摘要
采用常规孵化的中华鳖胚胎为材料 ,对不同发育时期造血和免疫器官进行了组织学研究 ,描述了卵黄囊、胸腺、肝、脾、肾以及骨髓的形态结构变化。发现胚胎期首先出现的造血器官是卵黄囊。此后 ,卵黄囊的造血干细胞出现在胚体的血循环中 ,造血功能相继在胚胎胸腺、肝、脾、骨髓 (可能还包括肾 )中产生。胸腺是中华鳖免疫系统发育的第一个淋巴器官 ,来自卵黄囊的干细胞在此先分化成小淋巴细胞 ,然后再迁移至脾脏。脾脏发育中首先出现各发育阶段的红细胞、嗜酸性的细胞和少量粒细胞 ,淋巴细胞出现较晚 ,未发现淋巴小结。在胚胎期肝脏发育过程中可见不同发育时期的红细胞和嗜酸性的细胞。在肾的发育过程中 ,尚可观察到嗜酸性的细胞和类似头肾组织的细胞团。直至出壳前 。
The ontogeny of hemopoietic and immune organs in the Chinese soft shelled turtl e, Trionyx sinensis , was studied and the morphological characteristics of tw o to three embryos from each embryonic stage described with histological examination . The first hemopoietic organ in embryos was the yolk sac. Later in development, hemopoietic stem cells in the yolk sac migrate via blood vessels and yolk sac h emopoietic activity is succeeded by development of the fetal thymus, liver, sple en and bone marrow (possibly kidney). Hemopoiesis was detected in the yolk sac a t stage 6 after incubation. Hemopoietic stem cells were small, with an oval nucl eus surrounded by a thin rim of basophilic cytoplasm. In addition, different dev elopmental stages of erythrocytes were observed. The primordial thymus appeared at stage 14 as a detectable thickening of the posterioventral wall of the pharyn geal pouch Ⅲ. The dorsal portion of the thickening gave rise to the thymic prim ordium, whereas the ventral part became the parathyroid rudiment. By stage 16, t he thymus rudiments were more defined, were closely situated near the internal jugular vein in which there were a large num ber of stem like cells and appeared as a condensation of epithelial cells surro u nded by mesenchyme. By stage 19, the thymus lobes were distinctly encapsulated a nd contained numerous small basophilic cells as well as lymphocytes among the ep ithelial cells. Until stage 25, complete demarcation of cortex and medulla was a pparent. During the course of embryonic development, the thymus and parathyroid rudiments migrated ventrocaudally. The parathyroid glands were surrounded by thy mus tissue because the thymus didnt enter into the chest cavity. The thymus is the first lymphoid organ in embryonic development. Within the thymus, stem cell s from the yolk sac differentiate into small lymphocytes which subsequently migr ate to the spleen. The histogenesis of the spleen commenced with a thickening o f the dorsal mesogastrium. By stage 15-16, the splenic rudime
出处
《动物学报》
SCIE
CAS
CSCD
北大核心
2003年第2期238-247,共10页
ACTA ZOOLOGICA SINICA
基金
国家自然科学基金 (No .3 0 0 70 5 88)
中国科学院所长择优基金资助项目~~
