Learning from the extraordinary: How the highly derived larval eyes of the Sunburst Diving Beetle can give insights into aspects of holometabolous insect visual systems
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| Language: | English |
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University of Cincinnati / OhioLINK
2011
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| Online Access: | http://rave.ohiolink.edu/etdc/view?acc_num=ucin1313495310 |
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ndltd-OhioLink-oai-etd.ohiolink.edu-ucin1313495310 |
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NDLTD |
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English |
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Biology |
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Biology Stecher, Nadine Learning from the extraordinary: How the highly derived larval eyes of the Sunburst Diving Beetle can give insights into aspects of holometabolous insect visual systems |
| author |
Stecher, Nadine |
| author_facet |
Stecher, Nadine |
| author_sort |
Stecher, Nadine |
| title |
Learning from the extraordinary: How the highly derived larval eyes of the Sunburst Diving Beetle can give insights into aspects of holometabolous insect visual systems |
| title_short |
Learning from the extraordinary: How the highly derived larval eyes of the Sunburst Diving Beetle can give insights into aspects of holometabolous insect visual systems |
| title_full |
Learning from the extraordinary: How the highly derived larval eyes of the Sunburst Diving Beetle can give insights into aspects of holometabolous insect visual systems |
| title_fullStr |
Learning from the extraordinary: How the highly derived larval eyes of the Sunburst Diving Beetle can give insights into aspects of holometabolous insect visual systems |
| title_full_unstemmed |
Learning from the extraordinary: How the highly derived larval eyes of the Sunburst Diving Beetle can give insights into aspects of holometabolous insect visual systems |
| title_sort |
learning from the extraordinary: how the highly derived larval eyes of the sunburst diving beetle can give insights into aspects of holometabolous insect visual systems |
| publisher |
University of Cincinnati / OhioLINK |
| publishDate |
2011 |
| url |
http://rave.ohiolink.edu/etdc/view?acc_num=ucin1313495310 |
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AT stechernadine learningfromtheextraordinaryhowthehighlyderivedlarvaleyesofthesunburstdivingbeetlecangiveinsightsintoaspectsofholometabolousinsectvisualsystems |
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1719433442246000640 |
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ndltd-OhioLink-oai-etd.ohiolink.edu-ucin13134953102021-08-03T06:15:05Z Learning from the extraordinary: How the highly derived larval eyes of the Sunburst Diving Beetle can give insights into aspects of holometabolous insect visual systems Stecher, Nadine Biology Stemmata, the eyes of holometabolous insect larvae, vary greatly in number, structure and task. The stemmata of the Sunburst Diving Beetle, Thermonectus marmoratus, are among the most sophisticated. The predatory larvae have six eyes and a potentially light-sensitive spot (eye spot) adjacent to the stemmata. The forward-pointing tubular eyes Eye 1 (E1) and Eye 2 (E2) are involved in prey capture, and possess a biconvex lens, a cellular crystalline cone-like structure, and tiered retinal tissue. A distal and a proximal retina can be distinguished, which differ not only in morphology but possibly also in function. E1 has an additional retina which runs medially alongside the crystalline cone-like structure. Using transmission electron microscopic preparations, I described the ultrastructure of the retinas of the principal eyes E1 and E2. The proximal retinas are composed of photoreceptors with predominantly parallel microvilli, and neighboring rhabdomeres are oriented approximately orthogonally to each another. This rhabdomeric arrangement is typical for eyes that are polarization sensitive. A similar organization is observed in a portion of the medial retina of E1, but not in either of the distal retinas. Since Thermonectus marmoratus larvae are visually-guided predators, polarization sensitivity would perhaps improve their ability to detect prey with polarization features. Measuring hunting performance of larvae under polarized or unpolarized illumination conditions, I have shown that polarized illumination decreased the latency to prey detection and improves capturing success. Although polarization-sensitivity is expected to be common among holometabolous insect larvae due to the rhabdomeric nature of their stemmata, no larvae have been named that possess polarization sensitivity that is involved in prey capture. Moreover, while many invertebrates that are polarization sensitive have polarization-specific regions in their visual system, the eyes of Thermonectus marmoratus larvae potentially have a division of labor within the same stemma. The interesting question arises as to how these stemmata develop.Although they are structurally very unlike each other, stemmata are considered to be homologous to adult compound eyes. It is perhaps in their development that one can find evidence for a common ancestry. Using basic histological methods, I observed stemmatal development in Thermonectus marmoratus embryos, and contrasted my finding to structural changes during compound eye development. The latter is described best in Drosophila. Similar to Drosophila ommatidia, the stemmata originate from a proliferative, pseudostratified epithelium. The photoreceptor cells differentiate in sequence, and they appear before the accessory cells differentiate. In Thermonectus marmoratus, the photoreceptor cells that are located in the proximal layer in the fully-developed stemma assume their position earlier than the prospective distal photoreceptors. In contrast to the Drosophila compound eye, which is characterized by distinct periods of high mitotic activity, cell proliferation in T. marmoratus stemmatal development appears to be a continuous but low-level process. Moreover, I did not observe a morphogenetic furrow-like differentiation process such as it is typical for Drosophila ommatidial development. Based on the morphological study, it will be possible to investigate molecular similarities between the development of compound eyes in Drosophila and the stemmata in Thermonectus marmoratus. 2011-09-23 English text University of Cincinnati / OhioLINK http://rave.ohiolink.edu/etdc/view?acc_num=ucin1313495310 http://rave.ohiolink.edu/etdc/view?acc_num=ucin1313495310 unrestricted This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws. |