Karyotype analysis was performed on the scleractinian coral Coelastrea aspera Verrill, 1866, commonly found along temperate coasts in Japan (30–35°N) and in coastal waters in the Indian and Pacific oceans. G-banding of Coelastrea aspera was successfully performed, although the banding pattern was not as clear as that in mammals. The karyogram clearly revealed that this coral had a (hsr)homogeneously staining region in chromosome 11. This hsr consisted of (rRNA)ribosomal RNA related genes, which was demonstrated by (FISH)fluorescence in situ hybridization with probes generated using 28S (rDNA)ribosomal DNA primers and those generated through chromosome microdissection. In addition, we conducted (Ag-NOR)silver-stained nucleolus organizer region analysis and found Ag depositions in the interphase nuclei but not on rRNA gene loci and hsr(s) in the mitotic stage. The hsr of this coral was observed in approximately 50% of the metaphase spreads analyzed. This may explain the diversity of coral rDNA based on the molecular study of sequence analysis. Furthermore, it was discovered that human telomere and Alu repeated sequences were present in this Coelastrea aspera. Probes derived from human Alu sequences are expected to play an important role in the classification of corals. Overall, our data can be of great value in discriminating among scleractinian coral species and understanding their genetics, including chromosomal evolution.

We describe the establishment and characterization of a cell line, AM-HLH, obtained from a patient with Epstein-Barr virus-positive (EBV ) nodular sclerosis-type Hodgkin lymphoma (HL). The cells were positive for CD2 and CD30 and negative for CD15. The immunoglobulin heavy- and κ light-chain genes were rearranged. The karyotype was of the triploid range. Southern blotting using the EBV terminal repeat probe detected 3 hybridizing bands that were identical to those of the parental HL material. The cells expressed EBV-encoded RNAs as well as latent genes (EBNA1, EBNA2, LMP1, and LMP2A) and lytic genes (BZLF1 and BALF2). Fluorescence in situ hybridization (FISH) with the cosmid pJB8 clone containing a fragment of EBV DNA as a probe revealed multiple hybridization signals at a marker chromosome. Additional FISH using whole chromosome painting and centromere probes in combination with multicolor FISH determined that multiple EBV copies were clustered within the chromosome 20 materials of the marker chromosome. Culture supernatants of AM-HLH contained IL-10 as measured by the bead-based immunoassay. It is possible that an integrated EBV genome and cellular genes on chromosome 20 were coamplified, leading to the enhanced expression of genes involved in cell growth control. The AM-HLH cell line will be useful to clarify the role of cytokines in the development of EBV HL.

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A molecular cytogenetic analysis was conducted on the scleractinian coral Platygyra contorta, which is commonly found along temperate coasts in Japan. P. contorta was karyotyped (2n=28) by conventional G-and C-bandings, and the karyogram revealed that about 50% of the metaphase spreads had a homogenously staining region (hsr) in the terminal portion of the long arm of chromosome 12. Fluorescence in situ hybridization (FISH) showed that this hsr consisted of rRNA genes (rDNA) stained by C-banding. The presence of an hsr, which is a highly amplified rDNA, may explain the molecular diversity of coral rDNA. FISH visualized and demonstrated the presence of a telomere motif (TTA GGG) n in this coral using a human telomere probe. Furthermore, we isolated a specific FISH marker (312 bp) designated PC-T1, which was located near the centromere of chromosome 11. A sequence analysis revealed that the terminal part of PC-T1 (51 bp from the 3′ end) was 90% homologous with a Montipora capitate microsatellite and the Actinia equine 5S rRNA gene. Isolating FISH markers will assist the classification of scleractinian corals with the progression on describing their genome. The data obtained in this study will be valuable for discriminating species among scleractinian corals and understanding their genetics, including chromosomal evolution.