Formation of the initial kidney and mouth opening in larval amphioxus studied with serial blockface scanning electron microscopy (SBSEM).
Formation of the initial kidney and mouth opening in larval amphioxus studied with serial blockface scanning electron microscopy (SBSEM).
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DOI：
10.1186/s13227-018-0104-3
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发表时间：
2018
期刊：
影响因子：
4.1
通讯作者：
Holland ND
中科院分区：
文献类型：
--
作者：
Holland ND
对于文昌鱼的早期幼虫，Kaji等人（Zool Lett 2：2）提出，中胚层细胞被添加到形成的口的边缘，使其具有体腔管的质量，但与其他动物的口开口没有同源性。他们部分依赖于非连续的透射电子显微镜（TEM）切片，并且不能轻易地将精细的结构细节置于更广泛的背景下。文昌鱼幼虫目前的研究主要是基于连续块面扫描电子显微镜（SBSEM），一种技术揭示TEM级的细节内广泛的解剖体积，可以在三维重建。在文昌鱼幼虫口形成前不久，一个紧凑的中胚层细胞的人口是目前在第一个左体节的后端。随着发育的继续，这些细胞中更靠背的细胞产生最初的肾（哈氏肾管），而更靠腹的细胞则插入外胚层和内胚层之间的一个局部区域，在该区域，嘴很快就会穿透。SBSEM显示，在嘴巴张开后，仍然可以检测到大多数中胚层细胞，夹在外胚层和内胚层之间;它们可能是注定要发育成口周肌肉的成肌细胞。SBSEM提供了迄今为止文昌鱼幼体前端组织的最准确和详细的描述。本研究支持了Kaji等人的发现，即第一左侧体节后部区域的细胞更靠背侧产生最初的肾脏。相比之下，更腹侧的细胞（这里称为口腔中胚层）的命运就不那么清楚了。虽然Kaji等人暗示所有的口腔中胚层细胞都加入了正在形成的口腔的边缘，但SBSEM显示其中许多细胞在口腔穿透后仍然存在。即便如此，其中一些细胞在口腔渗透过程中丢失，它们的命运未知。不能排除它们如Kaji等人所提出的那样被纳入新生口的边缘。另一方面，它们可能是在外胚层和内胚层的形态发生相互作用过程中退化或从幼虫中脱落而形成的。目前的SBSEM研究，如Kaji等人，基于静态形态学数据，需要动态细胞示踪实验来确定这些可能性。
For early larvae of amphioxus, Kaji et al. (Zool Lett 2:2,) proposed that mesoderm cells are added to the rim of the forming mouth, giving it the quality of a coelomoduct without homology to the oral openings of other animals. They depended in part on non-serial transmission electron microscopic (TEM) sections and could not readily put fine structural details into a broader context. The present study of amphioxus larvae is based largely on serial blockface scanning electron microscopy (SBSEM), a technique revealing TEM-level details within an extensive anatomical volume that can be reconstructed in three dimensions. In amphioxus larvae shortly before mouth formation, a population of compact mesoderm cells is present at the posterior extremity of the first left somite. As development continues, the more dorsal of these cells give rise to the initial kidney (Hatschek’s nephridium), while the more ventral cells become interposed between the ectoderm and endoderm in a localized region where the mouth will soon penetrate. SBSEM reveals that, after the mouth has opened, a majority of these mesoderm cells can still be detected, sandwiched between the ectoderm and endoderm; they are probably myoblasts destined to develop into the perioral muscles. SBSEM has provided the most accurate and detailed description to date of the tissues at the anterior end of amphioxus larvae. The present study supports the finding of Kaji et al. that the more dorsal of the cells in the posterior region of the first left somite give rise to the initial kidney. In contrast, the fate of the more ventral cells (called here the oral mesoderm) is less well understood. Although Kaji et al. implied that all of the oral mesoderm cells joined the rim of the forming mouth, SBSEM reveals that many of them are still present after mouth penetration. Even so, some of those cells go missing during mouth penetration and their fate is unknown. It cannot be ruled out that they were incorporated into the rim of the nascent mouth as proposed by Kaji et al.. On the other hand, they might have degenerated or been shed from the larva during the morphogenetic interaction between the ectoderm and endoderm to form the mouth. The present SBSEM study, like Kaji et al., is based on static morphological data, and dynamic cell tracer experiments would be needed to decide among these possibilities.
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影响因子：
4.1
作者：
Mansfield JH;Haller E;Holland ND;Brent AE
通讯作者：
Brent AE
影响因子：
0.7
作者：
Lacalli, Thurston
通讯作者：
Lacalli, Thurston
DOI：
10.1046/j.1365-2818.1997.1940755.x
发表时间：
1997-04-01
期刊：
JOURNAL OF MICROSCOPY-OXFORD
影响因子：
--
作者：
Braet, F;deZanger, R;Wisse, E
通讯作者：
Wisse, E
影响因子：
2.9
作者：
Holland, ND;Holland, LZ
通讯作者：
Holland, LZ
影响因子：
1.2
作者：
Holland, Nicholas D.;Paris, Mathilde;Koop, Demian
通讯作者：
Koop, Demian