Genomic organization and expression demonstrate spatial and temporal Hox gene colinearity in the lophotrochozoan Capitella sp. I.
Genomic organization and expression demonstrate spatial and temporal Hox gene colinearity in the lophotrochozoan Capitella sp. I.
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DOI：
10.1371/journal.pone.0004004
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发表时间：
2008
期刊：
影响因子：
3.7
通讯作者：
Seaver, Elaine C.
中科院分区：
文献类型：
--
作者：
Frobius, Andreas C.;Matus, David Q.;Seaver, Elaine C.
Hox基因在许多动物中沿前后轴确定区域特征。在许多物种中，Hox基因聚集在基因组中，基因的相对顺序与体内的表达位置相对应。先前的Hox基因研究在光线虫中只报道了Hox基因的一个子集的表达和/或缺乏详细的基因组组织信息，限制了对这一多样化动物进化枝的时空共线性的解释。我们研究了分节多毛类环节动物小头藻（Capitella sp.）中单个Hox基因补体的表达和基因组组织。在小头藻中，总基因组搜索鉴定出11个Hox基因，代表了11个不同的平行类群，这些类群被认为代表了祖先磷藻补体。11个小白菜Hox基因中至少有8个基因组连接在一个簇中，具有相同的转录取向，并且缺乏分散的非Hox基因。通过原位杂交研究，我们发现11个小蠊Hox基因在空间和时间上普遍表现出共线性。除CapI-Post1外，Hox小头虫基因在幼虫发育过程中均在广泛的外胚层结构域表达，这与提供沿前后轴的位置信息一致。前基因CapI-lab、CapI-pb和CapI-Hox3在节段出现之前启动表达，而更多后基因在节段出现时或出现后不久启动表达。许多Hox小头虫基因有一个前后表达边界，与胸腹过渡相吻合，这是一个主要的身体tagma边界。变态发生后，几种表达模式发生改变，包括出现明显的后界和中枢神经系统受限。小头动物Hox基因保持了集群组织，在其他后生动物中以典型的前后顺序表达，并表现出时空共线性，反映了Hox基因特征可能存在于原口-后口动物祖先中。
Hox genes define regional identities along the anterior–posterior axis in many animals. In a number of species, Hox genes are clustered in the genome, and the relative order of genes corresponds with position of expression in the body. Previous Hox gene studies in lophotrochozoans have reported expression for only a subset of the Hox gene complement and/or lack detailed genomic organization information, limiting interpretations of spatial and temporal colinearity in this diverse animal clade. We studied expression and genomic organization of the single Hox gene complement in the segmented polychaete annelid Capitella sp. I. Total genome searches identified 11 Hox genes in Capitella, representing 11 distinct paralog groups thought to represent the ancestral lophotrochozoan complement. At least 8 of the 11 Capitella Hox genes are genomically linked in a single cluster, have the same transcriptional orientation, and lack interspersed non-Hox genes. Studying their expression by situ hybridization, we find that the 11 Capitella Hox genes generally exhibit spatial and temporal colinearity. With the exception of CapI-Post1, Capitella Hox genes are all expressed in broad ectodermal domains during larval development, consistent with providing positional information along the anterior–posterior axis. The anterior genes CapI-lab, CapI-pb, and CapI-Hox3 initiate expression prior to the appearance of segments, while more posterior genes appear at or soon after segments appear. Many of the Capitella Hox genes have either an anterior or posterior expression boundary coinciding with the thoracic–abdomen transition, a major body tagma boundary. Following metamorphosis, several expression patterns change, including appearance of distinct posterior boundaries and restriction to the central nervous system. Capitella Hox genes have maintained a clustered organization, are expressed in the canonical anterior–posterior order found in other metazoans, and exhibit spatial and temporal colinearity, reflecting Hox gene characteristics that likely existed in the protostome–deuterostome ancestor.
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影响因子：
2.4
作者：
Damen, WGM;Tautz, D
通讯作者：
Tautz, D
DOI：
10.1002/neu.480241012
发表时间：
1993-10-01
期刊：
JOURNAL OF NEUROBIOLOGY
影响因子：
--
作者：
AISEMBERG, GO;WYSOCKADILLER, J;MACAGNO, ER
通讯作者：
MACAGNO, ER
影响因子：
11.4
作者：
DUBOULE, D;DOLLE, P
通讯作者：
DOLLE, P
影响因子：
11.4
作者：
DUBOULE, D;BARON, A;GALLIOT, B
通讯作者：
GALLIOT, B
影响因子：
64.8
作者：
de Rosa, R;Grenier, JK;Balavoine, G
通讯作者：
Balavoine, G