Semino C E, Allende M L
Center for Cancer Research, Massachusetts Institute of Technology, Cambridge, USA.
Int J Dev Biol. 2000 Feb;44(2):183-93.
In this work we investigate the possible function of N-acetyl-chitooligosaccharides (NACOs) produced during zebrafish (Danio rerio) development. First, we show that NACOs are synthesized in vivo during early embryogenesis in the zebrafish. Second, we demonstrate that injection of a pure bacterial chitinase into one-cell stage embryos elicits developmental defects in which the posterior trunk and tail of developing embryo are severely affected. In addition, an endogenous chitinase activity detected both intra- and extracellularly is described, suggesting that cells may secrete it into the extracellular space. Moreover, this compartmentalization appears to be functionally relevant as inhibition of the extracellular, but not the intracellular, endogenous chitinase activity causes morphological defects similar to those seen in embryos injected with chitinase 63. Finally, analysis of the expression of the zebrafish ZDG42 gene, which has been suggested to be involved in synthesis of NACOs, is described. Transcripts are detected from late blastula stage, during gastrulation, and move as an anterior-posterior wave of expression in adaxial mesoderm during somitogenesis.
在这项工作中，我们研究了斑马鱼（Danio rerio）发育过程中产生的N - 乙酰壳寡糖（NACOs）的可能功能。首先，我们表明NACOs是在斑马鱼早期胚胎发育过程中在体内合成的。其次，我们证明向单细胞期胚胎注射纯细菌几丁质酶会引发发育缺陷，其中发育中胚胎的后躯干和尾巴受到严重影响。此外，还描述了在细胞内和细胞外均检测到的内源性几丁质酶活性，这表明细胞可能将其分泌到细胞外空间。而且，这种区室化似乎在功能上具有相关性，因为抑制细胞外而非细胞内的内源性几丁质酶活性会导致与注射几丁质酶63的胚胎中所见相似的形态缺陷。最后，描述了对斑马鱼ZDG42基因表达的分析，该基因被认为参与NACOs的合成。转录本在囊胚后期、原肠胚形成期间被检测到，并在体节形成期间作为表达的前后波在近轴中胚层中移动。
