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1.
Mol Phylogenet Evol ; 173: 107522, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35595008

RESUMO

In the framework of neutral theory of molecular evolution, genes specific to the development and function of eyes in subterranean animals living in permanent darkness are expected to evolve by relaxed selection, ultimately becoming pseudogenes. However, definitive empirical evidence for the role of neutral processes in the loss of vision over evolutionary time remains controversial. In previous studies, we characterized an assemblage of independently-evolved water beetle (Dytiscidae) species from a subterranean archipelago in Western Australia, where parallel vision and eye loss have occurred. Using a combination of transcriptomics and exon capture, we present evidence of parallel coding sequence decay, resulting from the accumulation of frameshift mutations and premature stop codons, in eight phototransduction genes (arrestins, opsins, ninaC and transient receptor potential channel genes) in 32 subterranean species in contrast to surface species, where these genes have open reading frames. Our results provide strong evidence to support neutral evolutionary processes as a major contributing factor to the loss of phototransduction genes in subterranean animals, with the ultimate fate being the irreversible loss of a light detection system.


Assuntos
Besouros , Animais , Besouros/genética , Evolução Molecular , Opsinas/genética , Filogenia , Água
2.
Genome ; 64(3): 181-195, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32552081

RESUMO

The subterranean islands hypothesis for calcretes of the Yilgarn region in Western Australia applies to many stygobitic (subterranean-aquatic) species that are "trapped" evolutionarily within isolated aquifers due to their aquatic lifestyles. In contrast, little is known about the distribution of terrestrial-subterranean invertebrates associated with the calcretes. We used subterranean Collembola from the Yilgarn calcretes to test the hypothesis that troglobitic species, those inhabiting the subterranean unsaturated (non-aquatic) zone of calcretes, are also restricted in their distribution and represent reciprocally monophyletic and endemic lineages. We used the barcoding fragment of the mtDNA cytochrome c oxidase subunit 1 (COI) gene from 183 individuals to reconstruct the phylogenetic history of the genus Pseudosinella Schäffer (Collembola, Lepidocyrtidae) from 10 calcretes in the Yilgarn. These calcretes represent less than 5% of the total possible calcretes in this region, yet we show that their diversity for subterranean Collembola comprises a minimum of 25 new species. Regionally, multiple levels of diversity exist in Pseudosinella, indicative of a complex evolutionary history for this genus in the Yilgarn. These species have probably been impacted by climatic oscillations, facilitating their dispersal across the landscape. The results represent a small proportion of the undiscovered diversity in Australia's arid zone.


Assuntos
Artrópodes/classificação , Artrópodes/genética , Animais , Biodiversidade , Carbonato de Cálcio , Complexo IV da Cadeia de Transporte de Elétrons/genética , Variação Genética , Filogenia , Filogeografia , Austrália Ocidental
3.
Mol Phylogenet Evol ; 142: 106643, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31622741

RESUMO

Like other crustacean families, the Parabathynellidae is a poorly studied subterranean and aquatic (stygobiontic) group in Australia, with many regions of available habitat having not yet been surveyed. Here we used a combined approach of molecular species delimitation methods, applied to mitochondrial and nuclear genetic data, to identify putative new species from material obtained from remote subterranean habitats in the Pilbara region of Western Australia. Based on collections from these new localities, we delineated a minimum of eight and up to 24 putative new species using a consensus from a range of molecular delineation methods and additional evidence. When we placed our new putative species into the broader phylogenetic framework of Australian Parabathynellidae, they grouped with two known genera and also within one new and distinct Pilbara-only clade. These new species significantly expand the known diversity of Parabathynellidae in that they represent a 22% increase to the 109 currently recognised species globally. Our investigations showed that sampling at new localities can yield extraordinary levels of new species diversity, with the majority of species showing likely restricted endemic geographical ranges. These findings represent only a small sample from a region comprising less than 2.5% of the Australian continent.


Assuntos
Crustáceos/classificação , Animais , Biodiversidade , Crustáceos/genética , Ecossistema , Filogenia , Austrália Ocidental
4.
Annu Rev Entomol ; 63: 389-406, 2018 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-29058979

RESUMO

The braconid parasitoid wasp subfamily Microgastrinae is perhaps the most species-rich subfamily of animals on Earth. Despite their small size, they are familiar to agriculturalists and field ecologists alike as one of the principal groups of natural enemies of caterpillars feeding on plants. Their abundance and nearly ubiquitous terrestrial distribution, their intricate interactions with host insects, and their historical association with mutualistic polydnaviruses have all contributed to Microgastrinae becoming a key group of organisms for studying parasitism, parasitoid genomics, and mating biology. However, these rich sources of data have not yet led to a robust genus-level classification of the group, and some taxonomic confusion persists as a result. We present the current status of understanding of the general biology, taxonomic history, diversity, geographical patterns, host relationships, and phylogeny of Microgastrinae as a stimulus and foundation for further study. Current progress in elucidating the biology and taxonomy of this important group is rapid and promises a revolution in the classification of these wasps in the near future.


Assuntos
Vespas/genética , Animais , Biodiversidade , Coevolução Biológica , Especificidade de Hospedeiro , Filogenia , Polydnaviridae , Vespas/classificação , Vespas/virologia
5.
Mol Phylogenet Evol ; 126: 153-161, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29678644

RESUMO

Australian cave crickets are members of the subfamily Macropathinae (Orthoptera: Rhaphidophoridae). The subfamily is thought to have originated prior to the tectonic separation of the supercontinent Gondwana based on distributions of extant lineages and molecular phylogenetic evidence, although the Australian fauna have been underrepresented in previous studies. The current study augments existing multigene data (using 12S, 16S, and 28S rRNA genes) to investigate the placement of the Australian representatives within the Macropathinae and to assess divergence dates of select clades. Results suggest that the endemic Tasmanian genus Parvotettix is the sister lineage to the remaining members of the subfamily, an outcome that presents a paraphyletic Australian fauna in contrast to previous studies. All other Australian taxa represented in this study (Micropathus and Novotettix) emerged as a sister group to the New Zealand and South American macropathine lineages. Estimation of phylogenetic divergence ages among the aforementioned clades were calibrated using two methods, in absence of suitable fossil records: (i) tectonic events depicting the fragmentation of Gondwanan landmasses that invoke vicariant scenarios of present day geographic distributions; and (ii) molecular evolutionary rates. Geological calibrations place the median age of the most recent common ancestor of extant macropathines at ∼125 to ∼165 Ma, whereas analyses derived from molecular substitution rates suggest a considerably younger origin of ∼32 Ma. This phylogenetic study represents the most rigorous taxonomic sampling of the Australian cave cricket fauna to date and stresses the influence of lineage representation on biogeographic inference.


Assuntos
Cavernas , Gryllidae/classificação , Filogenia , Animais , Austrália , Teorema de Bayes , Variação Genética , Gryllidae/genética , Nova Zelândia , Fatores de Tempo
6.
Mol Phylogenet Evol ; 109: 302-320, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28126515

RESUMO

The formation and spread of the Australian arid zone during the Neogene was a profoundly transformative event in the biogeographic history of Australia, resulting in extinction or range contraction in lineages adapted to mesic habitats, as well as diversification and range expansion in arid-adapted taxa (most of which evolved from mesic ancestors). However, the geographic origins of the arid zone biota are still relatively poorly understood, especially among highly diverse invertebrate lineages, many of which are themselves poorly documented at the species level. Spiny trapdoor spiders (Idiopidae: Arbanitinae) are one such lineage, having mesic 'on-the-continent' Gondwanan origins, while also having experienced major arid zone radiations in select clades. In this study, we present new orthologous nuclear markers for the phylogenetic inference of mygalomorph spiders, and use them to infer the phylogeny of Australasian Idiopidae with a 12-gene parallel tagged amplicon next-generation sequencing approach. We use these data to test the mode and timing of diversification of arid-adapted idiopid lineages across mainland Australia, and employ a continent-wide sampling of the fauna's phylogenetic and geographic diversity to facilitate ancestral area inference. We further explore the evolution of phenotypic and behavioural characters associated with both arid and mesic environments, and test an 'out of south-western Australia' hypothesis for the origin of arid zone clades. Three lineages of Idiopidae are shown to have diversified in the arid zone during the Miocene, one (genus Euoplos) exclusively in Western Australia. Arid zone Blakistonia likely had their origins in South Australia, whereas in the most widespread genus Aganippe, a more complex scenario is evident, with likely range expansion from southern Western Australia to southern South Australia, from where the bulk of the arid zone fauna then originated. In Aganippe, remarkable adaptations to phragmotic burrow-plugging in transitional arid zone taxa have evolved twice independently in Western Australia, while in Misgolas and Cataxia, burrow door-building behaviours have likely been independently lost at least three times in the eastern Australian mesic zone. We also show that the presence of idiopids in New Zealand (Cantuaria) is likely to be the result of recent dispersal from Australia, rather than ancient continental vicariance. By providing the first comprehensive, continental synopsis of arid zone biogeography in an Australian arachnid lineage, we show that the diversification of arbanitine Idiopidae was intimately associated with climate shifts during the Neogene, resulting in multiple Mio-Pliocene radiations.


Assuntos
Evolução Biológica , Mudança Climática , Aranhas/genética , Animais , Austrália , Ecossistema , Especiação Genética , Nova Zelândia , Filogenia , Austrália do Sul , Aranhas/classificação , Austrália Ocidental
7.
Mol Phylogenet Evol ; 101: 224-241, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27179700

RESUMO

Parasitoid wasps of the subfamily Cheloninae are both species rich and poorly known. Although the taxonomy of Cheloninae appears to be relatively stable, there is no clear understanding of relationships among higher-level taxa. We here applied molecular phylogenetic analyses using three markers (COI, EF1α, 28S) and 37 morphological characters to elucidate the evolution and systematics of these wasps. Analyses were based on 83 specimens representing 13 genera. All genera except Ascogaster, Phanerotoma, and Pseudophanerotoma formed monophyletic groups; Furcidentia (stat. rev.) is raised to generic rank. Neither Chelonus (Chelonus) nor Chelonus (Microchelonus) were recovered as monophyletic, but together formed a monophyletic lineage. The tribes Chelonini and Odontosphaeropygini formed monophyletic groups, but the Phanerotomini sensu Zettel and Pseudophanerotomini were retrieved as either para- or polyphyletic. The genera comprising the former subfamily Adeliinae were confirmed as being nested within the Cheloninae. To estimate the age of the subfamily, we used 16 fossil taxa. Three approaches were compared: fixed-rate dating, node dating, and total-evidence dating, with age estimates differing greatly between the three methods. Shortcomings of each approach in relation to our dataset are discussed, and none of the age estimates is deemed sufficiently reliable. Given that most dating studies use a single method only, in most cases without presenting analyses on the sensitivity to priors, it is likely that numerous age estimates in the literature suffer from a similar lack of robustness. We argue for a more rigorous approach to dating analyses and for a faithful presentation of uncertainties in divergence time estimates. Given the results of the phylogenetic analysis the following taxonomic changes are proposed: Furcidentia Zettel (stat. rev.), previously treated as a subgenus of Pseudophanerotoma Zettel is raised to generic rank; Microchelonus Szépligeti (syn. nov.), variously treated by previous authors, is proposed as a junior synonym of Chelonus Jurine; the following subgenera of Microchelonus - Baculonus Braet & van Achterberg (syn. nov.), Carinichelonus Tobias (syn. nov.) and Scabrichelonus He, Chen & van Achterberg (syn. nov.), are proposed as junior synonyms of Chelonus; a number of new species names are proposed due to homonyms resulting from the above changes and these are listed in the paper.


Assuntos
Vespas/classificação , Animais , Evolução Biológica , DNA/química , DNA/isolamento & purificação , DNA/metabolismo , Proteínas de Ligação a DNA/genética , Fósseis , Masculino , Mitocôndrias/genética , Filogenia , RNA Ribossômico 28S/genética , Análise de Sequência de DNA , Vespas/genética
8.
Mol Phylogenet Evol ; 104: 83-98, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27469380

RESUMO

Groundwater calcrete aquifers of central Western Australia have been shown to contain a high diversity of stygobiont (subterranean aquatic) invertebrates, with each species confined to an individual calcrete and the entire system resembling a 'subterranean archipelago' containing hundreds of isolated calcretes. Here, we utilised alternative sampling techniques above the water table and uncovered a significant fauna of subterranean terrestrial oniscidean isopods from the calcretes. We explored the diversity and evolution of this fauna using molecular analyses based on one mitochondrial gene, Cytochrome C Oxidase Subunit I (COI), two Ribosomal RNA genes (28S and 18S), and one protein coding nuclear gene, Lysyl-tRNA Synthetase (LysRS). The results from 12 calcretes showed the existence of 36 divergent DNA lineages belonging to four oniscidean families (Paraplatyarthridae, Armadillidae, Stenoniscidae and Philosciidae). Using a combination of phylogenetic and species delimitation methods, we hypothesized the occurrence of at least 27 putative new species of subterranean oniscideans, of which 24 taxa appeared to be restricted to an individual calcrete, lending further support to the "subterranean island hypothesis". Three paraplatyarthrid species were present on adjacent calcretes and these exceptions possessed more ommatidia and body pigments compared with the calcrete-restricted taxa, and are likely to represent troglophiles. The occurrence of stenoniscid isopods in the calcretes of central Western Australia, a group previously only known from the marine littoral zone, suggests a link to the marine inundation of the Eucla basin during the Late Eocene. The current oniscidean subterranean fauna consists of groups known to be subtropical, littoral and benthic, reflecting different historical events that have shaped the evolution of the fauna in the calcretes.


Assuntos
Isópodes/classificação , Animais , Biodiversidade , Citocromos c/classificação , Citocromos c/genética , Citocromos c/metabolismo , DNA/química , DNA/isolamento & purificação , DNA/metabolismo , Bases de Dados Genéticas , Água Subterrânea/parasitologia , Isópodes/genética , Lisina-tRNA Ligase/classificação , Lisina-tRNA Ligase/genética , Lisina-tRNA Ligase/metabolismo , Filogenia , RNA Ribossômico 18S/classificação , RNA Ribossômico 18S/genética , RNA Ribossômico 18S/metabolismo , RNA Ribossômico 28S/classificação , RNA Ribossômico 28S/genética , RNA Ribossômico 28S/metabolismo , Alinhamento de Sequência , Análise de Sequência de DNA , Austrália Ocidental
9.
Mol Biol Evol ; 31(3): 636-44, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24336845

RESUMO

Recombination has been proposed as a possible mechanism to explain mitochondrial (mt) gene rearrangements, although the issue of whether mtDNA recombination occurs in animals has been controversial. In this study, we sequenced the entire mt genome of the megaspilid wasp Conostigmus sp., which possessed a highly rearranged mt genome. The sequence of the A+T-rich region contained a number of different types of repeats, similar to those reported previously in the nematode Meloidogyne javanica, in which recombination was discovered. In Conostigmus, we detected the end products of recombination: a range of minicircles. However, using isolated (cloned) fragments of the A+T-rich region, we established that some of these minicircles were found to be polymerase chain reaction (PCR) artifacts. It appears that regions with repeats are prone to PCR template switching or PCR jumping. Nevertheless, there is strong evidence that one minicircle is real, as amplification primers that straddle the putative breakpoint junction produce a single strong amplicon from genomic DNA but not from the cloned A+T-rich region. The results provide support for the direct link between recombination and mt gene rearrangement. Furthermore, we developed a model of recombination which is important for our understanding of mtDNA evolution.


Assuntos
DNA Circular/genética , DNA Mitocondrial/genética , Rearranjo Gênico/genética , Genoma Mitocondrial/genética , Recombinação Genética , Vespas/genética , Animais , Artefatos , Reparo do DNA/genética , Eletroforese em Gel de Ágar , Modelos Genéticos , Dados de Sequência Molecular , Reação em Cadeia da Polimerase
10.
Zootaxa ; 3694: 486-92, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-26312306

RESUMO

The apparently rare chelonine wasp genus Wushenia Zettel was previously known only from a single species Wushenia nana Zettel, collected by Townes at 1150 m from Wushe, Taiwan in 1983. Here we describe a second species, Wushenia australiensis sp. nov. from coastal New South Wales, Australia. This second species extends the known distribution of the genus from the Oriental into the Australasian region, indicating either an extreme disjunct distribution or that Wushenia may also occur on the landmasses inbetween, e.g. the Philippines, Malaysia, Indonesia and/or Papua New Guinea. In addition to a detailed description of the new species, a re-diagnosis of the genus and type species, and a key to species are presented.


Assuntos
Vespas/classificação , Distribuição Animal , Estruturas Animais/anatomia & histologia , Estruturas Animais/crescimento & desenvolvimento , Animais , Austrália , Tamanho Corporal , Feminino , Masculino , Tamanho do Órgão , Vespas/anatomia & histologia , Vespas/crescimento & desenvolvimento
11.
Mol Ecol Resour ; 23(6): 1257-1274, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36999608

RESUMO

Stygofauna are aquatic fauna that have evolved to live underground. The impacts of anthropogenic climate change, extraction and pollution on groundwater pose major threats to groundwater health, prompting the need for efficient and reliable means to detect and monitor stygofaunal communities. Conventional survey techniques for these species rely on morphological identification and can be biased, labour-intensive and often indeterminate to lower taxonomic levels. By contrast, environmental DNA (eDNA)-based methods have the potential to dramatically improve on existing stygofaunal survey methods in a large range of habitats and for all life stages, reducing the need for the destructive manual collection of often critically endangered species or for specialized taxonomic expertise. We compared eDNA and haul-net samples collected in 2020 and 2021 from 19 groundwater bores and a cave on Barrow Island, northwest Western Australia, and assessed how sampling factors influenced the quality of eDNA detection of stygofauna. The two detection methods were complementary; eDNA metabarcoding was able to detect soft-bodied taxa and fish often missed by nets, but only detected seven of the nine stygofaunal crustacean orders identified from haul-net specimens. Our results also indicated that eDNA metabarcoding could detect 54%-100% of stygofauna from shallow-water samples and 82%-90% from sediment samples. However, there was significant variation in stygofaunal diversity between sample years and sampling types. The findings of this study demonstrate that haul-net sampling has a tendency to underestimate stygofaunal diversity and that eDNA metabarcoding of groundwater can substantially improve the efficiency of stygofaunal surveys.


Assuntos
DNA Ambiental , Água Subterrânea , Animais , DNA Ambiental/genética , Biodiversidade , Código de Barras de DNA Taxonômico/métodos , Ecossistema , Monitoramento Ambiental/métodos
12.
Ecol Evol ; 13(10): e10552, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37780085

RESUMO

Recent studies have identified a significant number of endogenous cellulase genes in various arthropods, including isopods, allowing them to process hydrocarbons efficiently as a food source. While this research has provided insight into underlying gene-level processes in cellulose decomposition by arthropods, little is known about the existence and expression of cellulase genes in species from cave environments where carbohydrates are sparse. To investigate whether endogenous cellulase genes are maintained in subterranean species, we sequenced the transcriptomes of two subterranean paraplatyarthrid isopod species from calcrete (carbonate) aquifers of central Western Australia and a related surface isopod species. Seven protein-coding open-reading frames associated with endoglucanase genes were identified in all species. Orthology inference analyses, using a wide range of cellulase sequences from available databases, supported the endogenous origin of the putative endoglucanase genes. Selection analyses revealed that these genes are primarily subject to purifying selection in most of the sites for both surface and subterranean isopod species, indicating that they are likely to encode functional peptides. Furthermore, evolutionary branch models supported the hypothesis of an adaptive shift in selective pressure acting on the subterranean lineages compared with the ancestral lineage and surface species. Branch-site models also revealed a few amino acid sites on the subterranean branches to be under positive selection, suggesting the acquisition of novel adaptations to the subterranean environments. These findings also imply that hydrocarbons exist in subsurface aquifers, albeit at reduced levels, and have been utilized by subterranean isopods as a source of energy for millions of years.

13.
Mol Phylogenet Evol ; 63(3): 904-14, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22450357

RESUMO

The Cotesia flavipes complex of parasitoid wasps (Hymenoptera: Braconidae) are economically important for the biological control of lepidopteran stemboring pests associated with gramineous crops. Some members of the complex successfully parasitize numerous stemborer pest species, however certain geographic populations have demonstrated variation in the range of hosts that they parasitize. In addition, the morphology of the complex is highly conserved and considerable confusion surrounds the identity of species and host-associated biotypes. We generated nucleotide sequence data for two mtDNA genes (COI, 16S) and three anonymous nuclear loci (CfBN, CfCN, CfEN) for the C. flavipes complex. To analyze genetic variation and relationships among populations we used (1) concatenated mtDNA and nDNA data, (2) a nDNA multilocus network approach, and (3) two species tree inference methods, i.e. Bayesian estimation of species trees (BEST) and Bayesian inference of species trees from multilocus data with (*)BEAST. All phylogenetic analyses provide strong support for monophyly of the complex and the presence of at least four species, C. chilonis (from China and Japan), C. sesamiae (from Africa), C. flavipes (originating from the Indo-Asia region but introduced into Africa and the New World), and C. nonagriae (from Australia and Papua New Guinea). Haplotype diversity of geographic populations relates to historical biogeographic barriers and biological control introductions, and reflects previous reports of ecological variation in these species. Strong discordance was found between the mitochondrial and nuclear markers in the Papua New Guinea haplotypes, which may be an outcome of hybridization and introgression of C. flavipes and C. nonagriae. The position of Cotesia flavipes from Japan was not well supported in any analysis and was the sister taxon to C. nonagriae (mtDNA, (*)BEAST), C. flavipes (nDNA) or C. flavipes+C. nonagriae (BEST) and, may represent a cryptic species. The concatenated five gene phylogenetic analyses did not support the overall separation and monophyly of clades associated with different host species, although some clades did show specific host associations, possibly due to localized host availability, rather than host specificity. Our results provide a framework for assessing whether distinct lineages represent cryptic species, and for examining parasitoid-host evolution and compatibility more generally. Given the limitations of morphological based identification for members of this complex, molecular identification is recommended prior to any biological control introductions.


Assuntos
Agentes de Controle Biológico , Variação Genética , Lepidópteros , Filogenia , Vespas/genética , Animais , Teorema de Bayes , Complexo IV da Cadeia de Transporte de Elétrons/genética , Genes Mitocondriais , Proteínas de Insetos/genética , Dados de Sequência Molecular , Tipagem de Sequências Multilocus , Proteína Relacionada ao Hormônio Paratireóideo , Fragmentos de Peptídeos , RNA Ribossômico 16S/genética
14.
Genome ; 55(3): 194-204, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22360780

RESUMO

The nearly complete mitochondrial (mt) genome of an egg parasitoid, Trissolcus basalis (Wollaston), was sequenced using both 454 and Illumina next-generation sequencing technologies. A portion of the noncoding region remained unsequenced, possibly owing to the presence of repeats. The sequenced portion of the genome is 15,768 bp and has a high A+T content (84.2%), as is typical for hymenopteran mt genomes. A total of 36 of the 37 genes normally present in animal mt genomes were located. The one exception was trnR; a truncated version of this gene is present between trnS(1) and nd5, but it is unclear whether this gene fragment could code for the entire trnR gene. The mt gene arrangement of T. basalis is different from other Proctotrupomorpha mt genomes, with a number of trn genes in different positions. However, no shared derived gene rearrangements were identified in the present study. Bayesian analyses of mt genomes from 29 hymenopteran taxa and seven other orders of holometabolous insects support some uncontroversial evolutionary relationships, but indicate that much higher levels of taxonomic sampling are necessary for the resolution of family and superfamily relationships.


Assuntos
Genoma Mitocondrial/genética , Filogenia , Vespas/genética , Sequência de Aminoácidos , Animais , Composição de Bases , Sequência de Bases , Teorema de Bayes , Códon/genética , Modelos Genéticos , Dados de Sequência Molecular , Alinhamento de Sequência , Análise de Sequência de DNA
15.
Zootaxa ; 5188(6): 559-573, 2022 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-37044760

RESUMO

The Pilbara and nearby regions in north-western Western Australia have an exceptionally high diversity of short-range endemic invertebrates inhabiting threatened groundwater-dependent habitats. Amphipod crustaceans, in particular, are dominant in these communities, but are poorly understood taxonomically, with many undescribed species. Recent molecular phylogenetic analyses of Pilbara eriopisid amphipods have, nonetheless, uncovered a previously unknown biodiversity. In this study, we formally establish a new genus, Pilbarana Stringer & King gen. nov., and describe two new species, P. grandis Stringer & King sp. nov. from Cane River Conservation Park and P. lowryi Stringer & King sp. nov. from the Fortescue River Basin near the Hamersley Range, using a combination of molecular and morphological data. The new genus is similar morphologically to the two additional Western Australian eriopisid genera, Nedsia Barnard & Williams, 1995 and Norcapensis Bradbury & Williams, 1997, but represents a genetically divergent, reciprocally monophyletic lineage, which can be differentiated by its vermiform body shape, the presence of an antennal sinus, and by the length and form of the antennae and uropods. This research signifies an important contribution to knowledge of Pilbara subterranean communities and has critical implications for future environmental impact assessments and conservation management.


Assuntos
Anfípodes , Animais , Austrália Ocidental , Austrália , Filogenia , Biodiversidade
16.
Sci Total Environ ; 820: 153223, 2022 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-35063529

RESUMO

Monitoring of biota is pivotal for the assessment and conservation of ecosystems. Environments worldwide are being continuously and increasingly exposed to multiple adverse impacts, and the accuracy and reliability of the biomonitoring tools that can be employed shape not only the present, but more importantly, the future of entire habitats. The analysis of environmental DNA (eDNA) metabarcoding data provides a quick, affordable, and reliable molecular approach for biodiversity assessments. However, while extensively employed in aquatic and terrestrial surface environments, eDNA-based studies targeting subterranean ecosystems are still uncommon due to the lack of accessibility and the cryptic nature of these environments and their species. Recent advances in genetic and genomic analyses have established a promising framework for shedding new light on subterranean biodiversity and ecology. To address current knowledge and the future use of eDNA methods in groundwaters and caves, this review explores conceptual and technical aspects of the application and its potential in subterranean systems. We briefly introduce subterranean biota and describe the most used traditional sampling techniques. Next, eDNA characteristics, application, and limitations in the subsurface environment are outlined. Last, we provide suggestions on how to overcome caveats and delineate some of the research avenues that will likely shape this field in the near future. We advocate that eDNA analyses, when carefully conducted and ideally combined with conventional sampling techniques, will substantially increase understanding and enable crucial expansion of subterranean community characterisation. Given the importance of groundwater and cave ecosystems for nature and humans, eDNA can bring to the surface essential insights, such as study of ecosystem assemblages and rare species detection, which are critical for the preservation of life below, as well as above, the ground.


Assuntos
DNA Ambiental , Ecossistema , Biodiversidade , Código de Barras de DNA Taxonômico , Monitoramento Ambiental/métodos , Humanos , Reprodutibilidade dos Testes
17.
Sci Rep ; 12(1): 16194, 2022 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-36171221

RESUMO

Subterranean habitats are generally very stable environments, and as such evolutionary transitions of organisms from surface to subterranean lifestyles may cause considerable shifts in physiology, particularly with respect to thermal tolerance. In this study we compared responses to heat shock at the molecular level in a geographically widespread, surface-dwelling water beetle to a congeneric subterranean species restricted to a single aquifer (Dytiscidae: Hydroporinae). The obligate subterranean beetle Paroster macrosturtensis is known to have a lower thermal tolerance compared to surface lineages (CTmax 38 °C cf. 42-46 °C), but the genetic basis of this physiological difference has not been characterized. We experimentally manipulated the thermal environment of 24 individuals to demonstrate that both species can mount a heat shock response at high temperatures (35 °C), as determined by comparative transcriptomics. However, genes involved in these responses differ between species and a far greater number were differentially expressed in the surface taxon, suggesting it can mount a more robust heat shock response; these data may underpin its higher thermal tolerance compared to subterranean relatives. In contrast, the subterranean species examined not only differentially expressed fewer genes in response to increasing temperatures, but also in the presence of the experimental setup employed here alone. Our results suggest P. macrosturtensis may be comparatively poorly equipped to respond to both thermally induced stress and environmental disturbances more broadly. The molecular findings presented here have conservation implications for P. macrosturtensis and contribute to a growing narrative concerning weakened thermal tolerances in obligate subterranean organisms at the molecular level.


Assuntos
Besouros , Animais , Besouros/genética , Ecossistema , Resposta ao Choque Térmico/genética , Transcriptoma
18.
Zootaxa ; 4949(1): zootaxa.4949.1.4, 2021 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-33756995

RESUMO

Involving the community in taxonomic research has the potential to increase the awareness, appreciation and value of taxonomy in the public sphere. We report here on a trial citizen science project, Insect Investigators, which partners taxonomists with school students to monitor Malaise traps and prioritise the description of new species collected. In this initial trial, four schools in regional South Australia participated in the program and all collected new species of the braconid subfamily Microgastrinae (Hymenoptera: Braconidae). These four species are here described as new, with the names being chosen in collaboration with the participating school students: Choeras ramcomarmorata Fagan-Jeffries Austin sp. nov., Glyptapanteles drioplanetus Fagan-Jeffries Austin sp. nov., Dolichogenidea franklinharbourensis Fagan-Jeffries Austin sp. nov. and Miropotes waikerieyeties Fagan-Jeffries Austin sp. nov. All four species are diagnosed against the known members of the genera from Australia, New Zealand, Fiji, Samoa and Papua New Guinea, and images and COI DNA barcodes are provided of the holotypes. Students had positive feedback about their experiences of the program, and there is significant potential for it to be expanded and used as a means to connect communities with taxonomic science.


Assuntos
Ciência do Cidadão , Himenópteros , Vespas , Animais , Instituições Acadêmicas , Austrália do Sul
19.
Evolution ; 75(1): 166-175, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33219700

RESUMO

Most subterranean animals are assumed to have evolved from surface ancestors following colonization of a cave system; however, very few studies have raised the possibility of "subterranean speciation" in underground habitats (i.e., obligate cave-dwelling organisms [troglobionts] descended from troglobiotic ancestors). Numerous endemic subterranean diving beetle species from spatially discrete calcrete aquifers in Western Australia (stygobionts) have evolved independently from surface ancestors; however, several cases of sympatric sister species raise the possibility of subterranean speciation. We tested this hypothesis using vision (phototransduction) genes that are evolving under neutral processes in subterranean species and purifying selection in surface species. Using sequence data from 32 subterranean and five surface species in the genus Paroster (Dytiscidae), we identified deleterious mutations in long wavelength opsin (lwop), arrestin 1 (arr1), and arrestin 2 (arr2) shared by a sympatric sister-species triplet, arr1 shared by a sympatric sister-species pair, and lwop and arr2 shared among closely related species in adjacent calcrete aquifers. In all cases, a common ancestor possessed the function-altering mutations, implying they were already adapted to aphotic environments. Our study represents one of the first confirmed cases of subterranean speciation in cave insects. The assessment of genes undergoing pseudogenization provides a novel way of testing modes of speciation and the history of diversification in blind cave animals.


Assuntos
Besouros/genética , Deriva Genética , Especiação Genética , Proteínas de Insetos/genética , Visão Ocular/genética , Animais , Arrestinas/genética , Água Subterrânea , Opsinas/genética
20.
PLoS One ; 16(9): e0256861, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34534224

RESUMO

Transcriptome-based exon capture approaches, along with next-generation sequencing, are allowing for the rapid and cost-effective production of extensive and informative phylogenomic datasets from non-model organisms for phylogenetics and population genetics research. These approaches generally employ a reference genome to infer the intron-exon structure of targeted loci and preferentially select longer exons. However, in the absence of an existing and well-annotated genome, we applied this exon capture method directly, without initially identifying intron-exon boundaries for bait design, to a group of highly diverse Haloniscus (Philosciidae), paraplatyarthrid and armadillid isopods, and examined the performance of our methods and bait design for phylogenetic inference. Here, we identified an isopod-specific set of single-copy protein-coding loci, and a custom bait design to capture targeted regions from 469 genes, and analysed the resulting sequence data with a mapping approach and newly-created post-processing scripts. We effectively recovered a large and informative dataset comprising both short (<100 bp) and longer (>300 bp) exons, with high uniformity in sequencing depth. We were also able to successfully capture exon data from up to 16-year-old museum specimens along with more distantly related outgroup taxa, and efficiently pool multiple samples prior to capture. Our well-resolved phylogenies highlight the overall utility of this methodological approach and custom bait design, which offer enormous potential for application to future isopod, as well as broader crustacean, molecular studies.


Assuntos
Proteínas de Artrópodes/genética , Éxons , Genoma , Isópodes/genética , Fases de Leitura Aberta , Animais , Proteínas de Artrópodes/classificação , Proteínas de Artrópodes/metabolismo , Conjuntos de Dados como Assunto , Expressão Gênica , Loci Gênicos , Genética Populacional , Sequenciamento de Nucleotídeos em Larga Escala , Íntrons , Isópodes/classificação , Filogenia
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