An ancestral luciferase in the Malpighi tubules of a non-bioluminescent beetle!

Abstract

The evolutionary origin of beetle bioluminescence is enigmatic. Previously, weak luciferase activity was found in the non-bioluminescent larvae of Tenebrio molitor (Coleoptera: Tenebrionidae), but the detailed tissular origin and identity of the luciferase-like enzyme remained unknown. Using a closely related giant mealworm, Zophobas morio, here we show that the luciferase-like enzyme is located in the Malpighi tubules. cDNA cloning of this luciferase like enzyme, showed that it is a short AMP-ligase with weak luciferase activity which diverged long ago from beetle luciferases. The results indicate that the potential for bioluminescence in AMP-ligases is very ancient and provide a first reasonable protoluciferase model to investigate the origin and evolution of beetle luciferases.

First transcriptional survey of the Malpighian tubules of giant mealworm, Zophobas morio (Coleoptera: Tenebrionidae)

“…3000 clones of Z. morio Malpighian tubule cDNA library yielded two copies for a luciferase-like enzyme, which was further characterized (Viviani et al, 2009). In this transcriptional survey of the same cDNA library, we did not find other ESTs similar to genes codings for luciferase-like enzymes.…”

“…A cDNA library was previously constructed in the λ UNI-ZAP II vector (STRATA-GENE, LaJolla, CA) using mRNA isolated from the Malpighian tubules of Z. morio (Viviani et al, 2009). The original library had a titer of 2 x 10 6 PFU.…”

“…More recently, our group found and cloned one of these luciferase-like enzymes from the Malpighian tubules in Z. morio larvae (Coleoptera: Tenebrionidae). This luciferase-like enzyme is a Co-A ligase which displays weak luminescence activity in the presence of adenosine triphosphate (ATP) and firefly D-luciferin, a xenobiotic for this non-biouminescent organism (Viviani et al, 2009). Although the Malpighian tubules of this Coleoptera species are not bioluminescent, the presence of ATP-dependent luciferaselike enzymes is noteworthy, because the very distant dipteran relatives Arachnocampa spp display ATP-dependent bioluminescence, arising from lanterns consisting of specialized extensions of the Malpighian tubules (Gatenby, 1960;Viviani et al, 2002).…”

“…Thus, with the aim to better understand the molecular physiology of Malpighian tubules and the function of luciferase-like enzymes in these organs, we carried out the first transcriptional analysis using the previously constructed cDNA library from Malpighian tubules of the giant mealworm, Z. morio (Viviani et al, 2009). …”

Comparative physiology of Malpighian tubules: form and function

“…65,66 The Malpighi tubules of the giant mealworm Zophobas morio (Coleoptera, Tenebrionidae) show a short antimicrobial peptides (AMP)-ligase with weak luciferase activity that diverged long ago from beetle luciferases. 67 These protoluciferases have an evolutionary importance in the investigation of bioluminescence origin in beetles.…”