RESUMO
Decapod Crustacea exhibit a marine origin, but many taxa have occupied environments ranging from brackish to fresh water and terrestrial habitats, overcoming their inherent osmotic challenges. Osmotic and ionic regulation is achieved by the gill epithelia, driven by two active ATP-hydrolyzing ion transporters, the basal (Na+, K+)-ATPase and the apical V(H+)-ATPase. The kinetic characteristic of gill (Na+, K+)-ATPase and the mRNA expression of its α subunit have been widely studied in various decapod species under different salinity challenges. However, the evolution of the primary structure has not been explored, especially considering the functional modifications associated with decapod phylogeny. Here, we proposed a model for the topology of the decapod α subunit, identifying the sites and motifs involved in its function and regulation, as well as the patterns of its evolution assuming a decapod phylogeny. We also examined both the amino acid substitutions and their functional implications within the context of biochemical and physiological adaptation. The α-subunit of decapod crustaceans shows greater conservation (â¼94% identity) compared to the ß-subunit (â¼40%). While the binding sites for ATP and modulators are conserved in the decapod enzyme, the residues involved in the α-ß interaction are only partially conserved. In the phylogenetic context of the complete sequence of (Na+, K+)-ATPase α-subunit, most substitutions appear to be characteristic of the entire group, with specific changes for different subgroups, especially among brachyuran crabs. Interestingly, there was no consistent separation of α-subunit partial sequences related to habitat, suggesting that the convergent evolution for freshwater or terrestrial modes of life is not correlated with similar changes in the enzyme's primary amino acid sequence.
Assuntos
Sequência de Aminoácidos , Decápodes , Osmorregulação , Filogenia , ATPase Trocadora de Sódio-Potássio , Animais , ATPase Trocadora de Sódio-Potássio/genética , ATPase Trocadora de Sódio-Potássio/metabolismo , ATPase Trocadora de Sódio-Potássio/química , Osmorregulação/genética , Decápodes/genética , Decápodes/enzimologia , Decápodes/fisiologia , Evolução Molecular , Brânquias/metabolismo , Brânquias/enzimologiaRESUMO
BACKGROUND: The river prawn, Macrobrachium americanum (M. americanum), is one of the largest prawns of the genus in Latin America and is an amphidromous species distributed along the Pacific coast of America. This prawn has commercial value due to its size and taste, making it a good option for aquaculture production. Its culture has been attempted in ponds and concrete tanks, but no successful technique can still support commercial production. Understanding the mechanisms that regulate reproduction at the molecular level is very important. This knowledge can provide tools for manipulating transcripts, which could increase the number or size of animals in the culture. Our understanding of the mechanism that regulates the reproduction of M. americanum at the molecular level is limited. AIM: Perform and analyze the transcriptome assembly of the testes, vas deferens, and terminal ampulla of M. americanum. to provide new molecular information about its reproduction. METHODS AND RESULTS: The cDNA library was constructed and sequenced for each tissue to identify novel transcripts. A combined transcriptome with the three tissues was assembled using Trinity software. Unigenes were annotated using BLASTx and BLAST2GO. The transcriptome assembly generated 1,059,447 unigenes, of which 7222 genes had significant hits (e-value < 1 × 10-5) when compared against the Swiss-Prot database. Around 75 genes were related to sex determination, testis development, spermatogenesis, spermiogenesis, fertilization, maturation of testicular cells, neuropeptides, hormones, hormone receptors, and/or embryogenesis. CONCLUSIONS: These results provide new molecular information about M. americanum reproduction, representing a reference point for further genetic studies of this species.
Assuntos
Decápodes , Palaemonidae , Penaeidae , Animais , Masculino , Palaemonidae/genética , Perfilação da Expressão Gênica/métodos , Transcriptoma/genética , Decápodes/genética , Biblioteca Gênica , Penaeidae/genéticaRESUMO
The taxonomic status of the sergestid shrimp, Acetes americanus, has been questioned for several decades. No specific study has been performed thus far to resolve the incongruences. This species has a wide geographical range in the western Atlantic and is represented by two formally accepted subspecies: Acetes americanus carolinae, distributed in North America, and Acetes americanus americanus, present in South America. However, there are regions where the coexistence of both subspecies has been reported, such as Central America. This study aimed to genetically compare specimens of A. a. americanus collected in South America with A. a. carolinae sampled in North America to check for possible differences and the existence of more than one subspecies of A. americanus on the Brazilian coast. Based on the sequences of two informative markers, the cytochrome oxidase I region (COI) and 16S rRNA, phylogenetic reconstruction demonstrated well-defined clades with high support values, reinforcing the idea that A. a. americanus is genetically different from A. a. carolinae. Our hypothesis was corroborated as the specimens collected in Brazil were divided into two distinct lineages: the first composed of A. a. americanus sensu stricto (Brazil 1) and the second by Acetes americanus (Brazil 2). The three groups evidenced in the haplotype network were the same as those observed in the phylogenetic tree. The morphometric character (height/length of the thelycum) was effective in distinguishing A. a. Brazil 1 from A. a. carolinae. However, more detailed and conclusive studies comprising other characteristics to propose and describe a possible new entity are necessary. To the best of our knowledge, for the first time, the results of this study provide some insights into the taxonomic status of the sergestid shrimp A. americanus in the western Atlantic.
Assuntos
Decápodes , Animais , Filogenia , RNA Ribossômico 16S/genética , Decápodes/genética , Crustáceos/genética , Brasil , Variação GenéticaRESUMO
Species of the decapod family Palaemonidae are common components of tropical coastal waters and coral reefs. The majority of these species are symbionts of various invertebrate phyla. Despite a long history of research on their species diversity in the Dutch Caribbean, recent field expeditions have yielded much new information. Combined with examinations of specimens housed in Naturalis Biodiversity Center and information from literature, a comprehensive list of Dutch Carribean palaemonids is provided. Newly collected material was primarily identified via morphological analyses. Additional molecular phylogenetic analyses based on mitochondrial COI and 16S and nuclear Histone 3 (H3) genes were conducted in search of cryptic species on the one hand and to check conspecifity in species that were found on multiple host species on the other hand. In total, 46 species are here listed for the Dutch Caribbean of which 24 are here recorded for the first time for one of the islands. One species new to science was discovered and is herein described. Sixty new host associations are recorded. In light of biodiversity loss and increasing anthropogenic pressure on declining coral reefs, documenting the diversity of palaemonids and other coral reef species to provide baseline data takes on a new urgency.
Assuntos
Decápodes , Palaemonidae , Animais , Palaemonidae/genética , Filogenia , Decápodes/genética , Índias Ocidentais , Recifes de Corais , Região do Caribe , BiodiversidadeRESUMO
The genus Rimapenaeus Prez Farfante Kensley, 1997 occurs in shallow waters and includes six species, being four restricted to Pacific Ocean and two restricted to Atlantic Ocean. Along the Brazilian coast, Rimapenaeus constrictus (Stimpson, 1874) (called camaro ferrinho in Brazil) is one of the species most often accidentally caught during fishery activities, but due to its small size and abundance, it is not commercially exploited. Considering its wide distribution in the western Atlantic the purpose of this study was to examine from a molecular and morphological perspective specimens identified as R. constrictus sampled at the two extremes of its distribution (USA and southeastern Brazil). The phylogenetic trees (16S mtDNA and Cytochrome oxidase subunit I genes) showed a split of these specimens in two well-supported lineages: lineage A from USA (Maryland, Virginia, Florida and Gulf of Mexico) and lineage B from southeastern Brazil (Rio de Janeiro and So Paulo). The genetic distance observed between them (16S: 3.2%; COI: 9.4%) is high to be intraspecific, mainly when compared with other Dendrobranchiata studied. Instead of it none clear pattern that allows the morphological separation of these lineages was observed. We conclude that the shrimps usually called of Rimapenaeus constrictus, widely distributed in the Atlantic, actually represents two species and the Brazilian lineage probably is a new species, not described yet.
Assuntos
Decápodes , Penaeidae , Animais , Brasil , Decápodes/genética , Penaeidae/genética , FilogeniaRESUMO
Genome size (GS) or DNA nuclear content is considered a useful index for making inferences about evolutionary models and life history in animals, including taxonomic, biogeographical, and ecological scenarios. However, patterns of GS variation and their causes in crustaceans are still poorly understood. This study aimed to describe the GS of five Neotropical Synalpheus non-gambarelloides shrimps (S. apioceros, S. minus, S. brevicarpus, S. fritzmueller, and S. scaphoceris) and compare the C-values of all Caridea infraorder in terms of geography and phylogenetics. All animals were sampled in the coast of São Paulo State, Brazil, and GS was assessed by flow cytometry analysis (FCA). The C-values ranged from 7.89 pg in S. apioceros to 12.24 pg in S. scaphoceris. Caridean shrimps had higher GS than other Decapoda crustaceans. The results reveal a tendency of obtaining larger genomes in species with direct development in Synalpheus shrimps. In addition, a tendency of positive biogeographical (latitudinal) correlation with Caridea infraorder was also observed. This study provides remarkable and new protocol for FCA (using gating strategy for the analysis), which led to the discovery of new information regarding GS of caridean shrimps, especially for Neotropical Synalpheus, which represents the second-largest group in the Caridea infraorder.
Assuntos
Decápodes , Animais , Evolução Biológica , Brasil , Decápodes/genética , Tamanho do Genoma , FilogeniaRESUMO
This checklist is the fifth and last compilation on the decapod crustaceans reported to So Paulo (Brazil) coastal area, resulting from long-term multidisciplinary projects, which combined morphological analyses and molecular techniques. The current research includes 75 decapod species, herein referred as shrimps/lobsters-like (shrimps, ghost-shrimps, lobsters, and related groups), reported to So Paulo coastal area. These species occur in marine, estuarine, and amphidromous habitats and are classified into 21 families as follow: Aristeidae (2 spp., 2 genera), Atyidae (4 spp., 2 genera), Axianassidae (1 sp., 1 genus), Callianassidae (1 sp., 1 genus), Callichiridae (6 spp., 4 genera), Crangonidae (1 sp., 1 genus), Glyphocrangonidae (1 sp., 1 genus), Luciferidae (2 spp., 2 genera), Nephropidae (4 spp., 2 genera), Palaemonidae (15 spp., 9 genera), Palinuridae (2 spp., 1 genus), Pandalidae (1 sp., 1 genus), Pasiphaeidae (1 sp., 1 genus), Penaeidae (10 spp., 6 genera), Sergestidae (3 spp., 3 genera), Sicyoniidae (4 spp., 1 genus), Scyllaridae (5 spp., 3 genera), Solenoceridae (4 spp., 3 genera), Stenopodidae (2 spp., 1 genus), and Upogebiidae (6 spp., 1 genus). We generated new sequences of cytochrome oxidase subunit I (barcode region) and 16S genes (51 and 54, respectively) of 54 species. Our examination concluded that 75 shrimps/lobsters-like species are reported to the So Paulo coast. We excluded Leander tenuicornis (Palaemonidae), Penaeus setiferus (Penaeidae), Philocheras gorei (Crangonidae), and Rhynchocinetes typus (Rhynchocinetidae) from this list.
Assuntos
Crangonidae , Decápodes , Penaeidae , Animais , Brasil , Decápodes/genética , Humanos , FilogeniaRESUMO
The Yucatán Peninsula, Mexico is a carbonate platform well-known for extensive karst networks of densely stratified aquifer ecosystems. This aquifer supports diverse anchialine fauna, including species of the globally distributed anchialine shrimp genus Typhlatya (Atyidae). Four species (T. campecheae, T. pearsei, T. dzilamensis and T. mitchelli) are endemic to the Peninsula, of which three are federally listed in Mexico. This first integrative evaluation (i.e., molecular, morphological, broad geographic and type locality sampling, and environmental data) of Yucatán Typhlatya reveals considerable species identity conflict in prior phylogenetic assessments, broad species ranges, syntopy within cave systems and five genetic lineages (of which two are new to science). Despite sampling from the type locality of endangered T. campecheae, specimens (and molecular data) were indistinguishable from vulnerable T. pearsei. Ancestral/divergence reconstructions support convergent evolution of a low-salinity ancestor for a post-Paleogene arc Yucatán + Cuba Typhlatya clade within the anchialine Atyidae clade. A secondary adaptation for the coastal-restricted euryhaline (2-37 psu), Typhlatya dzilamensis (unknown conservation status) was identified, while remaining species lineages were low-salinity (< 5 psu) adapted and found within the meteoric lens of inland and coastal caves. This study demonstrates the need for integrative/interdisciplinary approaches when conducting biodiversity assessments in complex and poorly studied aquifers.
Assuntos
Decápodes , Água Subterrânea , Animais , Decápodes/genética , Ecossistema , México , FilogeniaRESUMO
Thor amboinensis (De Man, 1888), known as sexy shrimp or anemone squat shrimp and popular among divers and aquarists, was previously believed to have a worldwide distribution, with populations throughout the tropical parts of the Indo-Pacific and Atlantic Ocean. However, consistent differences in some details of the colour pattern strongly suggest that T. amboinensis does not represent a single species, but a pantropical species complex. A recent phylogeographic analysis of T. amboinensis based on molecular data confirmed that this taxon is composed of at least five putative cryptic or pseudocryptic species. In the present study, a new cryptic species, Thor dicaprio sp. nov., is established for the western Atlantic populations previously referred to as T. amboinensis. The new species can be distinguished from all other members of the T. amboinensis complex by two differences in the colour pattern and a subtle difference in the size and setation of the appendix masculina, the latter yet to be confirmed. The conspicuous red-white banding of the antennal flagella appears to be the most diagnostic feature of the new species. In addition, T. dicaprio sp. nov. forms a genetically distinctive, homogeneous, tropical western Atlantic (TWA) clade, with the COI pairwise genetic distances from other clades ranging from 8.8% to 19.2%. The distribution of T. dicaprio sp. nov. includes the entire Caribbean Sea, parts of the Gulf of Mexico, Florida, Bahamas, Bermuda, as well as some offshore localities off northern and eastern Brazil. The main aspects and biology and ecological variability of T. dicaprio sp. nov. are discussed in the light of phylogeographic data presently available for the T. amboinensis complex.
Assuntos
Decápodes , Distribuição Animal , Estruturas Animais , Animais , Decápodes/genéticaRESUMO
BACKGROUND: The formation of the Isthmus of Panama and final closure of the Central American Seaway (CAS) provides an independent calibration point for examining the rate of DNA substitutions. This vicariant event has been widely used to estimate the substitution rate across mitochondrial genomes and to date evolutionary events in other taxonomic groups. Nuclear sequence data is increasingly being used to complement mitochondrial datasets for phylogenetic and evolutionary investigations; these studies would benefit from information regarding the rate and pattern of DNA substitutions derived from the nuclear genome. RESULTS: To estimate the genome-wide neutral mutation rate (µ), genotype-by-sequencing (GBS) datasets were generated for three transisthmian species pairs in Alpheus snapping shrimp. A range of bioinformatic filtering parameters were evaluated in order to minimize potential bias in mutation rate estimates that may result from SNP filtering. Using a Bayesian coalescent approach (G-PhoCS) applied to 44,960 GBS loci, we estimated µ to be 2.64E-9 substitutions/site/year, when calibrated with the closure of the CAS at 3 Ma. Post-divergence gene flow was detected in one species pair. Failure to account for this post-split migration inflates our substitution rate estimates, emphasizing the importance of demographic methods that can accommodate gene flow. CONCLUSIONS: Results from our study, both parameter estimates and bioinformatic explorations, have broad-ranging implications for phylogeographic studies in other non-model taxa using reduced representation datasets. Our best estimate of µ that accounts for coalescent and demographic processes is remarkably similar to experimentally derived mutation rates in model arthropod systems. These results contradicted recent suggestions that the closure of the Isthmus was completed much earlier (around 10 Ma), as mutation rates based on an early calibration resulted in uncharacteristically low genomic mutation rates. Also, stricter filtering parameters resulted in biased datasets that generated lower mutation rate estimates and influenced demographic parameters, serving as a cautionary tale for the adherence to conservative bioinformatic strategies when generating reduced-representation datasets at the species level. To our knowledge this is the first use of transisthmian species pairs to calibrate the rate of molecular evolution from GBS data.