Plastid-derived single gene minicircles of the dinoflagellate ceratium horridum are localized in the nucleus
Plastid-derived single gene minicircles of the dinoflagellate ceratium horridum are localized in the nucleus
复制标题
DOI：
10.1093/molbev/msh127
复制
发表时间：
2004-07-01
影响因子：
10.7
通讯作者：
Maier, UG
中科院分区：
文献类型：
--
作者：
Laatsch, T;Zauner, S;Maier, UG
最近的报道表明，许多含多甲藻素的甲藻的叶绿体特异性蛋白质编码的小环，小质粒样分子，每个含有一个或两个多肽基因。这些多肽的基因是叶绿体特异性的，因为它们来自其他光合真核生物的同源物仅在叶绿体基因组中编码。在这里，我们报告的分离，测序，和亚细胞定位小环的甲藻多刺角藻。梭horridum小环的组织方式与其他含多甲藻素的甲藻相同，并编码相同种类的质体特异性蛋白质，如先前的研究所报道的。从C. horridum不含小环，也不含与小环特异性探针杂交DNA。相反，C。如细胞分级分离、Southern杂交和用小环特异性探针进行的原位杂交所示，horridum小环位于细胞核中。在纯化的C. horridum质体，但它显然不是minicircular在组织，杂交与克隆探针从质体定位的DNA建议。C之间的区别。horridum和其他含多甲藻素的甲藻在小环定位水平上的优势被C. horridum的类囊体组织，这也不同于其他的多甲藻素含有甲藻，表明迄今低估的多样性的小环DNA定位和类囊体组织存在于不同的甲藻群体。
Recent reports show that numerous chloroplast-specific proteins of peridinin-containing dinoflagellates are encoded on minicircles-small plasmidlike molecules containing one or two polypeptide genes each. The genes for these polypeptides are chloroplast specific because their homologs from other photosynthetic eukaryotes are exclusively encoded in the chloroplast genome. Here, we report the isolation, sequencing, and subcellular localization of minicircles from the peridinin-containing dinoflagellate Ceratium horridum. The C. horridum minicircles are organized in the same manner as in other peridinin-containing dinoflagellates and encode the same kinds of plastid-specific proteins, as previous studies reported. However, intact plastids isolated from C. horridum do not contain minicircles, nor do they contain DNA that hybridizes to minicircle-specific probes. Rather, C. horridum minicircles are localized in the nucleus as shown by cell fractionation, Southern hybridization, and in situ hybridization with minicircle-specific probes. A high-molecular-weight DNA was detected in purified C. horridum plastids, but it is apparently not minicircular in organization, as hybridization with a cloned probe from the plastid-localized DNA suggests. The distinction between C. horridum and other peridinin-containing dinoflagellates at the level of their minicircle localization is paralleled by C. horridum thylakoid organization, which also differs from that of other peridinin-containing dinoflagellates, indicating that a hitherto underestimated diversity of minicircle DNA localization and thylakoid organization exists across various dinoflagellate groups.