Molecular cloning of the BCL-6 gene, a transcriptional repressor for B-cell differentiation, in torafugu ( Takifugu rubripes)

• Published in: Molecular immunology Vol. 43; no. 7; pp. 1047 - 1053
• Main Authors: Ohtani, Maki, Miyadai, Toshiaki, Hiroishi, Shingo
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.03.2006
• Subjects: Amino Acid Motifs - genetics; Amino Acid Sequence; Animals; B-cell; B-Lymphocytes - cytology; B-Lymphocytes - physiology; Base Sequence; BCL-6; Cell Differentiation - genetics; Cloning, Molecular; Exons - genetics; Introns - genetics; Molecular Sequence Data; Proto-Oncogene Proteins c-bcl-6 - chemistry; Proto-Oncogene Proteins c-bcl-6 - genetics; Repressor Proteins - chemistry; Repressor Proteins - genetics; RNA, Messenger - analysis; Takifugu - genetics; Takifugu - metabolism; Torafugu; Transcription factor; Transcription, Genetic; Zinc Fingers - genetics; Torafugu; Transcription factor; BCL-6; B-cell
• ISSN: 0161-5890; 1872-9142
• DOI: 10.1016/j.molimm.2005.06.036

B-cell lymphoma-6 (BCL-6) is a transcriptional repressor that prevents the terminal differentiation of mature B-cells to plasma cells, and is essential for germinal center formation in the primary lymphoid organs of mammals. In this study, we identified the BCL-6 gene in torafugu ( Takifugu rubripes) using the torafugu genome database, and analyzed the expression of BCL-6 mRNA in various tissues of torafugu, using RT-PCR. The BCL-6 gene consisted of eight exons and seven introns spanning a genome of ca. 3.3 kb. BCL-6 mRNA contained a 2112 bp open reading frame encoding 703 amino acids, with a predicted protein size of 78.8 kDa. The predicted torafugu BCL-6 primary structure contains two conserved specific motifs, the BTB/POZ domain at the N-terminus and the sixC 2H 2-type zinc finger motifs at the C-terminal region. The homology of torafugu BCL-6 to those of zebrafish ( Danio rerio), Xenopus laevis, mouse ( Mus musculus) and human ( Homo sapiens) is 76, 59, 60 and 60%, respectively. RT-PCR analysis revealed that BCL-6 mRNA is highly expressed in pronephros, thymus, intestine, ovary, brain, nasal cavity and muscle. These results imply that torafugu BCL-6 is involved in regulation of B-cell differentiation in torafugu.