Checa Antonio G, Linares Fátima, Grenier Christian, Griesshaber Erika, Rodríguez-Navarro Alejandro B, Schmahl Wolfgang W
Departamento de Estratigrafía y Paleontología, Universidad de Granada, 18071 Granada, Spain.
Instituto Andaluz de Ciencias de la Tierra, CSIC-Universidad de Granada, 18100 Armilla, Spain.
iScience. 2021 Oct 15;24(11):103288. doi: 10.1016/j.isci.2021.103288. eCollection 2021 Nov 19.
The shell of the cephalopod consists of two layers of fibers that elongate perpendicular to the shell surfaces. Fibers have a high-Mg calcitic core sheathed by thin organic membranes (>100 nm) and configurate a polygonal network in cross section. Their evolution has been studied by serial sectioning with electron microscopy-associated techniques. During growth, fibers with small cross-sectional areas shrink, whereas those with large sections widen. It is proposed that fibers evolve as an emulsion between the fluid precursors of both the mineral and organic phases. When polygons reach big cross-sectional areas, they become subdivided by new membranes. To explain both the continuation of the pattern and the subdivision process, the living cells from the mineralizing tissue must perform contact recognition of the previously formed pattern and subsequent secretion at sub-micron scale. Accordingly, the fabrication of the argonaut shell proceeds by physical self-organization together with direct cellular activity.
头足类动物的外壳由两层垂直于壳表面伸长的纤维组成。纤维具有由薄有机膜（>100纳米）包裹的高镁方解石核心，在横截面上构成多边形网络。通过与电子显微镜相关的技术进行连续切片研究了它们的演化过程。在生长过程中，横截面积小的纤维会收缩，而横截面积大的纤维会变宽。有人提出，纤维是作为矿物相和有机相的流体前体之间的乳液演化而来的。当多边形达到大的横截面积时，它们会被新的膜细分。为了解释图案的延续和细分过程，矿化组织中的活细胞必须在亚微米尺度上进行对先前形成图案的接触识别和随后的分泌。因此，船蛸外壳的形成是通过物理自组织以及直接的细胞活动进行的。
