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Currea JP, Sondhi Y, Kawahara AY, Theobald J. Measuring compound eye optics with microscope and microCT images. Commun Biol 2023; 6:246. [PMID: 36882636 PMCID: PMC9992655 DOI: 10.1038/s42003-023-04575-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Accepted: 02/10/2023] [Indexed: 03/09/2023] Open
Abstract
With a great variety of shapes and sizes, compound eye morphologies give insight into visual ecology, development, and evolution, and inspire novel engineering. In contrast to our own camera-type eyes, compound eyes reveal their resolution, sensitivity, and field of view externally, provided they have spherical curvature and orthogonal ommatidia. Non-spherical compound eyes with skewed ommatidia require measuring internal structures, such as with MicroCT (µCT). Thus far, there is no efficient tool to characterize compound eye optics, from either 2D or 3D data, automatically. Here we present two open-source programs: (1) the ommatidia detecting algorithm (ODA), which measures ommatidia count and diameter in 2D images, and (2) a µCT pipeline (ODA-3D), which calculates anatomical acuity, sensitivity, and field of view across the eye by applying the ODA to 3D data. We validate these algorithms on images, images of replicas, and µCT eye scans from ants, fruit flies, moths, and a bee.
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Affiliation(s)
- John Paul Currea
- Integrative Biology and Physiology, UCLA, Los Angeles, CA, 90095, USA.
| | - Yash Sondhi
- Department of Biological Sciences, Florida International University, Miami, FL, 33199, USA
- McGuire Center for Lepidoptera and Biodiversity, Florida Museum of Natural History, University of Florida, Gainesville, FL, 32611, USA
| | - Akito Y Kawahara
- McGuire Center for Lepidoptera and Biodiversity, Florida Museum of Natural History, University of Florida, Gainesville, FL, 32611, USA
| | - Jamie Theobald
- Department of Biological Sciences, Florida International University, Miami, FL, 33199, USA.
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2
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Tichit P, Zhou T, Kjer HM, Dahl VA, Dahl AB, Baird E. InSegtCone: interactive segmentation of crystalline cones in compound eyes. BMC ZOOL 2022; 7:10. [PMID: 37170292 PMCID: PMC10127308 DOI: 10.1186/s40850-021-00101-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 12/14/2021] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Understanding the diversity of eyes is crucial to unravel how different animals use vision to interact with their respective environments. To date, comparative studies of eye anatomy are scarce because they often involve time-consuming or inefficient methods. X-ray micro-tomography (micro-CT) is a promising high-throughput imaging technique that enables to reconstruct the 3D anatomy of eyes, but powerful tools are needed to perform fast conversions of anatomical reconstructions into functional eye models.
Results
We developed a computing method named InSegtCone to automatically segment the crystalline cones in the apposition compound eyes of arthropods. Here, we describe the full auto-segmentation process, showcase its application to three different insect compound eyes and evaluate its performance. The auto-segmentation could successfully label the full individual shapes of 60-80% of the crystalline cones and is about as accurate and 250 times faster than manual labelling of the individual cones.
Conclusions
We believe that InSegtCone can be an important tool for peer scientists to measure the orientation, size and dynamics of crystalline cones, leading to the accurate optical modelling of the diversity of arthropod eyes with micro-CT.
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3
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Perl CD, Johansen ZB, Moradinour Z, Guiraud M, Restrepo CE, Wen Jie V, Miettinen A, Baird E. Heatwave-Like Events During Development Are Sufficient to Impair Bumblebee Worker Responses to Sensory Stimuli. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2021.776830] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Heatwaves are increasingly common globally and are known to have detrimental impacts on animal morphology and behaviour. These impacts can be severe, especially if heatwaves occur during development, even on animals that can regulate the temperature of their developing young. The onset and duration of heatwaves are stochastic and therefore may affect all or only part of development. In the heterothermic bumblebee Bombus terrestris, elevated temperatures over the entirety of development cause morphological changes in adults, despite their capability to regulate brood temperature. However, the effects of heatwaves that occur during a short period of development are unclear. We test the impact of elevated developmental temperature during the latter fraction of development on the behaviour and morphology of adult worker B. terrestris. We show that exposure to elevated temperature over a portion of late development is sufficient to impair the initial behavioural responses of workers to various sensory stimuli. Despite this, exposure to elevated temperatures during a period of development did not have any significant impact on body or organ size. The negative effect of elevated developmental temperatures was independent of the exposure time, which lasted from 11–20 days at the end of the workers’ developmental period. Thus, heat stress in bumblebees can manifest without morphological indicators and impair critical behavioural responses to relevant sensory stimuli, even if only present for a short period of time at the end of development. This has important implications for our understanding of deleterious climactic events and how we measure indicators of stress in pollinators.
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Perl CD, Johansen ZB, Jie VW, Moradinour Z, Guiraud M, Restrepo CE, Miettinen A, Baird E. Substantial variability in morphological scaling among bumblebee colonies. ROYAL SOCIETY OPEN SCIENCE 2022; 9:211436. [PMID: 35242346 PMCID: PMC8753140 DOI: 10.1098/rsos.211436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Accepted: 12/14/2021] [Indexed: 06/14/2023]
Abstract
Differences in organ scaling among individuals may play an important role in determining behavioural variation. In social insects, there are well-documented intraspecific differences in colony behaviour, but the extent that organ scaling differs within and between colonies remains unclear. Using 12 different colonies of the bumblebee Bombus terrestris, we aim to address this knowledge gap by measuring the scaling relationships between three different organs (compound eyes, wings and antennae) and body size in workers. Though colonies were exposed to different rearing temperatures, this environmental variability did not explain the differences of the scaling relationships. Two colonies had differences in wing versus antenna slopes, three colonies showed differences in wing versus eye slopes and a single colony has differences between eye versus antenna slopes. There are also differences in antennae scaling slopes between three different colonies, and we present evidence for putative trade-offs in morphological investment. We discuss the utility of having variable scaling among colonies and the implication for understanding variability in colony fitness and behaviour.
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Affiliation(s)
- C. D. Perl
- Department of Zoology, Stockholm University, Stockholm 106 91, Sweden
- Department of Biology, Lund University, Lund 223 62, Sweden
| | - Z. B. Johansen
- Department of Zoology, Stockholm University, Stockholm 106 91, Sweden
| | - V. W. Jie
- Department of Zoology, Stockholm University, Stockholm 106 91, Sweden
| | - Z. Moradinour
- Department of Zoology, Stockholm University, Stockholm 106 91, Sweden
| | - M. Guiraud
- Department of Zoology, Stockholm University, Stockholm 106 91, Sweden
| | - C. E. Restrepo
- Department of Zoology, Stockholm University, Stockholm 106 91, Sweden
| | - A. Miettinen
- Swiss Light Source, Paul Scherrer Institute, 5234 Villigen, Switzerland
- Institute for Biomedical Engineering, University and ETH Zurich, 8092 Zurich, Switzerland
| | - E. Baird
- Department of Zoology, Stockholm University, Stockholm 106 91, Sweden
- Department of Biology, Lund University, Lund 223 62, Sweden
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Rigosi E, Warrant EJ, O’Carroll DC. A new, fluorescence-based method for visualizing the pseudopupil and assessing optical acuity in the dark compound eyes of honeybees and other insects. Sci Rep 2021; 11:21267. [PMID: 34711871 PMCID: PMC8553845 DOI: 10.1038/s41598-021-00407-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Accepted: 10/11/2021] [Indexed: 11/24/2022] Open
Abstract
Recent interest in applying novel imaging techniques to infer optical resolution in compound eyes underscores the difficulty of obtaining direct measures of acuity. A widely used technique exploits the principal pseudopupil, a dark spot on the eye surface representing the ommatidial gaze direction and the number of detector units (ommatidia) viewing that gaze direction. However, dark-pigmented eyes, like those of honeybees, lack a visible pseudopupil. Attempts over almost a century to estimate optical acuity in this species are still debated. Here, we developed a method to visualize a stable, reliable pseudopupil by staining the photoreceptors with fluorescent dyes. We validated this method in several species and found it to outperform the dark pseudopupil for this purpose, even in pale eyes, allowing more precise location of the gaze centre. We then applied this method to estimate the sampling resolution in the frontal part of the eye of the honeybee forager. We found a broad frontal acute zone with interommatidial angles below 2° and a minimum interommatidial angle of 1.3°, a broader, sharper frontal acute zone than previously reported. Our study provides a new method to directly measure the sampling resolution in most compound eyes of living animals.
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Affiliation(s)
- Elisa Rigosi
- grid.4514.40000 0001 0930 2361Department of Biology, Lund University, Sölvegatan 35, 22362 Lund, Sweden
| | - Eric J. Warrant
- grid.4514.40000 0001 0930 2361Department of Biology, Lund University, Sölvegatan 35, 22362 Lund, Sweden
| | - David C. O’Carroll
- grid.4514.40000 0001 0930 2361Department of Biology, Lund University, Sölvegatan 35, 22362 Lund, Sweden
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In search of the spectral composition of an effective light trap for the mushroom pest Lycoriella ingenua (Diptera: Sciaridae). Sci Rep 2021; 11:12770. [PMID: 34140606 PMCID: PMC8211823 DOI: 10.1038/s41598-021-92230-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 04/22/2021] [Indexed: 02/05/2023] Open
Abstract
Certain fungus gnats, like Lycoriella ingenua are notorious pests in agriculture, especially in mushroom production. While larvae cause mainly direct crop damage, adults are vectors of several dangerous fungal pathogens. To promote the development of pesticide-free management methods, such as light trapping, we measured the spectral sensitivity of L. ingenua compound eyes with electroretinography and performed two different behavioural experiments to reveal the wavelength dependence of phototaxis in this species. The spectral sensitivity of the compound eyes is bimodal with peaks at 370 nm (UV) and 526 nm (green). Behavioural experiments showed that attraction to light as a function of wavelength depends on light intensity. In our first experiment, where the minimal photon flux (105-109 photons/cm2/s) needed for eliciting a phototactic response was determined wavelength by wavelength, phototaxis was strongest in the green spectral range (~526 nm). In the other behavioural experiment, where wavelength preference was tested under a higher but constant light intensity (~1013 photons/cm2/s), the highest attraction was elicited by UV wavelengths (398 nm). Our results suggest that both UV and green are important spectral regions for L. ingenua thus we recommend to use both UV (~370-398 nm) and green (~526 nm) for trapping these insects.
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Romell J, Jie VW, Miettinen A, Baird E, Hertz HM. Laboratory phase-contrast nanotomography of unstained Bombus terrestris compound eyes. J Microsc 2021; 283:29-40. [PMID: 33822371 DOI: 10.1111/jmi.13005] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 03/21/2021] [Indexed: 11/30/2022]
Abstract
Imaging the visual systems of bumblebees and other pollinating insects may increase understanding of their dependence on specific habitats and how they will be affected by climate change. Current high-resolution imaging methods are either limited to two dimensions (light- and electron microscopy) or have limited access (synchrotron radiation x-ray tomography). For x-ray imaging, heavy metal stains are often used to increase contrast. Here, we present micron-resolution imaging of compound eyes of buff-tailed bumblebees (Bombus terrestris) using a table-top x-ray nanotomography (nano-CT) system. By propagation-based phase-contrast imaging, the use of stains was avoided and the microanatomy could more accurately be reconstructed than in samples stained with phosphotungstic acid or osmium tetroxide. The findings in the nano-CT images of the compound eye were confirmed by comparisons with light- and transmission electron microscopy of the same sample and finally, comparisons to synchrotron radiation tomography as well as to a commercial micro-CT system were done.
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Affiliation(s)
- Jenny Romell
- Department of Applied Physics, KTH Royal Institute of Technology, Stockholm, Sweden
| | - Vun Wen Jie
- Department of Zoology, Stockholm University, Stockholm, Sweden
| | - Arttu Miettinen
- Institute for Biomedical Engineering, Zurich University and ETH Zurich, Zurich, Switzerland.,Swiss Light Source, Paul Scherrer Institute, Villigen, Switzerland.,Arttu Miettinen, Department of Physics, University of Jyvaskyla, Jyvaskyla, Finland
| | - Emily Baird
- Department of Zoology, Stockholm University, Stockholm, Sweden
| | - Hans M Hertz
- Department of Applied Physics, KTH Royal Institute of Technology, Stockholm, Sweden
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Hu Y, Limaye A, Lu J. Three-dimensional segmentation of computed tomography data using Drishti Paint: new tools and developments. ROYAL SOCIETY OPEN SCIENCE 2020; 7:201033. [PMID: 33489265 PMCID: PMC7813226 DOI: 10.1098/rsos.201033] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 11/24/2020] [Indexed: 05/14/2023]
Abstract
Computed tomography (CT) has become very widely used in scientific and medical research and industry for its non-destructive and high-resolution means of detecting internal structure. Three-dimensional segmentation of computed tomography data sheds light on internal features of target objects. Three-dimensional segmentation of CT data is supported by various well-established software programs, but the powerful functionalities and capabilities of open-source software have not been fully revealed. Here, we present a new release of the open-source volume exploration, rendering and three-dimensional segmentation software, Drishti v. 2.7. We introduce a new tool for thresholding volume data (i.e. gradient thresholding) and a protocol for performing three-dimensional segmentation using the 3D Freeform Painter tool. These new tools and workflow enable more accurate and precise digital reconstruction, three-dimensional modelling and three-dimensional printing results. We use scan data of a fossil fish as a case study, but our procedure is widely applicable in biological, medical and industrial research.
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Affiliation(s)
- Yuzhi Hu
- Department of Applied Mathematics, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia
- Research School of Earth Sciences, Australian National University, Canberra, ACT 2601, Australia
| | - Ajay Limaye
- National Computational Infrastructure, Building 143, Corner of Ward Road and Garran Road, Ward Rd, Canberra, ACT 2601, Australia
| | - Jing Lu
- Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing 100044, People's Republic of China
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Comin CH, Taylor GJ, Costa LDF. Quantifying the regularity of a 3D set of points on the surface of an ellipsoidal object. Pattern Recognit Lett 2020. [DOI: 10.1016/j.patrec.2020.02.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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10
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Taylor GJ, Hall SA, Gren JA, Baird E. Exploring the visual world of fossilized and modern fungus gnat eyes (Diptera: Keroplatidae) with X-ray microtomography. J R Soc Interface 2020; 17:20190750. [PMID: 32019468 PMCID: PMC7061697 DOI: 10.1098/rsif.2019.0750] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Animal eyes typically possess specialized regions for guiding different behavioural tasks within their specific visual habitat. These specializations, and evolutionary changes to them, can be crucial for understanding an animal's ecology. Here, we explore how the visual systems of some of the smallest flying insects, fungus gnats, have adapted to different types of forest habitat over time (approx. 30 Myr to today). Unravelling how behavioural, environmental and phylogenetic factors influence the evolution of visual specializations is difficult, however, because standard quantitative techniques often require fresh tissue and/or provide data in eye-centric coordinates that prevent reliable comparisons between species with different eye morphologies. Here, we quantify the visual world of three gnats from different time periods and habitats using X-ray microtomography to create high-resolution three-dimensional models of the compound eyes of specimens in different preservation states—fossilized in amber, dried or stored in ethanol. We present a method for analysing the geometric details of individual corneal facets and for estimating and comparing the sensitivity, spatial resolution and field of view of species across geographical space and evolutionary time. Our results indicate that, despite their miniature size, fungus gnats do have variations in visual properties across their eyes. We also find some indication that these visual specializations vary across species and may represent adaptations to their different forest habitats. Overall, the findings demonstrate how such investigations can be used to study the evolution of visual specializations—and sensory ecology in general—across a range of insect taxa from different geographical locations and across time.
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Affiliation(s)
| | - Stephen A Hall
- Division of Solid Mechanics, Lund University, Lund, Sweden
| | - Johan A Gren
- Department of Geology, Lund University, Lund, Sweden
| | - Emily Baird
- Department of Biology, Lund University, Lund, Sweden.,Department of Zoology, Stockholm University, Stockholm, Sweden
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