Hyperspectral topography of the twisted, cholesteric patterns of an insect cuticle under various conditions of helix obliquity

Aurélie Jullien; Maxim Neradovskiy; Michel Mitov

doi:10.1063/5.0019039

Reconstruction of Chitin-Protein Complexes Using Correlation Averaging Methods: Ovipositor of the Ichneumon Fly Megarhyssa

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s1431927600000143 ◽

1980 ◽

Vol 38 ◽

pp. 38-39

Author(s):

L. T. Germinario ◽

J. Blackwell ◽

J. Frank

Keyword(s):

Protein Complexes ◽

Hexagonal Lattice ◽

Uranyl Acetate ◽

Optical Diffraction ◽

Insect Cuticle ◽

High Dose ◽

Wide Angle ◽

X Ray ◽

Averaging Methods ◽

Digital Correlation

This report describes the use of digital correlation and averaging methods 1,2 for the reconstruction of high dose electron micrographs of the chitin-protein complex from Megarhyssa ovipositor. Electron microscopy of uranyl acetate stained insect cuticle has demonstrated a hexagonal array of unstained chitin monofibrils, 2.4−3.0 nm in diameter, in a stained protein matrix3,4. Optical diffraction Indicated a hexagonal lattice with a = 5.1-8.3 nm3 A particularly well ordered complex is found in the ovipositor of the ichneumon fly Megarhyssa: the small angle x-ray data gives a = 7.25 nm, and the wide angle pattern shows that the protein consists of subunits arranged in a 61 helix, with an axial repeat of 3.06 nm5.

Download Full-text

Biomechanics of insect cuticle: an interdisciplinary experimental challenge

Applied Physics A ◽

10.1007/s00339-021-04439-3 ◽

2021 ◽

Vol 127 (5) ◽

Author(s):

Karen Stamm ◽

Brian Daniel Saltin ◽

Jan-Henning Dirks

Keyword(s):

Meta Analysis ◽

Biomechanical Properties ◽

Measurement Methods ◽

Insect Cuticle ◽

Body Parts ◽

Scientific Methods ◽

Advantages And Disadvantages ◽

Examination Techniques ◽

Evolutionary Success ◽

Experimental Challenge

AbstractThe cuticle exoskeleton plays a key role in facilitating the evolutionary success of insects. Since the mid of the last century, many different biomechanical properties of exoskeletons have been investigated, always utilizing the most sophisticated scientific methods available at the time. So far, information on the biomechanical properties of cuticle seems to be as diverse as the methods used to measure them. As a consequence, insect cuticle is often considered to exhibit the most complex and diverse biomechanical properties of any biological material. However, it remains unclear which role the respective measurement methods and sample treatments used in previous studies play in supporting this claim. This review provides a broad overview of examination techniques used to study biomechanical properties of insect exoskeletons and discusses their respective advantages and disadvantages in describing the properties of a complex material such as cuticle. Our meta-analysis of the present data confirms significant effects of the respective measurement methods, sample treatments and body parts on the obtained mechanical properties. Based on our findings, we highlight research gaps and point out important factors which should be taken into account in future studies on insect cuticle.

Download Full-text

MrpacC regulates sporulation, insect cuticle penetration and immune evasion inMetarhizium robertsii

Environmental Microbiology ◽

10.1111/1462-2920.12451 ◽

2014 ◽

Vol 17 (4) ◽

pp. 994-1008 ◽

Cited By ~ 44

Author(s):

Wei Huang ◽

Yanfang Shang ◽

Peilin Chen ◽

Qiang Gao ◽

Chengshu Wang

Keyword(s):

Immune Evasion ◽

Insect Cuticle

Download Full-text

Synthesis ofN-Acetyl-1,2-didehydrodopamine. A Key Intermediate Involved in Sclerotization of Insect Cuticle

Synthesis ◽

10.1055/s-1987-27993 ◽

1987 ◽

Vol 1987 (05) ◽

pp. 523-524 ◽

Cited By ~ 15

Author(s):

B. Ramamurthy ◽

M. Sugumaran

Keyword(s):

Insect Cuticle

Download Full-text

Classification and infection mechanism of entomopathogenic fungi

Arquivos do Instituto Biológico ◽

10.1590/1808-1657000552015 ◽

2018 ◽

Vol 84 (0) ◽

Cited By ~ 10

Author(s):

Margy Alejandra Esparza Mora ◽

Alzimiro Marcelo Conteiro Castilho ◽

Marcelo Elias Fraga

Keyword(s):

Biological Control ◽

Entomopathogenic Fungi ◽

Mode Of Action ◽

Insect Cuticle ◽

Biological Control Agents ◽

Intensive Research ◽

Infection Mechanism ◽

The World ◽

The Subject

ABSTRACT: Entomopathogenic fungi are important biological control agents throughout the world, have been the subject of intensive research for more than 100 years, and can occur at epizootic or enzootic levels in their host populations. Their mode of action against insects involves attaching a spore to the insect cuticle, followed by germination, penetration of the cuticle, and dissemination inside the insect. Strains of entomopathogenic fungi are concentrated in the following orders: Hypocreales (various genera), Onygenales (Ascosphaera genus), Entomophthorales, and Neozygitales (Entomophthoromycota).

Download Full-text