Mesoglein Expression During Aurelia aurita Life Cycle

Abstract

Cnidarian is thought to possess two tissue layers: endoderm (gastroderm) and ectoderm, which are separated by the layer of extracellular matrix (ECM) called mesoglea. Aurelia aurita complex life cycle consists of several stages including alternating generations of sexual adult stage medusa and asexual stage polyp (scyphistoma). The main difference between polyp and medusa is the degree of the ECM (mesoglea) development. The new protein “mesoglein” was determined as one of the main components of mesoglea. Mesoglein is the component of the mesoglea “elastic” fibers. Previously we found that according to reverse transcription PCR mesoglein is expressed in the mature medusa exclusively in the mesogleal cells. The aim of the current work was to find out at what stage of development the specific mesoglein expression occurs. Mesogleins’ expression have been checked by PCR with specific primers on the template of transcriptomes’ cDNA from different stages; by mesogleins’ antibody staining on SDSPAGE and on paraffin sections; by histochemistry staining. In A.aurita life cycle mesoglein synthesis begins at scyphystoma polyp stage at RNA and protein level in mesogleal cells (Mc) which separated at this stage as the cell type. Mesoglein stored in granules both in Mc of adult medusa and polyp on its’ way to ECM elastic fibers. Our data perfectly correspond to the recently reported de novo transcriptome assembled from Illumina RNA-Seq data generated from six stages throughout the Aurelia life cycle.