Expression and cellular localization of maternal factor boule in gonad of sea urchin Mesocentrotus nudus
HAN Yalun, WEI Jinliang, CUI Zhouping, ZHANG Jian, ZHANG Weijie, WEN Bin, CHANG Yaqing*, SUN Zhihui*
Key Laboratory of Mariculture & Stock Enhancement in North China’s Sea, Ministry of Agriculture and Rural Affairs, Dalian Ocean University, Dalian 116023, China
Abstract: In order to identify the germ cell marker genes of sea urchin Mesocentrotusnudus, molecular characteristics and dynamic expression patterns of boule gene were elucidated in the sea urchin (body mass of 76.8 g±10.0 g) by means of gene cloning, Real-time quantitative PCR (RT-qPCR) PCR and in situ hybridization in sections. It was found that the full length of boule cDNA sequence was 1 788 bp, with the length of 3′untranslated region of 601 bp, 5′untranslated region of 146 bp and open reading frame of 1 041 bp, encoding a total of 346 amino acids including a conservative RRM domain. Real-time quantitative PCR (RT-qPCR) analysis revealed that boule protein was a maternal factor being expressed throughout the embryonic development. In addition, boule gene was expressed in intestine, tube foot, coelomic fluid and the gonad (stage Ⅱ), with the maximum expression level in testis. In ovary with the maturation of oocytes, the expression of boule gene was increased gradually to stage IV, with the maximum level, and the expression of boule gene was higher in testis only at stage Ⅱ and stage Ⅲ. Section in situ hybridization showed that boule gene was expressed specifically in male germ cells, without detection of boule in positive cells in ovary. By combining all the analysis results, boule gene of sea urchin is a marker gene in male germ cells and the findings lay a foundation for the study of male germ cell development of sea urchin.
2021, Vol. 36 
