats White Sea (WsA), Black Sea (BsA), Japonic Sea (JsA) has been done in the current work. The set of the mesoglea protein bands after SDS-PAGE is similar in all samples. Nevertheless, JsA mesogleins’ M r is 53\55 kDa, while WsA and BsA mesogleins have M r of 47 kDa. Antibodies raised against WsA mesoglein recognize only mesoglein with M r of 47 kDa, but not 53\55 kDa, both on immunoblot and immunocytochemistry. Mesogleal cells and “elastic” fibrils are stained intensively in the mesoglea both from WsA and BsA but not from JsA. The possibility of gene diversity was checked by PCR with primers specific for WsA mesoglein gene. PCR products of expected length were obtained on cDNA from polyA-RNA template from mesogleal cells of WsA and BsA medusa but not on cDNA of JsA medusa. Our results evidence that there are two different species in genus Aurelia: Aurelia aurita inhabits White and Black Seas while Aurelia sp.1 inhabits Japonic Sea. Such a suggestion is in agreement with the one previously done on the base of comparison by other molecular biology methods.

Highlights

Cnidaria is one of the most ancient animal groups which arose *550 millions year ago during the Cambrian explosion
A. aurita medusas were collected in the vicinity of the Hydrobiological Station of Odessa I.I.Mechnikov national university, Black Sea (BsA); Marine Biologcal Station ‘‘Vostok’’ of AV Zhirmunsky Institute of Marine Biology, Japan Sea (JsA); the White Sea Biological Station of the Zoological Institute RAS ‘‘Kartesh’’ (Chupa Inlet, Kandalaksha Bay in the White Sea (WsA) during the summers of 2009–2013
Medusas from White Sea (WsA) initial mesogleins’ apparent molecular mass (Mr) is 47 kDa (Figs. 1a, 2; Matveev et al 2007); same Mr revealed for mesoglein of medusa from the Black Sea (BsA)

Summary

Introduction

Cnidaria is one of the most ancient animal groups which arose *550 millions year ago during the Cambrian explosion. Aurelia aurita mesoglea contains a number of mesogleal cells (Mc). This feature is not unique but rather rare (Chapman 1966). The cosmopolitan moon jelly Aurelia is characterized by high degrees of morphological and ecological plasticity, and subsequently by an unclear taxonomic status. The latter has been revised repeatedly over the last century, dividing the genus Aurelia into as many as 12 or as little as two species (Schroth et al 2002). The degree of Aurelia morphological plasticity never influences the main medusa feature—huge mesoglea. According to this assumption we did not expect to find dramatic differences in mesoglea composition but it happens not to be so

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