Three-dimensional reconstruction on cell level: case study elucidates the ultrastructure of the spinning apparatus of Embia sp. (Insecta: Embioptera)

Abstract

Spinning is a phenomenon not only present in spiders, but also in many other arthropods. The functional morphology and complexity of spinning organs is often poorly understood. Their elements are minute and studying them poses substantial methodological difficulties. This study presents a three-dimensional reconstruction of a silk gland of Embia sp. on cellular level, based on serial sections acquired with serial block-face scanning electron microscopy (SBFSEM) to showcase the power of this method. Previous studies achieved either high resolution to elucidate the ultrastructure or satisfying three-dimensional representations. The high-resolution achieved by SBFSEM can be easily used to reconstruct the three-dimensional ultrastructural organization of cellular structures. The herein investigated spinning apparatus of Embioptera can be taken as an example demonstrating the potential of this method. It was possible to reconstruct a multinucleated silk gland containing 63 nuclei. We focused on the applicability of this method in the field of morphological research and provide a step-by-step guide to the methodology. This will help in applying the method to other arthropod taxa and will help significantly in adapting the method to other animals, animal parts and tissues.

A general theory of genital homologies for the Hexapoda (Pancrustacea) derived from skeletomuscular correspondences, with emphasis on the Endopterygota

“…The process of generating these phenotypic data from observations is greatly facilitated by ontologies (e.g., Yoder et al, 2010;HAO, 2016;Wirkner et al, 2017). Ontologies may further be useful for training a machinelearning program (e.g., Jones, 2014;Maxmen, 2017, others) to generate data from three-dimensional m-CT models (e.g., Büsse et al, 2016;Polilov, 2011Polilov, , 2015; see also Beutel et al, 2014, chapter 4). Beyond improving visual communication of morphological observations (e.g., Hendricks et al, 2018a, b), integration of the methodologies addressed above may allow us to critically watch as we replay life's tape in three dimensions.…”

Rayos X y resonancia magnética en la entomología: principios y aplicaciones

“…Otra metodología que permite estudiar la anatomía y morfología del cuerpo completo o secciones de interés de los insectos es la reconstrucción digital de modelos en 3D, la cual facilita el estudio en diversas áreas de la entomología como en sistemática, taxonomía, estudios del desarrollo ontogénico, análisis funcionales y procesos evolutivos (Triplehorn y Johnson, 2005;Betz et al, 2007;Büsse et al, 2015;Büsse et al, 2016;Ijiri et al, 2018;Bukejs et al, 2020).…”

“…La µCT de alta resolución permite reconstruir modelos en 3D de estructuras externas e internas (Büsse et al, 2016). Este tipo de imagenología es de gran apoyo para esquematizar y mejorar la comprensión del desarrollo y anatomía de los insectos (Bukejs et al, 2020).…”

Investigation of spatial nano-structure development of the hardened C3S pastes by serial block-face SEM

“…Every time the sample is cut, the newly exposed surface is imaged by using back-scattered electron signals, and then a new cut will be performed again. This process is automatically performed continuously according to the set parameters [26,27]. The 3D image is then obtained by stacking the serial slice images together.…”