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1.
BMC Genomics ; 20(1): 531, 2019 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-31253104

RESUMO

BACKGROUND: The Crustacea are an evolutionarily diverse taxon which underpins marine food webs and contributes significantly to the global economy. However, our knowledge of crustacean endocrinology and development is far behind that of terrestrial arthropods. Here we present a unique insight into the molecular pathways coordinating crustacean metamorphosis, by reconciling nuclear receptor (NR) gene activity from a 12-stage, 3-replicate transcriptome in the ornate spiny lobster (Panulirus ornatus) during larval development. RESULTS: We annotated 18 distinct nuclear receptor genes, including three novel NRs which are upregulated prior to metamorphosis and have hence been named the "molt-associated receptors" (MARs). We also demonstrate the ecdysone-responsive expression of several known molt-related NRs including ecdysone receptor, fushi-tarazu-F1 and E75. Phylogenetic analysis of the curated NR family confirmed gene annotations and suggested that the MARs are a recent addition to the crustacean superfamily, occurring across the Malacostraca from the Stomatopoda to the Decapoda. The ligand-binding domain of these receptors appears to be less conserved than that of typical group-1 NRs. Expression data from two other crustacean species was utilized to examine MAR expression. The Y-organ of the tropical land crab showed a decline in expression of all MARs from intermolt to post-molt. Tissue distributions showed gonad-enriched expression in the Eastern rock lobster and antennal gland-enriched expression in the tropical land crab, although expression was evident across most tissues. CONCLUSION: By mining transcriptome data, we have curated an extensive list of NR genes expressed during the metamorphic molts of P. ornatus, including three novel crustacean NRs which appear to play a role in the molting process. Divergence of the E-region of these new receptors indicates that they may have adopted a function that is unconventional for NRs. Based on expression patterns, we can confirm that a number of NRs play a role in the ecdysone cassette which regulates molting in crustaceans. This study describes in detail the molecular events surrounding crustacean molting and metamorphosis by taking advantage of the distinctive life history unique to achelatan crustaceans.


Assuntos
Perfilação da Expressão Gênica , Metamorfose Biológica/genética , Palinuridae/crescimento & desenvolvimento , Palinuridae/genética , Receptores Citoplasmáticos e Nucleares/genética , Animais , Muda/genética , Homologia de Sequência do Ácido Nucleico , Especificidade da Espécie
2.
Sci Rep ; 9(1): 7100, 2019 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-31068625

RESUMO

The assessment of the mechanisms and patterns of larval connectivity between geographically separated populations leads to a better understanding of benthic marine population dynamics, especially in commercially valuable species. This study investigated for the first time the fine-scale temporal genetic variability of new settlers and their origins in a benthic marine organism with one of the longest pelagic larval phases, the Caribbean spiny lobster (Panulirus argus). We genotyped newly settled postlarvae in the Florida Keys and adults of spiny lobster from the Florida Keys and throughout the Caribbean Sea. We identified strong larval connectivity between Dominican Republic, Belize, Nicaragua, the Florida Keys, and West-Florida. The larval dispersal modeling suggests that Florida's lobster population could receive recruits from within and from other areas outside its state and national maritime boundaries. The genetic analyses refine the oceanographic model indicating that the connectivity patterns described could also result from unknown parental populations sourcing adults and postlarvae in different spawning seasons to the Florida Keys. We discuss the importance of small temporal scales to identify patterns in larval export. Our findings are significant on two levels. From the larval dispersal perspective, genetic results and biophysical modeling identify patterns of gene flow enhancing persistence of local populations. From an economic and fishery perspective, P. argus is the most important commercial species in the Caribbean and our results inform how considering larval source and sink dynamics across international boundaries could improve management plans at local, national, and regional levels.


Assuntos
Fluxo Gênico , Larva/genética , Biologia Marinha/métodos , Palinuridae/genética , Animais , Região do Caribe , Pesqueiros/economia , Florida , Loci Gênicos , Variação Genética , Genótipo , Técnicas de Genotipagem , Modelos Biológicos , Dinâmica Populacional
3.
Sci Rep ; 8(1): 17690, 2018 12 06.
Artigo em Inglês | MEDLINE | ID: mdl-30523272

RESUMO

Panulirus argus is a keystone species and target of the most lucrative fishery in the Caribbean region. This study reports, for the first time, the complete mitochondrial genome of Panulirus argus (average coverage depth nucleotide-1 = 70×) assembled from short Illumina 150 bp PE reads. The AT-rich mitochondrial genome of Panulirus argus was 15 739 bp in length and comprised 13 protein-coding genes (PCGs), 2 ribosomal RNA genes, and 22 transfer RNA genes. A single 801 bp long intergenic space was assumed to be the D-loop. Most of the PCGs were encoded on the H-strand. The gene order observed in the mitochondrial genome of Panulirus argus corresponds to the presumed Pancrustacean ground pattern. KA/KS ratios calculated for all mitochondrial PCGs showed values < 1, indicating that all these PCGs are evolving under purifying selection. A maximum likelihood phylogenetic analysis (concatenated PCGs [n = 13], 154 arthropods) supported the monophyly of the Achelata and other infraorders within the Decapoda. Mitochondrial PCGs have enough phylogenetic informativeness to explore high-level genealogical relationships in the Pancrustacea. The complete mitochondrial genome of the Caribbean spiny lobster Panulirus argus will contribute to the better understanding of meta-population connectivity in this keystone overexploited species.


Assuntos
Decápodes/genética , Genoma Mitocondrial/genética , Palinuridae/genética , Animais , Região do Caribe , Feminino , Ordem dos Genes/genética , Filogenia , RNA Ribossômico/genética , RNA de Transferência/genética , Alimentos Marinhos
4.
BMC Genomics ; 19(1): 690, 2018 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-30231936

RESUMO

BACKGROUND: The scalloped spiny lobster (Panulirus homarus) is a popular seafood commodity worldwide and an important export item from Oman. Annual catches in commercial fisheries are in serious decline, which has resulted in calls for the development of an integrated stock management approach. In Oman, the scalloped spiny lobster is currently treated as a single management unit (MU) or stock and there is an absence of information on the genetic population structure of the species that can inform management decisions, particularly at a fine-scale level. This work is the first to identify genome-wide single nucleotide polymorphisms (SNPs) for P. homarus using Diversity Arrays Technology sequencing (DArT-seq) and to elucidate any stock structure in the species. RESULTS: After stringent filtering, 7988 high utility SNPs were discovered and used to assess the genetic diversity, connectivity and structure of P. homarus populations from Al Ashkharah, Masirah Island, Duqm, Ras Madrakah, Haitam, Ashuwaymiyah, Mirbat and Dhalkut landing sites. Pairwise FST estimates revealed low differentiation among populations (pairwise FST range = - 0.0008 - 0.0021). Analysis of genetic variation using putatively directional FST outliers (504 SNPs) revealed higher and significant pairwise differentiation (p < 0.01) for all locations, with Ashuwaymiyah being the most diverged population (Ashuwaymiyah pairwise FST range = 0.0288-0.0736). Analysis of population structure using Discriminant Analysis of Principal Components (DAPC) revealed a broad admixture among P. homarus, however, Ashuwaymiyah stock appeared to be potentially under local adaptive pressures. Fine scale analysis using Netview R provided further support for the general admixture of P. homarus. CONCLUSIONS: Findings here suggested that stocks of P. homarus along the Omani coastline are admixed. Yet, fishery managers need to treat the lobster stock from Ashuwaymiyah with caution as it might be subject to local adaptive pressures. We emphasize further study with larger number of samples to confirm the genetic status of the Ashuwaymiyah stock. The approach utilised in this study has high transferability in conservation and management of other marine stocks with similar biological and ecological attributes.


Assuntos
Adaptação Fisiológica , Fluxo Gênico , Marcadores Genéticos , Genoma , Palinuridae/genética , Polimorfismo de Nucleotídeo Único , Animais , Genética Populacional
5.
PLoS One ; 13(9): e0203935, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30240423

RESUMO

The spiny lobster, Panulirus argus, has two classes of chemosensilla representing "olfaction" and "distributed chemoreception," as is typical for decapod crustaceans. Olfactory sensilla are found exclusively on antennular lateral flagella and are innervated only by olfactory receptor neurons (ORNs) that project into olfactory lobes organized into glomeruli in the brain. Distributed chemoreceptor sensilla are found on all body surfaces including the antennular lateral flagella (LF) and walking leg dactyls (dactyls), and are innervated by both chemoreceptor neurons (CRNs) and mechanoreceptor neurons that project into somatotopically organized neuropils. Here, we examined expression of three classes of chemosensory genes in transcriptomes of the LF (with ORNs and CRNs), dactyls (with only CRNs), and brain of P. argus: Ionotropic Receptors (IRs), which are related to ionotropic glutamate receptors and found in all protostomes including crustaceans; Gustatory Receptors (GRs), which are ionotropic receptors that are abundantly expressed in insects but more restricted in crustaceans; and Transient Receptor Potential (TRP) channels, a diverse set of sensor-channels that include several chemosensors in diverse animals. We identified 108 IRs, one GR, and 18 homologues representing all seven subfamilies of TRP channels. The number of IRs expressed in the LF is far greater than in dactyls, possibly reflecting the contribution of receptor proteins associated with the ORNs beyond those associated with CRNs. We found co-receptor IRs (IR8a, IR25a, IR76b, IR93a) and conserved IRs (IR21a, IR40a) in addition to the numerous divergent IRs in the LF, dactyl, and brain. Immunocytochemistry showed that IR25a is expressed in ORNs, CRNs, and a specific type of cell located in the brain near the olfactory lobes. While the function of IRs, TRP channels, and the GR was not explored, our results suggest that P. argus has an abundance of diverse putative chemoreceptor proteins that it may use in chemoreception.


Assuntos
Células Quimiorreceptoras/fisiologia , Palinuridae/fisiologia , Sequência de Aminoácidos , Animais , Encéfalo/fisiologia , Feminino , Perfilação da Expressão Gênica , Imuno-Histoquímica , Masculino , Neurônios Receptores Olfatórios/fisiologia , Palinuridae/anatomia & histologia , Palinuridae/genética , Filogenia , Receptores Ionotrópicos de Glutamato/genética , Receptores Ionotrópicos de Glutamato/fisiologia , Homologia de Sequência de Aminoácidos , Canais de Receptores Transientes de Potencial/genética , Canais de Receptores Transientes de Potencial/fisiologia
6.
BMC Genet ; 19(1): 27, 2018 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-29728054

RESUMO

BACKGROUND: One of the major impediments to spiny lobster aquaculture is the high cost of hatchery production due to the long and complex larval cycle and poor survival during the many moult stages, especially at metamorphosis. We examined if the key trait of larval survival can be improved through selection by determining if genetic variance exists for this trait. Specifically, we report, for the first time, genetic parameters (heritability and correlations) for early survival rates recorded at five larval phases; early-phyllosoma stages (instars 1-6; S1), mid-phyllosoma stages (instars; 7-12; S2), late-phyllosoma stages (instars 13-17; S3), metamorphosis (S4) and puerulus stage (S5) in hatchery-reared spiny lobster Sagmariasus verreauxi. RESULTS: The data were collected from a total of 235,060 larvae produced from 18 sires and 30 dams over nine years (2006 to 2014). Parentage of the offspring and full-sib families was verified using ten microsatellite markers. Analysis of variance components showed that the estimates of heritability for all the five phases of larval survival obtained from linear mixed model were generally similar to those obtained from threshold logistic generalised models (0.03-0.47 vs. 0.01-0.50). The heritability estimates for survival traits recorded in the early larval phases (S1 and S2) were higher than those estimated in later phases (S3, S4 and S5). The existence of the additive genetic component in larval survival traits indicate that they could be improved through selection. Both phenotypic and genetic correlations among the five survival measures studied were moderate to high and positive. The genetic associations between successive rearing periods were stronger than those that are further apart. CONCLUSIONS: Our estimates of heritability and genetic correlations reported here in a spiny lobster species indicate that improvement in the early survival especially during metamorphosis can be achieved through genetic selection in this highly economic value species.


Assuntos
Metamorfose Biológica/genética , Palinuridae/crescimento & desenvolvimento , Palinuridae/genética , Animais , Aquicultura , Hereditariedade , Larva/crescimento & desenvolvimento , Seleção Genética
8.
Mol Ecol ; 27(1): 54-65, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29134719

RESUMO

Population structure of many marine organisms is spatially patchy and varies within and between years, a phenomenon defined as chaotic genetic patchiness. This results from the combination of planktonic larval dispersal and environmental stochasticity. Additionally, in species with bi-partite life, postsettlement selection can magnify these genetic differences. The high fecundity (up to 500,000 eggs annually) and protracted larval duration (12-24 months) and dispersal of the southern rock lobster, Jasus edwardsii, make it a good test species for chaotic genetic patchiness and selection during early benthic life. Here, we used double digest restriction site-associated DNA sequencing (ddRADseq) to investigate chaotic genetic patchiness and postsettlement selection in this species. We assessed differences in genetic structure and diversity of recently settled pueruli across four settlement years and between two sites in southeast Australia separated by approximately 1,000 km. Postsettlement selection was investigated by identifying loci under putative positive selection between recently settled pueruli and postpueruli and quantifying differences in the magnitude and strength of the selection at each year and site. Genetic differences within and among sites through time in neutral SNP markers indicated chaotic genetic patchiness. Recently settled puerulus at the southernmost site exhibited lower genetic diversity during years of low puerulus catches, further supporting this hypothesis. Finally, analyses of outlier SNPs detected fluctuations in the magnitude and strength of the markers putatively under positive selection over space and time. One locus under putative positive selection was consistent at both locations during the same years, suggesting the existence of weak postsettlement selection.


Assuntos
Variação Genética , Genética Populacional , Palinuridae/genética , Animais , Austrália , Geografia , Heterozigoto , Polimorfismo de Nucleotídeo Único/genética , Seleção Genética , Análise de Sequência de DNA , Tasmânia , Fatores de Tempo
9.
Dev Biol ; 430(2): 337-345, 2017 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-28864068

RESUMO

Sex determination pathways are extensively diverse across species, with the master sex-determinants being the most variable element. Despite this, there is a family of DM-domain transcription factors (Dmrts), which hold a highly conserved function in sexual development. This work is the first to describe a heterogametic sex-linked Dmrt in an invertebrate species, the Eastern spiny lobster, Sagmariasus verreauxi. We have termed the Y-linked, truncated paralogue of the autosomal iDmrt1, Sv-iDMY. Considering the master sex-determining function of both DMY in medaka and DM-W in frog, we hypothesised a similar function of Sv-iDMY. By conducting temporal expression analyses during embryogenesis we have identified a putative male sex-determining period during which iDMY>iDmrt1. Employing a GAL4-transactivation assay we then demonstrate the dominant negative suppression of iDMY over its autosomal iDmrt1 paralogue, suggesting the mechanism with which iDMY determines sex. Comparative analyses of Sv-iDMY, DM-W and medaka DMY, highlight the C'-mediated features of oligomerisation and transactivation as central to the mechanism that each exerts. Indeed, these features may underpin the plasticity facilitating the convergent emergence of these three sporadic sex-linked master-Dmrts.


Assuntos
Genes Ligados ao Cromossomo Y , Palinuridae/genética , Fatores de Transcrição/genética , Cromossomo Y/genética , Animais , Antenas de Artrópodes/metabolismo , Feminino , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Masculino , Oryzias/genética , Domínios Proteicos , Especificidade da Espécie , Testículo/metabolismo , Fatores de Transcrição/química , Fatores de Transcrição/fisiologia , Ativação Transcricional , Xenopus laevis/genética
10.
BMC Evol Biol ; 17(1): 195, 2017 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-28821229

RESUMO

BACKGROUND: There is increasing recognition of the concordance between marine biogeographic and phylogeographic boundaries. However, it is still unclear how population-level divergence translates into species-level divergence, and what are the principal factors that first initiate that divergence, and then maintain reproductive isolation. This study examines the likely forces driving population and lineage divergences in the broadly-distributed Indo-Pacific spiny lobster Panulirus homarus, which has peripheral divergent lineages in the west and east. The study focuses particularly on the West Indian Ocean, which is emerging as a region of unexpected diversity. Mitochondrial control region (mtCR) and COI sequences as well as genotypes of 9 microsatellite loci were examined in 410 individuals from 17 locations grouped into 7 regions from South Africa in the west, and eastward across to Taiwan and the Marquesas Islands. Phylogenetic and population-level analyses were used to test the significance and timing of divergences and describe the genetic relationships among populations. RESULTS: Analyses of the mtCR revealed high levels of divergence among the seven regions (ФST = 0.594, P < 0.001). Microsatellite analyses also revealed significant divergence among regions, but at a much lower level (FST = 0.066, P < 0.001). The results reveal different patterns of mtCR v. nDNA divergence between the two distinct peripheral lineages: a subspecies in South Africa and Madagascar, and a phylogeographically diverged population in the Marquesas. The results also expose a number of other more fine-scale population divergences, particularly in the Indian Ocean. CONCLUSIONS: The divergence of peripheral lineages in the west and east of the species' range appear to have been initiated and maintained by very different processes. The pattern of mitochondrial and nuclear divergence of the western lineage, implicates processes of parapatric isolation, secondary contact and introgression, and suggests possible maintenance through adaptation and behavioural reproductive isolation. In contrast, the eastern lineage appears to have diverged through a rare colonisation event, maintained through long-term isolation, and matches expectations of the core-periphery hypothesis. The process of active peripheral speciation may be a common force in the Indo-Pacific that helps drive some of the regions' recognized biogeographic boundaries.


Assuntos
Palinuridae/classificação , Filogeografia , Animais , DNA Mitocondrial/genética , Geografia , Haplótipos/genética , Oceano Índico , Repetições de Microssatélites/genética , Oceano Pacífico , Palinuridae/genética , Filogenia , Análise de Componente Principal , Especificidade da Espécie
11.
Sci Rep ; 7(1): 6781, 2017 07 28.
Artigo em Inglês | MEDLINE | ID: mdl-28754989

RESUMO

Double digest restriction site-associated DNA sequencing (ddRADseq) and target capture sequencing methods are used to explore population and phylogenetic questions in non-model organisms. ddRADseq offers a simple and reliable protocol for population genomic studies, however it can result in a large amount of missing data due to allelic dropout. Target capture sequencing offers an opportunity to increase sequencing coverage with little missing data and consistent orthologous loci across samples, although this approach has generally been applied to conserved markers for deeper evolutionary questions. Here, we combine both methods to generate high quality sequencing data for population genomic studies of all marine lobster species from the genus Jasus. We designed probes based on ddRADseq libraries of two lobster species (Jasus edwardsii and Sagmariasus verreauxi) and evaluated the captured sequencing data in five other Jasus species. We validated 4,465 polymorphic loci amongst these species using a cost effective sequencing protocol, of which 1,730 were recovered from all species, and 4,026 were present in at least three species. The method was also successfully applied to DNA samples obtained from museum specimens. This data will be further used to assess spatial-temporal genetic variation in Jasus species found in the Southern Hemisphere.


Assuntos
Palinuridae/genética , Análise de Sequência de DNA/métodos , Animais , Sondas de DNA/metabolismo , Loci Gênicos , Variação Genética , Genoma , Genótipo , Polimorfismo de Nucleotídeo Único/genética , Análise de Componente Principal , Especificidade da Espécie
12.
Anim Biotechnol ; 27(4): 310-4, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27565876

RESUMO

Polymorphic microsatellite loci were isolated for Panulirus ornatus using 454 GS-FLX Titanium pyrosequencing. Fifteen markers containing perfect di-, tri-, tetra-, and penta-nucleotide motifs were consistently co-amplified in five multiplexes in a panel of 91 randomly selected samples. Observed number of alleles varied from 2 to 14 per locus. Observed and expected heterozygosity ranged from 0.090 to 0.79 and 0.08 to 0.87, respectively. Ten loci deviated from Hardy-Weinberg equilibrium after sequential Bonferroni correction. Genetic linkage disequilibrium analysis between all pairs of the loci showed significant departure from the null hypothesis between 11 loci. The microsatellite markers were also amplified successfully in related Panulirus homarus species with adequate level of polymorphism. The successful cross-species primer amplification of the 15 microsatellites indicates the potential of the developed markers to be transferred to other Panulirus species. The 15 novel microsatellite markers reported in this work add to the previously characterized markers by our group, exhibit adequate levels of polymorphism for wide range of future studies investigating population structure, genetic diversity, and evolutionary relationships among Panulirus species.


Assuntos
Marcadores Genéticos/genética , Repetições de Microssatélites/genética , Palinuridae/genética , Animais , Especificidade da Espécie
13.
PLoS One ; 11(7): e0158919, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27391425

RESUMO

Alpha-amylases are ubiquitously distributed throughout microbials, plants and animals. It is widely accepted that omnivorous crustaceans have higher α-amylase activity and number of isoforms than carnivorous, but contradictory results have been obtained in some species, and carnivorous crustaceans have been less studied. In addition, the physiological meaning of α-amylase polymorphism in crustaceans is not well understood. In this work we studied α-amylase in a carnivorous lobster at the gene, transcript, and protein levels. It was showed that α-amylase isoenzyme composition (i.e., phenotype) in lobster determines carbohydrate digestion efficiency. Most frequent α-amylase phenotype has the lowest digestion efficiency, suggesting this is a favoured trait. We revealed that gene and intron loss have occurred in lobster α-amylase, thus lobsters express a single 1830 bp cDNA encoding a highly conserved protein with 513 amino acids. This protein gives rise to two isoenzymes in some individuals by glycosylation but not by limited proteolysis. Only the glycosylated isoenzyme could be purified by chromatography, with biochemical features similar to other animal amylases. High carbohydrate content in diet down-regulates α-amylase gene expression in lobster. However, high α-amylase activity occurs in lobster gastric juice irrespective of diet and was proposed to function as an early sensor of the carbohydrate content of diet to regulate further gene expression. We concluded that gene/isoenzyme simplicity, post-translational modifications and low Km, coupled with a tight regulation of gene expression, have arose during evolution of α-amylase in the carnivorous lobster to control excessive carbohydrate digestion in the presence of an active α-amylase.


Assuntos
Proteínas de Artrópodes , Carnivoridade/fisiologia , Regulação Enzimológica da Expressão Gênica/fisiologia , Palinuridae , alfa-Amilases , Animais , Proteínas de Artrópodes/biossíntese , Proteínas de Artrópodes/genética , DNA Complementar/genética , DNA Complementar/metabolismo , Glicosilação , Isoenzimas/biossíntese , Isoenzimas/genética , Palinuridae/genética , Palinuridae/metabolismo , Proteólise , alfa-Amilases/biossíntese , alfa-Amilases/genética
14.
Zootaxa ; 4107(3): 353-66, 2016 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-27394825

RESUMO

Genetic analysis divides Panulirus argus into two different species, physically separated by the Amazon-Orinoco plume since the Last Glacial Maximum. Panulirus argus sensu stricto is distributed north of this biogeographic barrier and the second species to the south, occurring in Brazil. The Panulirus species in the Atlantic Ocean are being overfished and the standing stocks are unknown and still not considered endangered or threatened due to a deficiency of precise abundance data. The lack of data makes it impossible to undertake an effective conservation and management policy. In order to assist in the future management and conservation of the Spiny Lobster in the Atlantic Ocean and particularly for the indigenous species from Brazilian waters, this study formally recognizes and describes a new species, Panulirus meripurpuratus sp. nov., for what was previously known as P. argus in Brazilian waters, and differentiates it from Panulirus argus from North American waters and the Caribbean Sea. The work also presents an overview of the biogeographic distribution of the species and presents two identification keys to Atlantic species, one based on morphology and the other on live colouration.


Assuntos
Distribuição Animal , Palinuridae/anatomia & histologia , Palinuridae/classificação , Animais , Oceano Atlântico , Brasil , Feminino , Masculino , Palinuridae/genética , Palinuridae/fisiologia , Especificidade da Espécie
15.
Integr Comp Biol ; 56(6): 1144-1156, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27252217

RESUMO

The decapod Crustacea are the most species-rich order of the Crustacea and include some of the most charismatic and highly valued commercial species. Thus the decapods draw a significant research interest in relation to aquaculture, as well as gaining a broader understanding of these species' biology. However, the diverse physiology of the group considered with the lack of a model species have presented an obstacle for comparative analyses. In reflection of this, the recent integration of comparative transcriptomics has rapidly advanced our understanding of key regulatory pathways and developmental phenomena, an example being our understanding of sexual development. We discuss our work in the Eastern spiny lobster, Sagmariasus verreauxi, in the context of what is currently known about male sexual development in the decapods, highlighting the importance of transcriptomic techniques in achieving our recent advancements. We describe the progression made in our understanding of male sexual differentiation and maturation, as mediated by the insulin-like androgenic gland hormone (IAG), integrating the role of regulatory binding proteins (IGFBPs), a tyrosine kinase insulin receptor (TKIR), as well as the upstream effect of neuroendocrine hormones (GIH and MIH). We then consider the less well understood mechanism of male sex determination, with an emphasis on what we believe to be the key regulatory factors, the Dsx- and mab-3-related transcription factors (Dmrts). Finally, we discuss the function of the antennal gland (AnG) in sexual development, relating to the emergence of male-biased upregulation in the AnG in later sexual maturation and the sexually dimorphic expression of two key genes Sv-TKIR and Sv-Dmrt1 We then present the AnG as a case study to illustrate how comparative transcriptomic techniques can be applied to guide preliminary analyses, like the hypothesis that the AnG may function in pheromone biosynthesis. In summary, we describe the power of transcriptomics in facilitating the progress made in our understanding of male sexual development, as illustrated by the commercial decapod species, S. verreauxi Considering future directions, we suggest that the integration of multiple omics-based techniques offers the most powerful tool to ensure we continue to piece together the biology of the important group of decapod Crustacea.


Assuntos
Palinuridae/crescimento & desenvolvimento , Palinuridae/genética , Diferenciação Sexual/genética , Desenvolvimento Sexual/genética , Transcriptoma , Animais , Masculino
16.
Genet Mol Res ; 15(2)2016 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-27173289

RESUMO

Fourteen polymorphic microsatellites with perfect di-, tri-, and tetra-nucleotide repeats were identified for Panulirus homarus using Roche 454 whole-genome sequencing method. Microsatellites were efficiently co-amplified in four multiplexes and a singleplex, providing consistent and easily interpretable genotypes. The number of alleles per locus ranged from 2 to 11 with the observed and expected heterozygosity ranging between 0.000-0.532 and 0.031-0.836, respectively. A significant deviation from Hardy-Weinberg equilibrium was observed for majority of the loci, probably due to homozygote excess. Genetic linkage disequilibrium analysis between all the possible pairs of the loci showed significant departure from the null hypothesis in the loci pairs Pho-G11-Pho-G33 and Pho-G33-Pho-G57. High success in primer cross-species amplification of these microsatellite markers indicates their utility for genetic studies of different Panulirus species.


Assuntos
Repetições de Microssatélites , Palinuridae/genética , Polimorfismo Genético , Animais , Marcadores Genéticos , Genótipo , Heterozigoto , Desequilíbrio de Ligação
17.
Gen Comp Endocrinol ; 229: 8-18, 2016 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-26883686

RESUMO

In crustaceans the insulin-like androgenic gland hormone (IAG) is responsible for male sexual differentiation. To date, the biochemical pathways through which IAG exerts its effects are poorly understood and could be elucidated through the production of a functional recombinant IAG (rIAG). We have successfully expressed glycosylated, biologically active IAG using the Pichia pastoris yeast expression system. We co-expressed recombinant single-chain precursor molecules consisting of the B and A chains (the mature hormone) tethered by a flexible linker, producing rIAGs of the following commercially important species: Eastern spiny lobster Sagmariasus verreauxi (Sv), redclaw crayfish Cherax quadricarinatus (Cq) and giant freshwater prawn Macrobrachium rosenbergii (Mr). We then tested the biological activity of each, through the ability to increase phosphorylation in the testis; both Sv and Cq rIAGs significantly elevated phosphorylation specific to their species, and in a dose-dependent manner. Mr rIAG was tested on Macrobrachium australiense (Ma), eliciting a similar response. Moreover, using bioinformatics analyses of the de novo assembled spiny lobster transcriptome, we identified a spiny lobster tyrosine kinase insulin receptor (Sv-TKIR). We validated this discovery with a receptor activation assay in COS-7 cells expressing Sv-TKIR, using a reporter SRE-LUC system designed for RTKs, with each of the rIAG proteins acting as the activation ligand. Using recombinant proteins, we aim to develop specific tools to control sexual development through the administration of IAG within the critical sexual differentiation time window. The biologically active rIAGs generated might facilitate commercially feasible solutions for the long sought techniques for sex-change induction and monosex population culture in crustaceans and shed new light on the physiological mode of action of IAG in crustaceans.


Assuntos
Androgênios/metabolismo , Palinuridae/genética , Receptores Proteína Tirosina Quinases/metabolismo , Testículo/crescimento & desenvolvimento , Animais , Masculino , Fosforilação , Diferenciação Sexual , Desenvolvimento Sexual
18.
Gen Comp Endocrinol ; 228: 111-127, 2016 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-26850661

RESUMO

Against a backdrop of food insecurity, the farming of decapod crustaceans is a rapidly expanding and globally significant source of food protein. Sagmariasus verreauxi spiny lobster, the subject of this study, are decapods of underdeveloped aquaculture potential. Crustacean neuropeptide G-protein coupled receptors (GPCRs) mediate endocrine pathways that are integral to animal fecundity, growth and survival. The potential use of novel biotechnologies to enhance GPCR-mediated physiology may assist in improving the health and productivity of farmed decapod populations. This study catalogues the GPCRs expressed in the early developmental stages, as well as adult tissues, with a view to illuminating key neuropeptide receptors. De novo assembled contiguous sequences generated from transcriptomic reads of metamorphic and post metamorphic S. verreauxi were filtered for seven transmembrane domains, and used as a reference for iterative re-mapping. Subsequent putative GPCR open reading frames (ORFs) were BLAST annotated, categorised, and compared to published orthologues based on phylogenetic analysis. A total of 85 GPCRs were digitally predicted, that represented each of the four arthropod subfamilies. They generally displayed low-level and non-differential metamorphic expression with few exceptions that we examined using RT-PCR and qPCR. Two putative CHH-like neuropeptide receptors were annotated. Three dimensional structural modelling suggests that these receptors exhibit a conserved extracellular ligand binding pocket, providing support to the notion that these receptors co-evolved with their ligands across Decapoda. This perhaps narrows the search for means to increase productivity of farmed decapod populations.


Assuntos
Simulação por Computador , Perfilação da Expressão Gênica , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Metamorfose Biológica/genética , Muda/genética , Palinuridae/genética , RNA/genética , Receptores Acoplados a Proteínas-G/genética , Animais , Regulação da Expressão Gênica , Palinuridae/classificação , Filogenia , Reação em Cadeia da Polimerase em Tempo Real
19.
Mitochondrial DNA A DNA Mapp Seq Anal ; 27(6): 4576-4577, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-26540371

RESUMO

We characterized the total mitochondrial genome of Australian spiny lobster, Panulirus cygnus (George, 1962), which is found along the western coast of Australia. Total mitochondrial genome length of P. cygnus was 15 724 bp, in which 13 proteins, 2 ribosomal RNAs, 22 transfer RNAs, and a putative control region were encoded. Nine and four protein-coding genes are encoded on the H-strand and on the L-strand, respectively. According to the phylogenetic analysis, P. cygnus was most closely related to Panulirus japonicus among the compared six species belonging to Palinuridae. Although overall gene organization was the same, the putative control region (between SrRNA gene and tRNAIlel) is least similar to one another among mitochondrial genomes from the compared six species belonging to Palinuridae.


Assuntos
Genoma Mitocondrial , Palinuridae/genética , Animais , Austrália , Códon de Iniciação , Fases de Leitura Aberta/genética , Palinuridae/classificação , Filogenia , RNA Ribossômico/química , RNA Ribossômico/genética , RNA de Transferência/química , RNA de Transferência/genética
20.
Mitochondrial DNA A DNA Mapp Seq Anal ; 27(4): 2700-9, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-26065848

RESUMO

Lobsters constitute low-volume high-value crustacean fishery resource along Indian coast. For the conservation and management of this declining resource, accurate identification of species and larvae is essential. The objectives of this work were to generate species-specific molecular signatures of 11 commercially important species of lobsters of families Palinuridae and Scyllaridae and to reconstruct a phylogeny to clarify the evolutionary relationships among genera and species included in this study. Partial sequences were generated for all the candidate species from sampling sites along the Indian coast using markers like Cytochrome oxidase I (COI), 16SrRNA, 12SrRNA, and 18SrRNA genes, and analyzed. The genetic identities of widely distributed Thenus species along the Indian coast to be Thenus unimaculatus and the sub-species of Panulirus homarus to be P. homarus homarus were confirmed. Phylogeny reconstruction using the individual gene and concatenated mtDNA data set were carried out. The overall results suggested independent monophyly of Scyllaridae and Stridentes of Palinuridae. The interspecific divergence was found to be highest for the 12SrRNA compared with other genes. Significant incongruence between mtDNA and nuclear 18SrRNA gene tree topologies was observed. The results hinted an earlier origin for Palinuridae compared with Scyllaridae. The DNA sequence data generated from this study will aid in the correct identification of lobster larvae and will find application in research related to larval transport and distribution.


Assuntos
Genoma Mitocondrial/genética , Palinuridae/genética , Animais , DNA Mitocondrial/genética , Palinuridae/classificação , Filogenia , RNA Ribossômico/genética
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