Opsin diversity and evolution in the Elateroidea superfamily: Insights from transcriptome data.

Vision plays a vital biological role in organisms, which depends on the visual pigment molecules (opsin plus chromophore). The expansion or reduction of spectral channels in the organisms is determined by distinct opsin classes and copy numbers resulting from duplication or loss. Within Coleoptera, the superfamily Elateroidea exhibits a great diversity of morphological and physiological characteristics, such as bioluminescence, making this group an important model for opsin studies. While molecular and physiological studies have been conducted in Lampyridae and Elateridae, other families remain unexplored. Here, we reused transcriptome datasets from Elateroidea species, including members of Elateridae, Lampyridae, Phengodidae, Rhagophthalmidae, Cantharidae, and Lycidae, to detect the diversity of putative opsin genes in this superfamily. In addition, we tested the signature of sites under positive selection in both ultraviolet (UV)- and long-wavelength (LW)-opsin classes. Although the visual system in Elateroidea is considered simple, we observed events of duplication in LW- and UV-opsin, as well as the absence of UV-opsin in distinct families, such as larval Phengodidae individuals. We detected different copies of LW-opsins that were highly expressed in the eyes of distinct tribes of fireflies, indicating the possible selection of each copy during the evolution of the sexual mating to avoid spectrum overlapping. In Elateridae, we found that the bioluminescent species had a distinct LW-opsin copy compared with the non-bioluminescent species, suggesting events of duplication and loss. The signature of positive selection showed only one residue associated with the chromophore binding site in the Elateroidea, which may produce a bathochromic shift in the wavelength absorption spectra in this family. Overall, this study brings important content and fills gaps regarding opsin evolution in Elateroidea.

Exploring Phylogenetic Relationships and Divergence Times of Bioluminescent Species Using Genomic and Transcriptomic Data.

Next-generation sequencing (NGS) has dominated the scene of genomics and evolutionary biology as a great amount of genomic data have been accumulated for a diverse set of species. At the same time, phylogenetic approaches and programs are in development to allow better use of such large-size datasets. Phylogenomics appears as a promising field to accommodate and explore all the information of NGS data in phylogenetic methods, being an important approach to investigate the evolution of bioluminescence in different organisms. To guarantee accurate results in phylogenomic studies, it is mandatory to correctly identify orthologous genes in phylogenetic reconstruction. Here, we show a simplified step-by-step framework to perform phylogenetic analysis along with divergence time estimation, beginning with an orthologous search. As empirical data, we exemplify transcriptome sequences of six species of the Elateroidea superfamily (Coleoptera). We introduce several bioinformatics tools for handling genomic data, especially those available in the software OrthoFinder, IQTREE, BEAST2, and TreePL.

A new genus of Phengodidae (Coleoptera) from the Neotropical Region

Cleicosta, a new genus of Phengodidae containing two new species, C. equatoreana sp. nov., and C. monaguense sp. nov., are described. Additionally, a new combination for Cenophengus breviplumatusWittmer, 1976 is included. Cleicosta gen. nov., is the thirty-eighth genus assigned to the beetle family Phengodidae in the new world and is also the most morphologically similar to Cenophengus LeConte, 1881. Both genera exhibit clearly separated tentorial pits, vertical frons and simple tarsomeres. In Cleicosta gen. nov., however, the antennal rami are 1.5 times longer than the corresponding antennomere, the pronotum is subquadrate and the elytra are short, reaching the first or second abdominal segment. In addition, it presents an aedeagus with lateral lobes slender, parallel exteriorly, narrowed medially to toothless apex.

A new suspected paedomorphic genus of net-winged beetles from the Atlantic Rainforest (Coleoptera, Elateroidea, Lycidae)

Lycidae are among the better studied groups in the superfamily Elateroidea, however despite the progress in the taxonomic understanding of the Neotropical fauna, much still remains unknown and undescribed in the region. The description of the new genus Xenolycus gen. nov., from Serra dos Órgãos, a subrange of the Serra do Mar mountain range, in the Atlantic Rainforest in Rio de Janeiro State, Brazil, contributes to the knowledge of the Neotropical Lycidae fauna. The new genus can be distinguished from all other known Calopterini and Neotropical Lycidae by the combination of a pronotum with a wide, deep and strongly visible longitudinal cell in the disc area, the filiform antennae, the dehiscent elytra with reticulation strongly reduced and bearing only two weakly developed elytral costae and the mouthparts partially reduced, with rudimentary, barely visible mandibles. The type species, Xenolycus costae sp. nov., is illustrated and diagnostic characters and a discussion on the tribal placement of the new genus are provided.

A new suspected paedomorphic genus of net-winged beetles from the Atlantic Rainforest (Coleoptera, Elateroidea, Lycidae)

Lycidae are among the better studied groups in the superfamily Elateroidea, however despite the progress in the taxonomic understanding of the Neotropical fauna, much still remains unknown and undescribed in the region. The description of the new genus Xenolycus gen. nov., from Serra dos Órgãos, a subrange of the Serra do Mar mountain range, in the Atlantic Rainforest in Rio de Janeiro State, Brazil, contributes to the knowledge of the Neotropical Lycidae fauna. The new genus can be distinguished from all other known Calopterini and Neotropical Lycidae by the combination of a pronotum with a wide, deep and strongly visible longitudinal cell in the disc area, the filiform antennae, the dehiscent elytra with reticulation strongly reduced and bearing only two weakly developed elytral costae and the mouthparts partially reduced, with rudimentary, barely visible mandibles. The type species, Xenolycus costae sp. nov., is illustrated and diagnostic characters and a discussion on the tribal placement of the new genus are provided.(AU)

A new genus of Phengodidae (Coleoptera) from the Neotropical Region

Cleicosta, a new genus of Phengodidae containing two new species, C. equatoreana sp. nov., and C. monaguense sp. nov., are described. Additionally, a new combination for Cenophengus breviplumatusWittmer, 1976 is included. Cleicosta gen. nov., is the thirty-eighth genus assigned to the beetle family Phengodidae in the new world and is also the most morphologically similar to Cenophengus LeConte, 1881. Both genera exhibit clearly separated tentorial pits, vertical frons and simple tarsomeres. In Cleicosta gen. nov., however, the antennal rami are 1.5 times longer than the corresponding antennomere, the pronotum is subquadrate and the elytra are short, reaching the first or second abdominal segment. In addition, it presents an aedeagus with lateral lobes slender, parallel exteriorly, narrowed medially to toothless apex.(AU)

A new genus of Phengodidae (Coleoptera) from the Neotropical Region

Abstract Cleicosta, a new genus of Phengodidae containing two new species, C. equatoreana sp. nov., and C. monaguense sp. nov., are described. Additionally, a new combination for Cenophengus breviplumatusWittmer, 1976 is included. Cleicosta gen. nov., is the thirty-eighth genus assigned to the beetle family Phengodidae in the new world and is also the most morphologically similar to Cenophengus LeConte, 1881. Both genera exhibit clearly separated tentorial pits, vertical frons and simple tarsomeres. In Cleicosta gen. nov., however, the antennal rami are 1.5 times longer than the corresponding antennomere, the pronotum is subquadrate and the elytra are short, reaching the first or second abdominal segment. In addition, it presents an aedeagus with lateral lobes slender, parallel exteriorly, narrowed medially to toothless apex.

A new suspected paedomorphic genus of net-winged beetles from the Atlantic Rainforest (Coleoptera, Elateroidea, Lycidae)

Abstract Lycidae are among the better studied groups in the superfamily Elateroidea, however despite the progress in the taxonomic understanding of the Neotropical fauna, much still remains unknown and undescribed in the region. The description of the new genus Xenolycus gen. nov., from Serra dos Órgãos, a subrange of the Serra do Mar mountain range, in the Atlantic Rainforest in Rio de Janeiro State, Brazil, contributes to the knowledge of the Neotropical Lycidae fauna. The new genus can be distinguished from all other known Calopterini and Neotropical Lycidae by the combination of a pronotum with a wide, deep and strongly visible longitudinal cell in the disc area, the filiform antennae, the dehiscent elytra with reticulation strongly reduced and bearing only two weakly developed elytral costae and the mouthparts partially reduced, with rudimentary, barely visible mandibles. The type species, Xenolycus costae sp. nov., is illustrated and diagnostic characters and a discussion on the tribal placement of the new genus are provided.

Comparison of the thermostability of recombinant luciferases from Brazilian bioluminescent beetles: Relationship with kinetics and bioluminescence colours.

Firefly luciferases have been used extensively as bioanalytical reagents and their cDNAs as reporter genes for biosensors and bioimaging, but they are in general unstable at temperatures above 30°C. In the past few years, efforts have been made to stabilize some firefly luciferases for better application as analytical reagents. Novel luciferases from different beetle families, displaying distinct bioluminescence colours and kinetics, may offer desirable alternatives to extend the range of applications. In the past years, our group has cloned the largest variety of luciferases from the three main families of bioluminescent beetles (Elateridae: P. termitilluminans, F. bruchi, P. angustus; Phengodidae: P. hirtus, P. vivianii; and Lampyridae: A. vivianii, C. distinctus and Macrolampis sp2) occurring in Brazilian biomes. We compared the thermostability of these recombinant luciferases and investigated their relationships with bioluminescence spectra and kinetics. The most thermostable luciferases were those of Pyrearinus termitilluminans larval click beetle (534 nm), Amydetes vivianii firefly (539 nm) and Phrixotrix vivianii railroad worm (546 nm), which are the most blue-shifted examples in each family, confirming the trend that the most blue-shifted emitting luciferases are also the most thermostable. Comparatively, commercial P. pyralis firefly luciferase was less thermostable than P. termitilluminans click beetle and A. vivianii firefly luciferases. The higher thermostability in these luciferases could be related to higher degree of hydrophobic packing and disulfide bond content (for firefly luciferases).

Survey of Bioluminescent Coleoptera in the Atlantic Rain Forest of Serra da Paranapiacaba in São Paulo State (Brazil) / Levantamento de Coleópteros bioluminescentes na Mata Atlântica da Serra da Paranapiacaba

Brazil is the country with the largest number of bioluminescent beetle species in the world. However, estimates suggest that this number could much be higher, since many species remain to be discovered. In this work we made a survey of the species of bioluminescent beetles in Serra de Paranapiacaba - the largest remnant of Atlantic Forest in São Paulo State. The survey was done at Intervales State Park, Carlos Botelho State Park and municipality of Tapiraí and the following species were collected: Aspisoma lineatum, Aspisoma physonotum, Aspisoma fenestrata, Cratomorphus besckey, Cratomorphus distinctus, Photinus penai, Photinus sp1, Photinus sp9, Ethra aff. malledicta or axilaris, Ethra aff. adicta , Lucidotini incertae sedis, Cladodes flabellicornis, Cladodes demoulini, Amydetes lucernuta, Bicellonycha sp8, Bicellonycha ornaticollis, Pyrogaster lunifer, Pyrogaster moestus, Pyrogaster sp2, Pyrogaster sp5, Pyrogaster sp6, Photuris lugubris, Photuris sp1, Photuris sp7, Stenophrixotrix sp1, Brasilocerus sp1, Pseudophengodes sp1, Hapsodrilus pyrotis, Hypsiophtalmus sp1, Ptesimopsia luculenta, Pyroptesis cincticollis, Pyrearinus brevicolis, Pyrearinus candelarius, Pyrearinus micatus, Pyrophorus divergens. Our data show that Serra de Paranapiacaba is the second richest area in São Paulo state, especially in elaterids, with unique species typical of this area and species common to other investigated sites such as the Biological Station of Boracéia (in Salesópolis county) and the urbanized areas in the between Campinas - Sorocaba- São Paulo, originally covered to the Atlantic Rainforest.

O Brasil é o país que possui o maior número de espécies de coleópteros bioluminescentes no mundo. Entretanto, estimativas sugerem que este número possa ser bem maior, dado que muitas espécies ainda não foram descritas. Neste trabalho foi realizado um levantamento das espécies de coleópteros bioluminescentes em três localidades na Serra da Paranapiacaba - a maior área remanescente contígua de Mata Atlântica no país, com associação ao respectivo habitat. No Parque Estadual Intervales, Parque Estadual Carlos Botelho e Tapiraí foram coletadas as seguintes espécies: (Lampyidae) Aspisoma lineatum, Aspisoma physonotum, Aspisoma fenestrata, Cratomorphus besckey, Cratomorphus distinctus, Photinus penai, Photinus sp1, Photinus sp9, Ethra aff. malledicta ou axilaris, Ethra aff. adicta, Lucidotini incertae sedis, Cladodes flabellicornis, Cladodes demoulini, Amydetes sp1, Bicellonycha sp8, Bicellonycha ornaticollis, Pyrogaster lunifer, Pyrogaster moestus, Pyrogaster sp2, Pyrogaster sp5, Pyrogaster sp6, Photuris lugubris, Photuris sp1, Photuris sp7; (Phengodidae) Stenophrixotrix sp1, Brasilocerus sp2, Pseudophengodes sp1; (Elateridae) Hapsodrilus pyrotis, Hypsiophtalmus sp1, Ptesimopsia luculenta, Pyroptesis cincticollis, Pyrearinus brevicolis, Pyrearinus candelarius, Pyrearinus micatus, Pyrophorus divergens. Estes dados mostram que esta constitui a segunda área mais rica em espécies luminescentes do Estado de São Paulo, depois da Est. Biológica de Boracéia, especialmente em elaterídeos, com espécies únicas características destas localidades e espécies comuns è outras áreas investigadas, como as da Estação Biológica de Boracéia (Salesópolis, SP) e áreas urbanizadas no triângulo Campinas - Sorocaba - São Paulo, originalmente cobertas por Mata Atlântica.

Nine genera of Eucnemidae (Coleoptera) new to Peru, with a key to Peruvian genera.

Thirteen genera of Eucnemidae containing forty species were collected from the Iquitos region in Peru. Nine of the genera are new to the country: Rhagomicrus Fleutiaux, 1902, Adelorhagus Horn, 1890, Adelothyreus Chevrolat, 1867, Microrhagus Dejean, 1833, Dyscharachthis Blackburn, 1900, Heterotaxis Bonvouloir, 1871, Spinifornax Fleutiaux, 1926, Serrifornax Fleutiaux, 1926 and Maelodrus Fleutiaux, 1928. The previous eucnemid record from Peru contained eleven species in ten genera. Only one of the forty species caught, Entomophthalmusamericanus Bonvouloir, was previously known and described from the country. Dyscharachthis, Maelodrus and Adelorhagus are recorded from South America for the first time. Many of the collected species seem to favor white-sand forest as their habitat. Possible reasons for this are discussed. A list of eucnemids from Peru is included, containing taxa already recorded from the country and also taxa that are likely to occur there. A key to the Peruvian genera is included.