Cloning And Expression Pattern Of SUMOylation Genes In Chinese Mitten Crab, Eriocheir Sinensis

SUMO is a member of the family of ubiquitin-related proteins which widely found in eukaryotes. SUMOs have been extensively studied in higher vertebrates while invertebrates have received little attention. SUMO modification plays important roles in regulation of transcription, and protein localisation and cellular processes.In this study, four SUMOylation genes EsSUMO, EsAosl/EsUba2and EsUbc9were identified in E. sinensis. Bioinformatics analyses showed that EsSUMO encodes a protein of93amino acids; EsAosl encodes a protein of345amino acids; EsUba2encodes a protein of649amino acids; EsUbc9encodes a protein of160amino acids. EsSUMO contains the conserved ΨKXE/D motif and GG repeats; EsAosl contains Aosl-Uba2interaction residues region; EsUba2contains putative ATP binding site and cysteine residue; EsUbc9contains the UBC domain and cysteine residue.The four SUMOylation genes EsSUMO, EsAosl/EsUba2and EsUbc9expressions were widely observed in all organs tested using qRT-PCR. Expressions of EsSUMO and EsUbc9were highest in testis, ovary and muscle, and comparable in other organs. Both EsSUMO and EsUbc9expressions were lowest in intestine, haemocytes, and stomach. Expressions of EsAosl/EsUba2were comparable in EsSUMO and EsUbc9. In addition, in the testis, SUMOylation genes were expressed at moderate levels in stage Ⅱ-1, increased at stage Ⅱ-2, and then gradually declined in stage IV. In the ovary, SUMOylation genes expressions were low in the early stage, reached the highest level at stage Ⅲ-2, and then decreased in stage Ⅳ. SUMOylation genes were expressed at high levels in the gonads, implying that SUMOylation may play important roles in gonad development and gametogenesis.Transcripts from two SUMOylation genes were detected in the testis and ovary using in situ hybridization. In the testes, EsSUMO and EsUbc9transcripts mainly localized to spermatocyte and spermatid. In the ovaries, EsSUMO and EsUbc9transcripts were also detected in mature ovaries. The pattern of EsSUMO and EsUbc9expression in the testis and ovary suggests SUMOylation may play an important role in spermatogenesis and oogenesis in Eriocheir sinensis.