Hirobumi Suzuki

By Hirobumi Suzuki, May-Maw-Thet, Yoko Hatta-Ohashi, Ryutaro Akiyoshi and Taro Hayashi

Bioluminescence imaging by microscopy is performed using an ultra-low-light imaging camera. Although imaging devices such as sensor and camera have been greatly improved over time, such improvements have not been attained commercially which are available for microscopes now. We previously optimized the optical system of a microscope for bioluminescence imaging using a short-focal-length imaging lens and evaluated this system with a conventional color charge-coupled device camera. Here, we describe the concept of bioluminescence microscope design using a short-focal-length imaging lens and some representative applications, including intracellular calcium imaging, imaging of clock gene promoter assays, and three-dimensional reconstruction of Drosophila larva. This system facilitates the acquisition of bioluminescence images of single live cells using luciferase, which is similar to fluorescence microscopy using a fluorescent protein.

Part of the book: Luminescence

By Tadasu Sano, Yukimasa Kobayashi, Ikuko Sakai, Katsunori Ogoh and Hirobumi Suzuki

Some species of springtail (Collembola) are luminous, but it is not known whether light emitted by springtail is due to self-luminescence, feeding on luminous fungi, or accidental infection by luminous bacteria. To address this question, we characterized the luminescence of a luminous springtail, Lobella sp. (family Neanuridae) discovered in Tokyo, Japan. The emitted light was yellowish-green (540 nm) and was found to originate from tubercles on the thorax (segments II and III) and abdomen (segments I–VI) using a low-light imaging system. The luminescence persisted for several seconds but showed occasional oscillations in a laboratory environment. We also observed fat bodies containing eosin-positive granules under the integument of the tubercles in the tergum by hematoxylin and eosin (HE) staining that were not present in a nonluminous springtail (Vitronura sp.). The fat bodies in Lobella sp. are presumably photocytes analogous to the firefly lantern, and the eosin-positive granules are the likely source of bioluminescence, which implies that springtails are self-luminescent.

Part of the book: Bioluminescence

By Taro Hayashi, Katsunori Ogoh and Hirobumi Suzuki

Cyclic adenosine monophosphate (cAMP), which is derived from adenosine triphosphate through adenylyl cyclase A (acaA), acts as an intracellular secondary messenger and an extracellular chemotactic substance in important biological processes. In the social amoebae Dictyostelium discoideum, cAMP mediates cell aggregation, development, and differentiation to spore and stalk cells during fruiting body formation. The acaA gene is transcribed under the control of three different alternative promoters. This study aimed to develop a promoter assay for acaA in D. discoideum using bioluminescence microscopy. Here, we inserted green- and red-emitting luciferase genes into downstream of promoter regions 1 and 3, respectively. Promoter activities were visualized by bioluminescence microscopy. We confirmed the differential expression of acaA under the control of promoters 1 and 3 at the different stages of D. discoideum development. We also demonstrated the application of dual-color bioluminescence imaging in the development of an imaging promoter assay.

Part of the book: Bioluminescence