Breter H J, Grebenjuk V A, Skorokhod A, Müller W E G
Institut für Physiologische Chemie, Universität, Duesbergweg 6, 55099 Mainz; Germany.
Prog Mol Subcell Biol. 2003;37:199-230. doi: 10.1007/978-3-642-55519-0_8.
In recent years, analyses of the genome organization of marine sponges have begun that have led to the elucidation of selected genes and gene arrangements that exist in gene clusters (e.g. the receptor tyrosine kinase cluster and the allograft inflammatory factor cluster). Most of these studies were performed with the demosponge Suberites domuncula; but Geodia cydonium (Demospongiae), Aphrocallistes vastus (Hexactinellida) and Sycon raphanus (Calcarea) were also investigated. Both S. domuncula and G. cydonium possess a surprisingly large genome of approximately 1.7 pg DNA per haploid set. Taking the high gene density in these sponges into account and considering that predominantly single-copy DNA exists, the gene number of S. domuncula and G. cydonium was estimated to be approximately 300,000. Presumably, the large gene number in the sponge genome is due to regional gene duplication; so far evidence for a transposition in sponges has been presented. Data indicate that only 0.25 % of the total sponge genome comprises CA/TG microsatellites, and until now also no SINEs/transposable elements have been identified. Due to the rapid progress in the field of molecular biology of sponges the application of sponge genes for expression studies by DNA-array techniques (microarray) has become possible. These achievements will be further supported by the systematic analysis of the expressed genome of sponges; the results will be (partially) released (http://spongebase.uni-mainz.de/cgi-bin/blast/blastserver.cgi). In our efforts employing the results from the analysis of the genome to molecular biotechnology, we applied the technique of differential display of mRNA. One example, the effect of silicate on gene expression in S. domuncula, is outlined here. Future results will allow the identification of the genes involved in the synthesis of bioactive compounds from sponges [Porifera]. This progress will contribute considerably to a fruitful and fast development in the field of molecular marine biotechnology.
近年来，对海洋海绵基因组组织的分析已经展开，这些分析已促使人们阐明了存在于基因簇中的特定基因和基因排列（例如受体酪氨酸激酶簇和同种异体移植炎症因子簇）。这些研究大多是在寻常海绵纲的白枝海绵上进行的；不过也对地穴海绵（寻常海绵纲）、大 Aphrocallistes vastus（六放海绵纲）和萝卜海绵（钙质海绵纲）进行了研究。白枝海绵和地穴海绵都拥有一个惊人的大基因组，每个单倍体基因组约有 1.7 皮克 DNA。考虑到这些海绵中的基因密度很高且主要存在单拷贝 DNA，估计白枝海绵和地穴海绵的基因数量约为 300,000 个。推测海绵基因组中的大量基因是由于区域基因重复；到目前为止，已经提出了海绵中存在转座的证据。数据表明，海绵基因组总数中只有 0.25% 由 CA/TG 微卫星组成，而且到目前为止也未鉴定出短散在核元件/转座元件。由于海绵分子生物学领域的快速发展，利用 DNA 阵列技术（微阵列）将海绵基因应用于表达研究已成为可能。海绵表达基因组的系统分析将进一步支持这些成果；结果将（部分）发布（http://spongebase.uni-mainz.de/cgi-bin/blast/blastserver.cgi）。在我们利用基因组分析结果开展分子生物技术的工作中，我们应用了 mRNA 差异显示技术。这里概述了一个例子，即硅酸盐对白枝海绵基因表达的影响。未来的结果将有助于鉴定参与海绵[多孔动物门]生物活性化合物合成的基因。这一进展将极大地推动分子海洋生物技术领域富有成效且快速的发展。
