Molecular cytogenetic investigation was carried out on the scleractinian coral, Acropora pruinosa (A. pruinosa). Conventional Giemsa staining techniques for karyotyping, such as G- and C-banding, were conducted. Karyotype analysis showed mosaicism of cells with two different chromosome numbers, 28 and 29, in the same embryo. The C-band positive portions appeared on the centromeres of most chromosomes and along the entire length of the unpaired chromosome 15 in cells with 29 chromosomes. Fluorescence in situ hybridization (FISH) revealed that the loci of rRNA genes (rDNA), 5S and 18S/28S, were located on chromosomes 4 and 2, respectively. Whole genome hybridization (WGH) with sperm DNA showed distinct signals not only on all centromeric regions but also on a whole unpaired chromosome 15. Comparative genomic hybridization (CGH) using DNAs from sperm and unfertilized eggs revealed that the unpaired chromosome 15 has sperm-specific DNA sequences. We therefore hypothesized the existence of a sex-related chromosome in A. pruinosa. In this study, we have presented a tentative karyotype of this coral, based on banding results, and described FISH, WGH, and CGH results. Moreover, we successfully cloned and sequenced three clones; AP-5S for 5S rDNA, AP-18S for 18S/28S rDNA, and AP-unpaired chromosome 15q for the unpaired chromosome 15-specific DNA. These molecular cytogenetic approaches will help establish a more exact karyotype of corals and promote understanding of coral genetics, including chromosome evolution. These findings will help to verify the method of classification of complex scleractinian corals.

中文翻译：

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石珊瑚 Acropora pruinosa Brook, 1982 (Hexacorallia, Anthozoa, Cnidaria) 中的核型嵌合和分子细胞遗传标记

对 scleractinian 珊瑚 Acropora pruinosa (A. pruinosa) 进行了分子细胞遗传学研究。进行了用于核型分析的常规吉姆萨染色技术，例如 G 和 C 带。核型分析显示同一胚胎中具有两种不同染色体编号（28 和 29）的细胞存在嵌合现象。C带阳性部分出现在大多数染色体的着丝粒上，并在29条染色体的细胞中沿着未配对的15号染色体的整个长度出现。荧光原位杂交 (FISH) 显示 rRNA 基因 (rDNA) 的位点 5S 和 18S/28S 分别位于染色体 4 和 2。与精子 DNA 的全基因组杂交 (WGH) 不仅在所有着丝粒区域而且在整个未配对的 15 号染色体上都显示出不同的信号。使用来自精子和未受精卵的 DNA 的比较基因组杂交 (CGH) 显示未配对的 15 号染色体具有精子特异性 DNA 序列。因此，我们假设在 A. pruinosa 中存在性相关染色体。在这项研究中，我们根据条带结果提出了这种珊瑚的初步核型，并描述了 FISH、WGH 和 CGH 结果。此外，我们成功克隆并测序了三个克隆；AP-5S 用于 5S rDNA，AP-18S 用于 18S/28S rDNA，AP 未配对染色体 15q 用于未配对的 15 号染色体特异性 DNA。这些分子细胞遗传学方法将有助于建立更准确的珊瑚核型，并促进对珊瑚遗传学的理解，包括染色体进化。这些发现将有助于验证复杂石珊瑚的分类方法。