发现斑马鱼肠道可分为前、中、后三段，肠壁由内向外分为粘膜层、肌层和浆膜层三层。
We found that zebrafish intestine could be divided into three segments : anterior segment , middle segment , posterior segment and its wall was made up of three layers : mucosa , muscularis , and serosa .
三段壁