@article {69723, title = {The first complete 3D reconstruction and morphofunctional mapping of an insect eye}, year = {2025}, month = {01/2025}, doi = {10.7554/elife.103247.1}, url = {http://dx.doi.org/10.7554/eLife.103247.1}, author = {Makarova, Anastasia A and Chua, Nicholas J and Diakova, Anna V and Desyatirkina, Inna A and Gunn, Pat and Pang, Song and Xu, C Shan and Hess, Harald and Chklovskii, Dmitri B and Polilov, Alexey A} } @article {69022, title = {A complete reconstruction of the early visual system of an adult insect.}, journal = {Current Biology}, volume = {33}, year = {2023}, month = {2023 Nov 06}, pages = {4611-4623}, abstract = {

For most model organisms in neuroscience, research into visual processing in the brain is difficult because of a lack of high-resolution maps that capture complex neuronal circuitry. The microinsect Megaphragma viggianii, because of its small size and non-trivial behavior, provides a unique opportunity for tractable whole-organism connectomics. We image its whole head using serial electron microscopy. We reconstruct its compound eye and analyze the optical properties of the ommatidia as well as the connectome of the first visual neuropil-the lamina. Compared with the fruit fly and the honeybee, Megaphragma visual system is highly simplified: it has 29 ommatidia per eye and 6 lamina neuron types. We report features that are both stereotypical among most ommatidia and specialized to some. By identifying the "barebones" circuits critical for flying insects, our results will facilitate constructing computational models of visual processing in insects.

}, issn = {1879-0445}, doi = {10.1016/j.cub.2023.09.021}, author = {Chua, Nicholas J and Makarova, Anastasia A and Gunn, Pat and Villani, Sonia and Cohen, Ben and Thasin, Myisha and Wu, Jingpeng and Shefter, Deena and Pang, Song and Xu, C Shan and Hess, Harald F and Polilov, Alexey A and Chklovskii, Dmitri B} } @article {68965, title = {Multiscale head anatomy of Megaphragma (Hymenoptera: Trichogrammatidae).}, journal = {Arthropod Structure and Development}, volume = {76}, year = {2023}, month = {2023 Sep 01}, pages = {101299}, abstract = {

Methods of three-dimensional electron microscopy have been actively developed recently and open up great opportunities for morphological work. This approach is especially useful for studying microinsects, since it is possible to obtain complete series of high-resolution sections of a whole insect. Studies on the genus Megaphragma are especially important, since the unique phenomenon of lysis of most of the neuron nuclei was discovered in species of this genus. In this study we reveal the anatomical structure of the head of Megaphragma viggianii at all levels from organs to subcellular structures. Despite the miniature size of the body, most of the organ systems of M.\ viggianii retain the structural plan and complexity of organization at all levels. The set of muscles and the well-developed stomatogastric nervous system of this species correspond to those of larger insects, and there is also a well-developed tracheal system in the head of this species. Reconstructions of the head of M.\ viggianii at the cellular and subcellular levels were obtained, and of volumetric data were analyzed. A total of 689 nucleated cells of the head were reconstructed. The ultrastructure of M.\ viggianii is surprisingly complex, and the evolutionary benefits of such complexity are probably among the factors limiting the further miniaturization of parasitoid wasps.

}, issn = {1873-5495}, doi = {10.1016/j.asd.2023.101299}, author = {Desyatirkina, Inna A and Makarova, Anastasia A and Pang, Song and Xu, C Shan and Hess, Harald and Polilov, Alexey A} } @article {68513, title = {The 3D ultrastructure of the chordotonal organs in the antenna of a microwasp remains complex although simplified.}, journal = {Scientific Reports}, volume = {12}, year = {2022}, month = {2022 Nov 23}, pages = {20172}, abstract = {

Insect antennae are astonishingly versatile and have multiple sensory modalities. Audition, detection of airflow, and graviception are combined in the antennal chordotonal organs. The miniaturization of these complex multisensory organs has never been investigated. Here we present a comprehensive study of the structure and scaling of the antennal chordotonal organs of the extremely miniaturized parasitoid wasp Megaphragma viggianii based on 3D electron microscopy. Johnston{\textquoteright}s organ of M. viggianii consists of 19 amphinematic scolopidia (95 cells); the central organ consists of five scolopidia (20 cells). Plesiomorphic composition includes one accessory cell per scolopidium, but in M. viggianii this ratio is only 0.3. Scolopale rods in Johnston{\textquoteright}s organ have a unique structure. Allometric analyses demonstrate the effects of scaling on the antennal chordotonal organs in insects. Our results not only shed light on the universal principles of miniaturization of sense organs, but also provide context for future interpretation of the M. viggianii connectome.

}, keywords = {Animals, Arthropod Antennae, Insecta, Mechanoreceptors, Microscopy, Electron, Sense Organs}, issn = {2045-2322}, doi = {10.1038/s41598-022-24390-4}, author = {Diakova, Anna V and Makarova, Anastasia A and Pang, Song and Xu, C Shan and Hess, Harald and Polilov, Alexey A} } @article {66901, title = {Protocol for preparation of heterogeneous biological samples for 3D electron microscopy: a case study for insects.}, journal = {Scientific Reports}, volume = {11}, year = {2021}, month = {2021 Feb 25}, pages = {4717}, abstract = {

Modern morphological and structural studies are coming to a new level by incorporating the latest methods of three-dimensional electron microscopy (3D-EM). One of the key problems for the wide usage of these methods is posed by difficulties with sample preparation, since the methods work poorly with heterogeneous (consisting of tissues different in structure and in chemical composition) samples and require expensive equipment and usually much time. We have developed a simple protocol allows preparing heterogeneous biological samples suitable for 3D-EM in a laboratory that has a standard supply of equipment and reagents for electron microscopy. This protocol, combined with focused ion-beam scanning electron microscopy, makes it possible to study 3D ultrastructure of complex biological samples, e.g., whole insect heads, over their entire volume at the cellular and subcellular levels. The protocol provides new opportunities for many areas of study, including connectomics.

}, issn = {2045-2322}, doi = {10.1038/s41598-021-83936-0}, author = {Polilov, Alexey A and Makarova, Anastasia A and Pang, Song and Shan Xu, C and Hess, Harald} }