ABSTRACT
Among bioluminescent beetles of the Elateroidea superfamily, Phengodidae is the third largest family, with 244 bioluminescent species distributed only in the Americas, but is still the least studied from the phylogenetic and evolutionary points of view. The railroad worm Phrixothrix hirtus is an essential biological model and symbolic species due to its bicolor bioluminescence, being the only organism that produces true red light among bioluminescent terrestrial species. Here, we performed partial genome assembly of P. hirtus, combining short and long reads generated with Illumina sequencing, providing the first source of genomic information and a framework for comparative analyses of the bioluminescent system in Elateroidea. This is the largest genome described in the Elateroidea superfamily, with an estimated size of â¼3.4 Gb, displaying 32 % GC content, and 67 % transposable elements. Comparative genomic analyses showed a positive selection of genes and gene family expansion events of growth and morphogenesis gene products, which could be associated with the atypical anatomical development and morphogenesis found in paedomorphic females and underdeveloped males. We also observed gene family expansion among distinct odorant-binding receptors, which could be associated with the pheromone communication system typical of these beetles, and retrotransposable elements. Common genes putatively regulating bioluminescence production and control, including two luciferase genes corresponding to lateral lanterns green-emitting and head lanterns red-emitting luciferases with 7 exons and 6 introns, and genes potentially involved in luciferin biosynthesis were found, indicating that there are no clear differences about the presence or absence of gene families associated with bioluminescence in Elateroidea.
Subject(s)
Coleoptera , Railroads , Animals , Female , Phylogeny , DNA Transposable Elements , Odorants , Coleoptera/genetics , Coleoptera/metabolism , Luciferases/metabolism , Morphogenesis , PheromonesABSTRACT
Bioluminescence is widely used in biosensors. Firefly luciferase-based bioluminescent sensors are among the most popular ones. Firefly luciferases are pH-sensitive, displaying a large red shift at acidic pH, a property that has been considered undesirable for most applications. Currently, biosensors that can detect intracellular pH are in demand, and some fluorescent biosensors are available. However, pH sensors using bioluminescence have not been used yet. Thus, we decided to harness a firefly luciferase to measure the intracellular pH in mammalian cells. For this purpose, we engineered the luciferase derived from Macrolampis sp2 firefly to localize it on the cytosol or nucleus, in order to observe pH variation in these compartments during biological activities. We first calibrated the emission ratios (R = Igreen/Ired) at different pH values. As expected, we observed a red shift of light emission under acidic conditions when the cells were subjected to different pH conditions in the presence of the K+/H+ ionophore, nigericin. Based on these results, we concluded that this firefly luciferase can be used as a diagnostic tool for measuring the intracellular pH variation in pathogenic cells or in cells during apoptosis. This is the first example of real time-monitoring of pH change using color tuning luciferase.
Subject(s)
Biosensing Techniques , Luciferases, Firefly/metabolism , Luminescent Measurements , Organelles/metabolism , Animals , COS Cells , Chlorocebus aethiops , Fireflies , Hydrogen-Ion Concentration , Organelles/chemistryABSTRACT
Brazil hosts the richest biodiversity of bioluminescent beetles in the world. Several species are found in the Atlantic rain forest, one of the richest and most threatened tropical forests in the world. We have catalogued the biodiversity of bioluminescent species mainly of Elateroidea superfamily occurring in one of the last largest and most preserved remnants of Atlantic rain forest, located at the Biological Station of Boracéia of São Paulo University (Salesopolis, SP, Brazil). This site accounted with the largest diversity ever found for a single place in São Paulo State, with 39 species: Lampyridae (30), Phengodidae (5), Elateridae (3) and Staphylinidae (1). This fauna has unique species that were not found in any other places of Atlantic forest in São Paulo state, especially fireflies from the Lampyrinae tribes (Cratomorphini, Lamprocerini, Lucidotini), the subfamilies Amydetinae and Photurinae, and the phengodids Pseudophengodes and Brasilocerus sp.2. Most species are found in dense Ombrophyl forest or at their border, and a few ones are found dwelling in the few open fields around the forest. There is a predominance of glowing patterns in the green region among forest inhabiting species when compared with open field fireflies.
O Brasil tem a maior biodiversidade de coleópteros bioluminescentes do mundo. Muitas destas espécies são encontradas na Mata Atlantica, um dos mais ricos e ameaçados ecossitemas. Catalogamos a biodiversidade de espécies bioluminescentes da superfamília Elateroidea em um dos maiores e mais preservados remanescentes de Mata Atlântica da Serra do Mar, localizado na Estação Biológica de Boraceia (E.B.B.) em Salesopolis, SP, reserva administrada pelo Museu de Zoologia da Universidade de São Paulo. Este local contou com a maior biodiversidade de espécies bioluminescentes já encontrada num único local dentro do estado, com 39 espécies: Lampyridae (30), Phengodidae (5), Elateridae (3) e Staphylinidae (1). Esta fauna tem espécies únicas não encontradas em nenhum outro lugar investigado de Mata Atlântica no estado de São Paulo, especialmente das tribos de Lampyrinae (Cratomorphini, Lamprocerini, Lucidotini), as subfamílias Amydetinae e Photurinae, e os fengodídeos Pseudophengodes e Brasilocerus sp.2. A maioria das espécies ocorre em floresta ombrófila densa, e poucas ocorrem em campos abertos. Existe uma predominância de espécies com padrões de brilho contínuo na região do verde no interior da mata quando comparadas a espécies de vagalumes de campo aberto.
ABSTRACT
O Brasil abriga a maior biodiversidade de besouros bioluminescentes do mundo. Apesar disto, levantamentos faunísticos regionais e estudos sobre o efeito da urbanização na biodiversidade de vaga-lumes são inexistentes. Este tipo de estudo pode ser especialmente importante para selecionar novos bioindicadores de ambientes noturnos. A biodiversidade de espécies bioluminescentes de Elateroidea em três grandes áreas urbanas no Estado de São Paulo: os municípios de Campinas, Sorocaba-Votorantim e Rio Claro-Limeira foi catalogada. Em Campinas, a ocorrência de espécies tem sido monitorada durante os últimos 20 anos. Foi registrada a ocorrência de 26 espécies em Campinas, 21 em Sorocaba e 19 em Rio Claro, sendo estas encontradas principalmente em áreas de Mata Atlântica, crescimentos secundários, brejos e campos. Apesar de vaga-lumes lampirídeos serem encontrados em todos os habitats, elaterídeos e fengodídeos ocorreram encontrados preferencialmente em áreas florestadas. A expansão urbana, em especial a iluminação artificial tem impacto evidente na biodiversidade deste grupo de insetos. Os lampirídeos Aspisoma lineatum Gyllendal, 1817 (Lampyrinae: Cratomorphini) e Bicellonychia lividipennis Motschulsky, 1854 (Photurinae) são as espécies mais frequentes em areas urbanizadas, ao passo que várias outras espécies de lampirídeos, elaterídeos e fengodídeos são as mais incomuns nestas áreas. Estes estudos oferecem subsídios para o uso deste grupo de vaga-lumes como potenciais bioindicadores noturnos.
Brazil hosts the richest biodiversity of bioluminescent beetles in the world. However, no surveys on the regional biodiversity have been made. Furthermore, studies on the effect of urbanization on bioluminescent beetle's biodiversity are still missing. Such kind of studies could be especially helpful to select new night environment bioindicators. Bioluminescent species of the Elateroidea superfamily occurring in three large and expanding urban areas in São Paulo State: Campinas, Sorocaba-Votorantim and Rio Claro-Limeira municipalities, were catalogued. In Campinas, the occurrence of bioluminescent beetles in different sites has been monitored during the past 20 years. There were 26 species in Campinas, 21 in Sorocaba-Votorantim and 19 in Rio Claro-Limeira, occurring mainly in conserved remnants of Atlantic Rain-forest, secondary growths, marshes and open fields. Whereas fireflies (Lampyridae) are found in almost all habitats, click beetles (Elateridae) and railroadworms (Phengodidae) occur predominantly in woody environments. Urban sprawl has an evident impact on the biodiversity of this selected group of beetles, and special attention should be given to the effect of artificial night lighting in the occurrence of these beetles. The lampyrids Aspisoma lineatum Gyllenhal, 1817 (Lampyrinae: Cratomorphini) and Bicellonychia lividipennis Motschulsky 1854 (Photurinae) are the most common species in urbanized areas, whereas many other species of lampyrids, elaterids and phengodids are rarely found in such environments. These studies offer insights on the potential use of a selected group of luminescent beetles found in this region as nocturnal environment bioindicators.
