Wanninger A, Ruthensteiner B, Lobenwein S, Salvenmoser W, Dictus W J, Haszprunar G
Zoologische Staatssammlung, Münchhausenstrasse 21, D-81247 München, Germany.
Dev Genes Evol. 1999 Apr;209(4):226-38. doi: 10.1007/s004270050247.
Whole-mount technique using fluorescent-labelled phalloidin for actin staining and confocal laser scanning microscopy as well as semi-thin serial sectioning, scanning and transmission electron microscopy were applied to investigate the ontogeny of the various muscular systems during larval development in the limpets Patella vulgata L. and P. caerulea L. In contrast to earlier studies, which described a single or two larval shell muscles, the pretorsional trochophore-like larva shows no less than four different muscle systems, namely the asymmetrical main head/foot larval retractor muscle, an accessory larval retractor with distinct insertion area, a circular prototroch/velar system, and a plexus-like pedal muscle system. In both Patella species only posttorsional larvae are able to retract into the shell and to close the aperture by means of the operculum. Shortly after torsion the two adult shell muscles originate independently in lateral positions, starting with two fine muscle fibres which insert at the operculum and laterally at the shell. During late larval development the main larval retractor and the accessory larval retractor become reduced and the velar muscle system is shed. In contrast, the paired adult shell muscles and the pedal muscle plexus increase in volume, and a new mantle musculature, the tentacular muscle system, and the buccal musculature arise. Because the adult shell muscles are entirely independent from the various larval muscular systems, several current hypotheses on the ontogeny and phylogeny of the early gastropod muscle system have to be reconsidered.
采用荧光标记鬼笔环肽进行肌动蛋白染色的整体装片技术、共聚焦激光扫描显微镜以及半薄连续切片、扫描和透射电子显微镜，用于研究笠贝Patella vulgata L.和P. caerulea L.幼虫发育过程中各种肌肉系统的个体发生。与早期研究不同，早期研究描述了一或两条幼虫壳肌，而扭转前类似担轮幼虫的幼虫显示出不少于四种不同的肌肉系统，即不对称的主要头/足幼虫牵缩肌、具有不同插入区域的辅助幼虫牵缩肌、环形原纤毛/缘膜系统以及丛状足肌系统。在这两种笠贝中，只有扭转后的幼虫能够缩入壳内并通过厣关闭壳口。扭转后不久，两条成体壳肌在外侧独立起源，起始于两条细肌纤维，它们插入厣并在壳的外侧附着。在幼虫发育后期，主要幼虫牵缩肌和辅助幼虫牵缩肌变小，缘膜肌肉系统脱落。相反，成对的成体壳肌和足肌丛体积增大，新的外套膜肌肉组织、触手肌肉系统和颊部肌肉组织出现。由于成体壳肌完全独立于各种幼虫肌肉系统，因此必须重新考虑目前关于早期腹足类肌肉系统个体发生和系统发育的几种假说。
