Strus Jasna, Klepal Waltraud, Repina Janja, Tusek-Znidaric Magda, Milatovic Masa, Pipan Ziva
University of Ljubljana, Department of Biology, Vecna pot 111, SI-1000 Ljubljana, Slovenia.
Arthropod Struct Dev. 2008 Jul;37(4):287-98. doi: 10.1016/j.asd.2007.11.004. Epub 2008 Jan 11.
Microscopic anatomy of the digestive system in embryos and larvae of the terrestrial isopod crustacean Porcellio scaber was investigated by light bright field, fluorescence and electron microscopy. During marsupial ontogenetic development the event-dependent staging was used to discriminate the various embryonic stages. At the late embryo stage the differentiation of the ectodermal part of the gut into the complex filtering foregut and the hindgut with absorptive and transporting functions is accomplished. The gut of the marsupial manca larva is fully developed and similar to that of the adult. In early embryos the endodermal midgut gland primordia are filled with yolk and lipid globules. In late embryos the epithelium of paired midgut gland tubes is composed of two cell types; one of them exhibits orange autofluorescence. The endodermal cells located between the foregut and the midgut glands of late embryos form the prospective midgut. The cells have electron dense cytoplasm, abundant glycogen fields, endoplasmic reticulum, dictyosomes and numerous vesicles. In the adults the endodermal cells of the midgut remain only in the midgut gland ducts which connect the midgut glands and the foregut. Details of the cellular ultrastructure and morphogenesis of the ectodermal and endodermal parts of the digestive system during embryonic development of Porcellio scaber provide data for further phylogenetic and comparative studies in peracaridan crustaceans and other arthropods.
通过光学明场、荧光和电子显微镜对陆生等足类甲壳动物粗糙鼠妇胚胎和幼虫消化系统的微观解剖结构进行了研究。在有袋发育过程中，根据发育事件进行分期以区分不同的胚胎阶段。在胚胎后期，肠道外胚层部分分化为复杂的过滤前肠和具有吸收和运输功能的后肠。有袋幼体的肠道已完全发育，与成体相似。在早期胚胎中，内胚层中肠腺原基充满卵黄和脂滴。在晚期胚胎中，成对的中肠腺管上皮由两种细胞类型组成；其中一种呈现橙色自发荧光。晚期胚胎前肠和中肠腺之间的内胚层细胞形成未来的中肠。这些细胞具有电子致密的细胞质、丰富的糖原区域、内质网、高尔基体和大量小泡。在成体中，中肠的内胚层细胞仅保留在连接中肠腺和前肠的中肠腺导管中。粗糙鼠妇胚胎发育过程中消化系统外胚层和内胚层部分的细胞超微结构和形态发生细节为进一步研究十足目甲壳动物和其他节肢动物的系统发育和比较研究提供了数据。
