Biophosphorescence in fluorescent millipedes (Diplopoda: Xystodesmidae) and its relationships with bioluminescence

Author(s)

Viviani, Vadim R.

• Document type: Journal article
• Source: SCIENTIFIC REPORTS; v. 13, n. 1, p. 10-pg., 2023-12-13.

Abstract

Three types of luminescence have been reported in living organisms: bioluminescence (BL), ultraweak chemiluminescence and biofluorescence (FL). In millipedes, both BL and FL have been reported in Motyxia sequoiae and related Xystodesmidae species. Noteworthy, when walking at night with a UV lantern at the Biological Station of Highlands, I found three blue-fluorescent millipedes (Deltotaria brimleii, Deltotoria sp and Euryus orestes) that also displayed phosphorescence after turning off the UV source. The phosphorescence of the cuticle was in the green region (lambda(max) = 525 nm). The phosphorescence remained associated with cuticle and pellets, but frozen fluorescent supernatants, also displayed phosphorescence. The fluorescent compounds extracted from the cuticles in water and methanol and separated by TLC, displayed fluorescence spectra similar to that of 6-pteridine carboxylic acid. In contrast to Motyxia sequoiae cuticle extracts, no bioluminescence was found in Deltatoria and Euryus extracts in the presence of MgATP, but weak green chemiluminescence was detected with H2O2 and superoxide. The spectral overlapping of phosphorescence of these millipedes with the bioluminescence of Motyxia (similar to 507 nm) and the intimate association of both types of luminescence with the cuticles, raises the possibility that bioluminescence in Motyxia may arise from chemiluminescence reactions preferentially generating triplet excited states instead of singlet states. (AU)

• FAPESP's process: 10/05426-8 - Arthropod bioluminescence: biological diversity in Brazilian biomes, biochemical origin, structural/functional evolution of luciferases, molecular differentiation of lanterns, biotechnological, environmental and educational applications
• Grantee: Vadim Viviani
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 22/04800-0 - Development of bioluminescent reagents for immunoassays, environmental analyisis and bioimaging
• Grantee: Vadim Viviani
• Support Opportunities: Regular Research Grants