Comparative study of spiculogenesis in demosponge and hexactinellid larvae
Comparative study of spiculogenesis in demosponge and hexactinellid larvae
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海绵海绵动物和六线海绵动物幼虫的针发生的比较研究
DOI：
10.1002/jemt.10397
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发表时间：
2003
影响因子：
2.5
通讯作者：
S. Leys
中科院分区：
文献类型：
--
作者：
S. Leys
通过电子显微镜研究了单细胞海绵Reniera sp.和六棘海绵Oopsacas minuta的固定胚胎和幼虫的骨针沉积。针状体形成于细胞内和合胞体内的中央空泡中，如成体海绵。在Reniera中，成核细胞在原肠胚形成之前从微粒体分化。在原肠胚形成时，成核细胞迁移到胚胎的外周，并开始在六角形轴丝周围沉积骨针。在自由游动的幼虫中，硬细胞有许多伪足并迁移到后极，在那里它们沿着前后轴排列。Reniera幼虫约有40 - 50个长约70 - 75 μ m、宽约1 μ m的卵囊。成熟的Oopsacas幼虫有多达14个肌动蛋白针状体，这些针状体产生于幼虫后极光滑上皮下的组织中的矩形轴丝上。幼硬细胞有许多伪足。4射线骨针沿前后轴和中轴沿着伸长，直到纵射线锚定在幼虫前部充满脂质的细胞质中，而侧射线在中线周围相交。在自由游动的幼虫中，藻肌动蛋白的横向射线的长度为27 - 45 μ m，而两条纵向射线的长度为40 - 80 μ m。虽然骨针沉积开始于细胞和合胞海绵中具有相似形态的细胞，但骨针的精细化和组织在细胞和合胞海绵中明显不同，并且似乎是非常不同的细胞分化和幼虫形态发生的结果，这些组中的每一个都发生。Microsc. Res. Tech. 62：300 - 311，2003.© 2003 Wiley利斯公司
Spicule deposition was studied by electron microscopy in fixed embryos and larvae of the haplosclerid sponge Reniera sp. and the hexactinellid Oopsacas minuta. Spicules form in centrally located vacuoles within cells and within syncytia, as in the adult sponges. In Reniera, scleroblasts differentiate from micromeres prior to gastrulation. At gastrulation the scleroblasts migrate to the periphery of the embryo and commence spicule deposition around a hexagonal axial filament. Sclerocytes have numerous pseudopodia and migrate to the posterior pole where they become aligned along the antero‐posterior axis in the free‐swimming larva. Reniera larvae possess some 40–50 oxeas, each 70–75 μm long and 1 μm wide. Mature Oopsacas larvae have up to 14 stauractin spicules, which are produced on a rectangular axial filament in tissues that lie under the smooth epithelium at the posterior pole of the larva. Young sclerocytes have many pseudopodia. The 4‐rayed spicules elongate along both the antero‐posterior and medial axes, until the longitudinal rays become anchored in a lipid‐filled cytoplasm at the anterior of the larva and the lateral rays intersect around the midline. The length of the transverse rays of the stauractins in free‐swimming larvae are 27–45 μm each, while the length of the two longitudinal rays is 40–80 μm. Although spicule deposition begins in cells with a similar morphology in both cellular and syncytial sponges, the elaboration and organization of the spicules differ markedly in cellular and syncytial sponges and appear to be an outcome of the very distinct cellular differentiation and larval morphogenesis that occur in each of these groups. Microsc. Res. Tech. 62:300–311, 2003. © 2003 Wiley‐Liss, Inc.
海胆胚胎的骨骼发生。
DOI：
10.1242/dev.103.2.231
发表时间：
1988
期刊：
Development (Cambridge, England)
影响因子：
--
作者：
Decker,GL;Lennarz,WJ
通讯作者：
Lennarz,WJ