Crotwell Patricia L, Mabee Paula M
Department of Biology, University of South Dakota, Vermillion, South Dakota 57069, USA.
Dev Dyn. 2007 Nov;236(11):3111-28. doi: 10.1002/dvdy.21352.
Timing and pattern of expression of ten candidate segmentation genes or gene pairs were reviewed or examined in developing median fins of late-stage zebrafish, Danio rerio. We found a general correspondence in timing and pattern of expression between zebrafish fin radial segmentation and tetrapod joint development, suggesting that molecular mechanisms underlying radial segmentation have been conserved over 400 million years of evolution. Gene co-expression during segmentation (5.5-6.5 mm SL) is similar between tetrapods and zebrafish: bmp2b, bmp4, chordin, and gdf5 in interradial mesenchyme and ZS; bapx1, col2a1, noggin3, and sox9a in chondrocytes. Surprisingly, wnt9a is not expressed in the developing median fins, though wnt9b is detected. In contrast to all other candidate segmentation genes we examined, bapx1 is not expressed in the caudal fin, which does not segment. Together, these data suggest a scenario of gene interactions underlying radial segmentation based on the patterns and timing of candidate gene expression.
我们回顾或检测了斑马鱼（Danio rerio）晚期发育中的中鳍中十个候选分割基因或基因对的表达时间和模式。我们发现斑马鱼鳍条径向分割与四足动物关节发育在表达时间和模式上存在普遍对应关系，这表明径向分割的分子机制在超过4亿年的进化过程中得以保留。四足动物和斑马鱼在分割过程中（体长5.5 - 6.5毫米）的基因共表达情况相似：在鳍条间充质和ZS中表达bmp2b、bmp4、chordin和gdf5；在软骨细胞中表达bapx1、col2a1、noggin3和sox9a。令人惊讶的是，尽管检测到wnt9b，但wnt9a在发育中的中鳍中不表达。与我们检测的所有其他候选分割基因不同，bapx1在不分节的尾鳍中不表达。综合这些数据，基于候选基因表达的模式和时间，提出了一种径向分割背后的基因相互作用模式。
