Shepherd I T, Raper J A
Department of Neurosciences, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, 19104, USA.
Dev Biol. 1999 Aug 1;212(1):42-53. doi: 10.1006/dbio.1999.9294.
Chick collapsin-1/human semaphorin III/mouse semaphorin D is believed to guide the extension of specific axons by a repellent mechanism. Here we examine its role in the guidance of axons of the ganglion of Remak (Remak) in the developing chick intestine. Early in embryogenesis Remak axons extend parallel to, but do not enter, the intestine when collapsin-1 is expressed in the adjacent rectal wall. Remak axons later penetrate the peripheral portions of the rectal wall when collapsin-1 expression retreats from the outer muscle layer to the more internal submucosal and mucosal layers of the rectum. Extension of Remak neurites is repelled in vitro by rectum explants and also by 293T cells expressing collapsin-1. The rectal chemorepellent activity is blocked by anti-collapsin-1 antibodies. Our results suggest that collapsin-1 may help prevent Remak axons from projecting into the intestinal wall at early developmental times and later restricts Remak axon trajectories to the outer part of the intestinal muscle layer.
鸡的塌陷素-1/人信号素III/小鼠信号素D被认为通过一种排斥机制引导特定轴突的延伸。在此，我们研究其在发育中的鸡肠道里雷马克神经节（Remak）轴突导向中的作用。在胚胎发育早期，当塌陷素-1在相邻的直肠壁中表达时，雷马克轴突平行于肠道延伸，但不进入肠道。当塌陷素-1的表达从直肠外肌层退至直肠更内侧的黏膜下层和黏膜层时，雷马克轴突随后穿透直肠壁的外周部分。在体外，雷马克神经突的延伸受到直肠外植体以及表达塌陷素-1的293T细胞的排斥。直肠化学排斥活性被抗塌陷素-1抗体阻断。我们的结果表明，塌陷素-1可能有助于在发育早期防止雷马克轴突伸入肠壁，随后将雷马克轴突的轨迹限制在肠肌层的外部。
