Shostak Stanley
Department of Biological Sciences, University of Pittsburgh, 15260, Pittsburgh, Pennsylvania, USA.
Wilehm Roux Arch Dev Biol. 1981 Sep;190(5):274-282. doi: 10.1007/BF00848755.
YoungBunodactis verrucosa Pennant at the 12 tentacle stage are employed to test the applicability of the polar coordinate model to coelenterate regeneration. The animals are cut along every radius into fragments of 3 to 9 segments. Most fragments are patent 3-4 weeks later, but small fragments have a higher mortality rate than large fragments. Some fragments do not regenerate and occasionally tentacles fuse, thereby reducing the number of segments. Small fragments tend to regenerate more tentacies than large fragments, but large fragments may regenerate great numbers of supernumerary tentacles. Twenty-two percent of the fragments restore the missing number of tentacles, while 76% of all fragments produce an even number of tentacles.Fragments restoring the correct numbers of tentacles show a marked tendency to form the correct tentacles (regulative regeneration). Fragments regenerating two less than the number of tentacles already present show a marked tendency to reproduce tentacles of the types already present (miror image formation). Other fragments produce missing segments (forward regeneration), or those already present (reverse regeneration) at lower frequencies.No fragments beginning or ending with the number 1 directive tentacle fail to regenerate entirely, while first cycle segments maximally remote from segment 1 are associated with the absence of regeneration. No fragments beginning or ending with the number 4 directive tentacle fail to undergo forward regeneration, regulate or produce a mirror image when the appropriate number of segments are regenerated. In contrast, segment 4 is associated with a low frequency of reverse regeneration, and second cycle segments cut away from immediate contact with segment 4 show an increase in the frequency of reverse regeneration. Controls through morphogenic substances rather than polar coordinates seem to explain these results. Such substances would control the number and direction of tentacle regeneration.
处于12触手阶段的疣海葵被用于测试极坐标模型对腔肠动物再生的适用性。将这些动物沿每条半径切成3至9段的碎片。大多数碎片在3至4周后存活，但小碎片的死亡率高于大碎片。一些碎片不进行再生，触手偶尔会融合，从而减少段数。小碎片往往比大碎片再生出更多的触手，但大碎片可能再生出大量多余的触手。22%的碎片恢复了缺失的触手数量，而所有碎片中有76%产生偶数个触手。恢复正确触手数量的碎片显示出形成正确触手的明显趋势（调节性再生）。再生的触手比已有的触手数量少两个的碎片显示出明显的趋势，即再生已有的触手类型（镜像形成）。其他碎片以较低频率产生缺失的段（正向再生）或已有的段（反向再生）。没有以1号指令触手开始或结束的碎片完全不能再生，而离1号段最远的第一周期段与再生缺失有关。没有以4号指令触手开始或结束的碎片在再生出适当数量的段时不能进行正向再生、调节或产生镜像。相比之下，4号段与反向再生的低频率相关，与4号段直接接触被切断的第二周期段显示出反向再生频率的增加。通过形态发生物质而非极坐标进行控制似乎可以解释这些结果。这些物质将控制触手再生的数量和方向。
