Grimaldi Annalisa, Tettamanti Gianluca, Brivio Maurizio F, Valvassori Roberto, De Eguileor Magda
Department of Structural and Functional Biology, University of Insubria, Via J. H. Dunant 3, 21100 Varese, Italy.
Dev Growth Differ. 2004 Apr;46(2):181-93. doi: 10.1111/j.1440-169X.2004.00738.x.
The tentacles of Sepia officinalis are cylindrical muscular structures that can be quickly everted and elongated to capture prey. The combination of both velocity and extensive elongation of the tentacles is due to the presence of both cross-striated and helical muscles. The complex organization and differentiation of different fibers has been studied in cuttlefish extracted from egg gel coats at different developmental stages, and in completely developed animals. Tentacle muscles start to differentiate centrifugally from the area close to the axial nervous system, where two types of myocytes can be recognized. These populations of myocytes, which may be distinguished morphologically and which express different myosin isoforms, give rise to fast and slow muscles. The presence in molluscs of slow and fast muscles arising from different populations of myocytes, as in vertebrate muscle development, could be considered as an example of evolutionary conservation.
乌贼的触手是圆柱形的肌肉结构，能够快速外翻并伸长以捕获猎物。触手的速度和广泛伸长是由于横纹肌和螺旋肌的共同存在。不同纤维的复杂组织和分化已在不同发育阶段从卵凝胶外套中提取的乌贼以及完全发育的动物中进行了研究。触手肌肉从靠近轴向神经系统的区域开始离心分化，在该区域可以识别出两种类型的肌细胞。这些在形态上可区分且表达不同肌球蛋白同工型的肌细胞群体，产生了快肌和慢肌。在软体动物中，如同在脊椎动物肌肉发育中一样，由不同肌细胞群体产生的慢肌和快肌的存在，可以被视为进化保守性的一个例子。
