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.
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.
The medusa, Aurelia aurita (Scyphozoa, Cnidaria), is considered to be 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 basic morphology of medusa is similar in different populations. Previously we have determined a new protein "mesoglein" as one of the main components of mesoglea. Deduced amino acid sequence of mesoglein contains Zona Pellucida (ZP) domain. In this paper, we have comparied of mesoglein and its gene in medusa from three habitats (White Sea (WsA), Black Sea (BsA), Japonic Sea (JsA)). 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 mesogleins 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 divergency was checked by PCR with primers specific for WsA mesoglein gene. PCR products of expected length obtained on polyA-cDNA 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. inhabits Japonic Sea. This is consistent with findings of other recept molecular biological studies.
Abstract Most of the human genome is non-coding. However, some of the non-coding part is transcriptionally active. In humans, the tandemly repeated (TR) pericentromeric non-coding DNA—human satellites 2 and 3 (HS2, HS3)—are transcribed in somatic cells. These transcripts are also found in pre- and post-implantation embryos. The aim of this study was to analyze HS2/HS3 transcription and cellular localization of transcripts in human maturating oocytes. The maternal HS2/HS3 TR transcripts transcribed from both strands were accumulated in the ooplasm in GV-MI oocytes as shown by DNA–RNA FISH (fluorescence in-situ hybridization). The transcripts’ content was higher in GV oocytes than in somatic cumulus cells according to real-time PCR. Using bioinformatics analysis, we demonstrated the presence of polyadenylated HS2 and HS3 RNAs in datasets of GV and MII oocyte transcriptomes. The transcripts shared a high degree of homology with HS2, HS3 transcripts previously observed in cancer cells. The HS2/HS3 transcripts were revealed by a combination of FISH and immunocytochemical staining within membraneless RNP structures that contained DEAD-box helicases DDX5 and DDX4. The RNP structures were closely associated with mitochondria, and are therefore similar to membraneless bodies described previously only in oogonia. These membraneless structures may be a site for spatial sequestration of RNAs and proteins in both maturating oocytes and cancer cells.
