类核体

类核体（英语：nucleomorph）又称核形体，是在隐藻^[1] 和绿蛛网藻（英语：Chlorarachniophytes）（属有孔虫界）^[2]叶绿体内的结构，位于其内外膜结构（periplastidial compartment）之间，为次级内共生中内共生体（英语：Endosymbiont）细胞核的残迹。这两类生物的叶绿体皆有四层膜，是由一个真核生物吞噬原核生物形成叶绿体后，再被另一个真核生物吞噬而来^[3][4]。类核体中也具有DNA（类核体基因组），但均已大幅退化缩减，例如蓝隐藻（英语：Guillardia theta）的类核体基因组已在2001年被测序，长度仅有551kb，只保留了513个基因^[5]；Bigelowiella natans（英语：Bigelowiella natans）（一种绿蛛网藻）的类核体基因组则在2006年被测序，仅长373kb，包含331个基因。序列分析显示隐藻的类核体来自红藻，绿蛛网藻的类核体则来自绿藻^[2]。

提示：此条目的主题不是拟核。

由次级内共生而成、具有四层膜的叶绿体中含有类核体

5 来源

相关结构

某些双鞭毛虫（Durinskia baltica与Kryptoperidinium foliaceum，合称dinotoms）的叶绿体来自硅藻，为三级内共生的产物，且其中尚存细胞核与线粒体，因此其细胞中同时含有来源不同的两种线粒体^[6]。

1 来源

参考文献

• 分子与细胞生物学主题

1. Lane, C. E.; Van Den Heuvel, K.; Kozera, C.; Curtis, B. A.; Parsons, B. J.; Bowman, S.; Archibald, J. M. Nucleomorph genome of Hemiselmis andersenii reveals complete intron loss and compaction as a driver of protein structure and function. Proceedings of the National Academy of Sciences. 2007, 104 (50): 19908–19913. Bibcode:2007PNAS..10419908L. PMC 2148396 . PMID 18077423. doi:10.1073/pnas.0707419104.
2. Gilson, P. R.; Su, V.; Slamovits, C. H.; Reith, M. E.; Keeling, P. J.; McFadden, G. I. Complete nucleotide sequence of the chlorarachniophyte nucleomorph: Nature's smallest nucleus. Proceedings of the National Academy of Sciences. 2006, 103 (25): 9566–9571. Bibcode:2006PNAS..103.9566G. PMC 1480447 . PMID 16760254. doi:10.1073/pnas.0600707103.
3. Archibald, J.M.; Lane, C.E. Going, Going, Not Quite Gone: Nucleomorphs as a Case Study in Nuclear Genome Reduction. Journal of Heredity. 2009, 100 (5): 582–90. PMID 19617523. doi:10.1093/jhered/esp055.
4. Reyes-Prieto, Adrian; Weber, Andreas P.M.; Bhattacharya, Debashish. The Origin and Establishment of the Plastid in Algae and Plants. Annual Review of Genetics. 2007, 41 (1): 147–68 [2021-04-29]. PMID 17600460. doi:10.1146/annurev.genet.41.110306.130134. （原始内容存档于2020-07-28）.
5. Archibald, John M. Nucleomorph Genomes: Structure, Function, Origin and Evolution. BioEssays. 2007, 29 (4): 392–402. PMID 17373660. doi:10.1002/bies.20551.
6. Imanian B, Pombert JF, Dorrell RG, Burki F, Keeling PJ. Tertiary endosymbiosis in two dinotoms has generated little change in the mitochondrial genomes of their dinoflagellate hosts and diatom endosymbionts.. PLoS One. 2012, 7 (8): e43763. PMC 3423374 . PMID 22916303. doi:10.1371/journal.pone.0043763.