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1.
Sci Rep ; 14(1): 10353, 2024 05 06.
Artigo em Inglês | MEDLINE | ID: mdl-38710742

RESUMO

This study was conducted to verify the essentiality of dietary cholesterol for early juvenile slipper lobster, Thenus australiensis (initial weight 4.50 ± 0.72 g, mean ± SD, CV = 0.16), and to explore the potential for interactions between dietary cholesterol and phospholipid. An 8-week experiment was conducted using six experimental feeds containing three supplemental cholesterol concentrations (0, 0.2 and 0.4% dry matter) at two supplemental phospholipid concentrations (0% and 1.0% dry matter). Dietary cholesterol concentrations of ≥ 0.2% resulted in up to threefold greater weight gain compared to 0% dietary cholesterol, but without any significant main or interactive dietary phospholipid effect. An interaction was observed for lobster survival with lowest survival (46%) recorded for combined 0% cholesterol and 0% phospholipid compared to every other treatment (71-100%). However, all surviving lobsters at 0% dietary cholesterol, regardless of dietary phospholipid level, were in poor nutritional condition. Apparent feed intake (AFI) was significantly higher at dietary cholesterol ≥ 0.2% but was lower for each corresponding dietary cholesterol level at 1% dietary phospholipid. This implied that the feed conversion ratio was improved with supplemental phospholipid. In conclusion, this study confirms the essential nature of dietary cholesterol and that dietary phospholipid can provide additional benefits.


Assuntos
Ração Animal , Colesterol na Dieta , Palinuridae , Fosfolipídeos , Animais , Fosfolipídeos/metabolismo , Colesterol na Dieta/metabolismo , Palinuridae/metabolismo , Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal
2.
Int J Mol Sci ; 25(2)2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38256143

RESUMO

Cytochrome P450s (CYP450s) are a versatile superfamily of enzymes known to undergo rapid evolution. They have important roles across growth and development pathways in crustaceans, although it is difficult to characterise orthologs between species due to their sequence diversity. Conserved CYP450s enzymes in crustaceans are those associated with ecdysteroidogenesis: synthesising and breaking down the active moult hormone, 20-hydroxyecdysone. The complex life cycle of the ornate spiny lobster, Panulirus ornatus, relies on moulting in order to grow and develop. Many of these diverse life stages have been analysed to establish a comprehensive transcriptomic database for this species. The transcripts putatively encoding for CYP450s were mapped using transcriptomic analysis and identified across growth and development stages. With the aid of phylogeny, 28 transcripts of 42 putative P. ornatus CYP450s were annotated, including the well conserved Halloween genes, which are involved in ecdysteroidogenesis. Expression patterns across the life stages determined that only a subset of the CYP450s can be detected in each life stage or tissue. Four Shed transcripts show overlapping expression between metamorphosis and adult tissues, suggesting pleotropic functions of the multiple Shed orthologs within P. ornatus.


Assuntos
Palinuridae , Animais , Palinuridae/genética , Sistema Enzimático do Citocromo P-450/genética , Muda , Metamorfose Biológica/genética , Bases de Dados Factuais
3.
Sci Rep ; 13(1): 14378, 2023 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-37658120

RESUMO

The present study successfully combined a stoichiometric bioenergetic approach with an endpoint stochastic model to simultaneously determine specific dynamic action, metabolic substrate use and whole-body protein synthesis in juvenile slipper lobster Thenus australiensis. Juvenile lobsters were fasted for 48 h to investigate routine metabolism before receiving a single meal of formulated feed containing 1% 15N-labeled Spirulina. Postprandial oxygen consumption rate, dissolved inorganic carbon, and total nitrogen excretion returned to the pre-feeding level within 24 h. The rate of whole-body protein synthesis was 0.76 ± 0.15 mg CP g-1 day-1, with a significant reduction from 24 to 48 h post-feeding. The postprandial increase in whole-body protein synthesis accounted for 13-19% of total oxygen uptake. Protein was the primary energy substrate for 48 h fasted (45% oxygen consumption) and post-feeding lobster (44%), suggesting that dietary protein was not efficiently used for growth. The secondary energy substrate differed between carbohydrates in 48 h fasted and lipids in post-feeding lobsters. The present study recommends integrating protein synthesis into protein requirement experiments of marine ectotherms to acquire a more comprehensive picture of protein and energy metabolism and nutritional physiology crucial for formulating cost-effective aquafeeds.


Assuntos
Líquidos Corporais , Decápodes , Animais , Avaliação Nutricional , Metabolismo Energético , Carbono
4.
Sci Rep ; 13(1): 12409, 2023 07 31.
Artigo em Inglês | MEDLINE | ID: mdl-37524844

RESUMO

The tropical rock lobster, Panulirus ornatus, is a commercially important aquaculture species exhibiting complex social interactions in laboratory culture, including cannibalism of moulting conspecifics. Cannibalism of soft-shelled post-moult stage individuals is a major limitation during the juvenile stage of culture. Not limited to P. ornatus, cannibalism is widespread across farmed decapods, limiting stocking densities in crab, freshwater crayfish, and prawn species. To understand the mechanisms driving this behaviour and reduce its prevalence, we have investigated the role of chemoreception via the aesthetasc-bearing region of the lateral antennular flagellum, in the recognition of conspecific moulting cues. Differential expression analysis of several tissues in P. ornatus shows an upregulation of 70 ionotropic receptor isoforms, including co-receptors (IR25a and IR93a) and divergent receptors (IR4, IR7, and IR21a) in the aesthetasc-bearing region of the antennules. Deafferentation of the aesthetascs via deionised water exposure prevents juveniles from responding to conspecific moulting cues in a two-current choice flume, suggesting chemoreception, possibly olfaction, plays a role in identifying moulting juveniles. This is the first step in understanding the mechanisms via which cannibalism is triggered in juvenile P. ornatus culture. Further work in this area will help discover means to limit cannibalism in laboratory and commercial culture.


Assuntos
Palinuridae , Animais , Astacoidea , Flagelos , Muda , Palinuridae/fisiologia , Olfato
5.
Metallomics ; 15(6)2023 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-37327074

RESUMO

The ornate spiny rock lobster, Panulirus ornatus, is an attractive candidate for aquaculture. The larval stages of spiny lobsters, known as phyllosoma, are complex with many developmental stages. Very little is known about the inorganic element composition of phyllosoma. In this study, a novel method using synchrotron X-ray fluorescence microscopy (XFM) was applied to investigate the distributions of metals potassium (K), calcium (Ca), copper (Cu), zinc (Zn), the metalloid arsenic (As), and nonmetal bromine (Br) within individual phyllosoma at stages 3, 4, and 8 of their development. For the first time, 1 µm resolution synchrotron XFM images of whole phyllosoma as well as closer examinations of their eyes, mouths, setae, and tails were obtained. Elements accumulated in certain locations within phyllosoma, providing insight into their likely biological role for these organisms. This information may be useful for the application of dietary supplementation in the future to closed larval cycle lobster aquaculture operations.


Assuntos
Palinuridae , Animais , Raios X , Larva , Aquicultura , Microscopia de Fluorescência
6.
Gen Comp Endocrinol ; 332: 114183, 2023 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-36471526

RESUMO

Neuropeptides are commonly produced in the neural tissues yet can have effects on far-reaching targets, with varied biological responses. We describe here the neuropeptidome of the ornate spiny lobster, Panulirus ornatus, a species of emerging importance to closed-system aquaculture, with a focus on peptide hormones produced by the reproductive tissues. Transcripts for a precursor to one neuropeptide, adipokinetic hormone/corazonin-related peptide (ACP) were identified in high numbers in the sperm duct of adult spiny lobsters suggesting a role for ACP in the reproduction of this species. Neuropeptide production in the sperm duct may be linked with physiological control of spermatophore production in the male, or alternatively may function in signalling to the female. The enzymes which process nascent neuropeptide precursors into their mature, active forms have seldom been studied in decapods, and never before at the multi-tissue level. We have identified transcripts for multiple members of the proprotein convertase subtisilin/kexin family in the ornate spiny lobster, with some enzymes showing specificity to certain tissues. In addition, other enzyme transcripts involved with neuropeptide processing are identified along with their tissue and life stage expression patterns.


Assuntos
Neuropeptídeos , Palinuridae , Hormônios Peptídicos , Animais , Masculino , Feminino , Palinuridae/metabolismo , Hormônios Peptídicos/metabolismo , Sêmen/metabolismo , Neuropeptídeos/genética , Neuropeptídeos/metabolismo
7.
Sci Rep ; 12(1): 21474, 2022 12 12.
Artigo em Inglês | MEDLINE | ID: mdl-36509822

RESUMO

Characterising crustacean behaviour in response to conspecific chemical cues contributes to our evolving knowledge of the drivers of their social behaviour. There is particular interest in understanding the chemical and behavioural mechanisms contributing to cannibalism at ecdysis, as this behaviour substantially limits culture productivity of several commercially important crustaceans. Before investigating the role of chemoreception in cannibalism of moulting crustaceans, we must investigate its role in detecting moulting conspecifics. Here we use a two-current choice flume to observe juvenile tropical rock lobster (Panulirus ornatus) behavioural response to conspecific moulting cues and identifying attracted and avoidant behaviours correlating to moult stage and social relationship. Observed cue preferences show inter-moult juveniles are attracted to the moulting cues of lobsters to which they are socially naïve. In contrast, post-moult and inter-moult juveniles avoid the moulting cues of individuals whom they are socially familiar with. Average speed and total distance travelled by lobsters increases in response to conspecific moulting cues. This study demonstrates the suitability of a two-current choice flume for behavioural assays in P. ornatus and characterises clear behavioural patterns in juveniles exposed to conspecific moulting cues. This provides important framework for understanding the role of chemical communication in eliciting cannibalism.


Assuntos
Muda , Palinuridae , Humanos , Animais , Palinuridae/fisiologia , Sinais (Psicologia)
8.
Int J Mol Sci ; 23(19)2022 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-36233053

RESUMO

RNA interference (RNAi) has been widely utilised in many invertebrate models since its discovery, and in a majority of instances presents as a highly efficient and potent gene silencing mechanism. This is emphasized in crustaceans with almost all taxa having the capacity to trigger effective silencing, with a notable exception in the spiny lobsters where repeated attempts at dsRNA induced RNAi have demonstrated extremely ineffective gene knockdown. A comparison of the core RNAi machinery in transcriptomic data from spiny lobsters (Panulirus ornatus) and the closely related slipper lobsters (Thenus australiensis, where silencing is highly effective) revealed that both lobsters possess all proteins involved in the small interfering and microRNA pathways, and that there was little difference at both the sequence and domain architecture level. Comparing the expression of these genes however demonstrated that T. australiensis had significantly higher expression in the transcripts encoding proteins which directly interact with dsRNA when compared to P. ornatus, validated via qPCR. These results suggest that low expression of the core RNAi genes may be hindering the silencing response in P. ornatus, and suggest that it may be critical to enhance the expression of these genes to induce efficient silencing in spiny lobsters.


Assuntos
Decápodes , MicroRNAs , Palinuridae , Animais , Palinuridae/genética , Interferência de RNA , Transcriptoma
9.
Animals (Basel) ; 12(17)2022 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-36077960

RESUMO

Spiny lobsters have a range of complex chemical communication pathways that contribute to feeding behaviour. Feed intake is modulated by feed availability and feed characteristics, such as attractiveness and palatability, with behavioural factors, such as social competition and circadian rhythm, providing an extra layer of complexity. In this study, we investigated the effect of feed frequency on survival and growth of early-stage (instar 2-6) juvenile Palunirus ornatus. In addition, we investigated the interactive effect of feed frequency and circadian rhythm on lobster feed response. Lobsters were fed a set ration at a frequency of either one, two, four, eight, sixteen or thirty-two times per day over 49 days. The effect of feed frequency on growth and survival was determined. Circadian feeding activity under these feeding treatments was assessed by time-lapse photography. Increased feed frequency from one to sixteen feeds daily improved growth by increasing apparent feed intake (AFI) and feed attraction, as confirmed by the increased presence of lobsters in the feeding area. The rapid leaching of feed attractant, particularly free amino acid, suggests a beneficial effect of multiple feeding frequencies on feed intake and growth. However, more than sixteen feeds per day resulted in decreased feed intake and a subsequent reduction in growth. The decrease in feed intake is thought to be associated with saturation of the culture environment with attractants, resulting in a reduced behavioural response to feed supplies. This may indicate the need for depletion of attractants to retrigger a feeding response. As lobsters were grown communally, faster growth at sixteen rations per day was also coupled with increased cannibalism, likely driven by increased vulnerability with the occurrence of more frequent ecdysis events. Whereas circadian rhythm indicated more activity at night, an interaction between daytime activity and feed frequency was not observed.

10.
Artigo em Inglês | MEDLINE | ID: mdl-34822975

RESUMO

Apparent digestibility and gastrointestinal evacuation rate were measured to assess the potential of five commercially available protein sources for their inclusion in feeds for juvenile slipper lobster, Thenus australiensis. Protein sources tested were fishmeal, krill meal, lupin meal, soybean meal and squid by-product meal. Apparent digestibility of crude protein ranged from 79.6% to 95.3%, with fishmeal protein significantly less digestible than lupin meal, squid by-product meal and soybean meal. Gastrointestinal evacuation rate was estimated from marker replacement, where yttrium oxide replaced ytterbium oxide. Faeces were collected every 3 h for 48 h, and a kinetic model was used to calculate the rate and time for the second marker to replace the first marker. Gastrointestinal evacuation (≥ 95%) was completed between 4 and 6 h with no significant differences among protein sources. Faeces consisted of both markers in equal parts 2.7 to 5.0 h after the feed switch, with lupin meal reaching the midpoint significantly faster than squid by-product meal and reference feed. The present study is the first in crustaceans to examine the relationship between apparent digestibility and gastrointestinal evacuation, showing more digestible protein sources had slower evacuation rates. The combined approach provides deeper insight into crustaceans' digestive physiology and helps understand their ability to digest specific ingredients. Further research is recommended to understand protein requirements in a broader context to verify highly digestible protein sources meet all nutritional requirements.


Assuntos
Ração Animal , Nephropidae , Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal , Animais , Dieta , Digestão/fisiologia , Fezes , Trato Gastrointestinal , Glycine max/metabolismo
11.
Microbiology (Reading) ; 167(11)2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34846286

RESUMO

Bdellovibrio and like organisms (BALOs) are Gram-negative obligate predators of other bacteria in a range of environments. The recent discovery of BALOs in the circulatory system of cultured spiny lobster P. ornatus warrants more investigation. We used a combination of co-culture agar and broth assays and transmission electron microscopy to show a Halobacteriovorax sp. strain Hbv preyed upon the model prey bacterium Vibrio sp. strain Vib. The haemolymph microbiome of juvenile P. ornatus was characterised following injection of phosphate buffered saline (control) or prey and/or predator bacteria for 3 d. The predator Hbv had no effect on survival compared to the control after 3 d. However, when compared to the prey only treatment group, lobsters injected with both prey and predator showed significantly lower abundance of genus Vibrio in the haemolymph bacterial community composition. This study indicates that predatory bacteria are not pathogenic and may assist in controlling microbial population growth in the haemolymph of lobsters.


Assuntos
Bdellovibrio , Microbiota , Palinuridae , Animais , Bactérias , Hemolinfa , Palinuridae/microbiologia
13.
Sci Rep ; 11(1): 11814, 2021 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-34083691

RESUMO

This is the first study in an aquatic ectotherm to combine a stoichiometric bioenergetic approach with an endpoint stochastic model to explore dietary macronutrient content. The combination of measuring respiratory gas (O2 and CO2) exchange, nitrogenous (ammonia and urea) excretion, specific dynamic action (SDA), metabolic energy substrate use, and whole-body protein synthesis in spiny lobster, Sagmariasus verreauxi, was examined in relation to dietary protein. Three isoenergetic feeds were formulated with varying crude protein: 40%, 50% and 60%, corresponding to CP40, CP50 and CP60 treatments, respectively. Total CO2 and ammonia excretion, SDA magnitude and coefficient, and protein synthesis in the CP60 treatment were higher compared to the CP40 treatment. These differences demonstrate dietary protein influences post-prandial energy metabolism. Metabolic use of each major energy substrate varied at different post-prandial times, indicating suitable amounts of high-quality protein with major non-protein energy-yielding nutrients, lipid and carbohydrate, are critical for lobsters. The average contribution of protein oxidation was lowest in the CP50 treatment, suggesting mechanisms underlying the most efficient retention of dietary protein and suitable dietary inclusion. This study advances understanding of how deficient and surplus dietary protein affects energy metabolism and provides approaches for fine-scale feed evaluation to support sustainable aquaculture.


Assuntos
Fenômenos Fisiológicos da Nutrição Animal , Proteínas Alimentares/metabolismo , Metabolismo Energético , Palinuridae/metabolismo , Biossíntese de Proteínas , Fatores Etários , Amônia/metabolismo , Animais , Carboidratos da Dieta/metabolismo , Nitrogênio/metabolismo
14.
Heliyon ; 7(4): e06885, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33997410

RESUMO

A direct, robust, accurate and highly sensitive method for oxyhalide species in natural waters, including seawater, using suppressed ion chromatography coupled with mass spectrometry (IC-MS) is described. The method utilised a high capacity, high efficiency anion-exchange column (Dionex IonPac AS11-HC, 4 mm, 2 × 250 mm), with the separation achieved using an electrolytically generated potassium hydroxide gradient, delivered at 0.380 mL min-1. Applying the method, detection limits for iodate, bromate, and chlorate in seawater after direct sample injection (20 µL injection volume, samples diluted 10-fold), were 11, 30 and 13 ng L-1 (ppt), respectively. Standard addition calibrations to ozonated seawater samples were linear, in all cases R2 > 0.999 (n = 10), with intra-day repeatability of 3.7, 11.2 and 1.8 % RSD (n = 10) for a low-level standard mixture (0.30 µg L-1 of iodate, 0.15 µg L-1 of bromate, and 1.50 µg L-1 of chlorate). The method was applied to the analysis of seawater samples taken pre- and post-disinfection points within a recirculating aquacultural system. Iodate, bromate and chlorate were detected as the main oxyanionic disinfection by-products, demonstrating the practical utility of the new method as a valuable tool for monitoring changes to seawater composition following disinfection treatments.

15.
Nat Commun ; 12(1): 2395, 2021 04 22.
Artigo em Inglês | MEDLINE | ID: mdl-33888695

RESUMO

The infraorder Brachyura (true or short-tailed crabs) represents a successful group of marine invertebrates yet with limited genomic resources. Here we report a chromosome-anchored reference genome and transcriptomes of the Chinese mitten crab Eriocheir sinensis, a catadromous crab and invasive species with wide environmental tolerance, strong osmoregulatory capacity and high fertility. We show the expansion of specific gene families in the crab, including F-ATPase, which enhances our knowledge on the adaptive plasticity of this successful invasive species. Our analysis of spatio-temporal transcriptomes and the genome of E. sinensis and other decapods shows that brachyurization development is associated with down-regulation of Hox genes at the megalopa stage when tail shortening occurs. A better understanding of the molecular mechanism regulating sexual development is achieved by integrated analysis of multiple omics. These genomic resources significantly expand the gene repertoire of Brachyura, and provide insights into the biology of this group, and Crustacea in general.


Assuntos
Adaptação Fisiológica/genética , Braquiúros/fisiologia , Regulação da Expressão Gênica no Desenvolvimento , Genoma/genética , Animais , Aquicultura , Mapeamento Cromossômico , Feminino , Fertilidade/genética , Perfilação da Expressão Gênica , Genes Homeobox/genética , Genômica , Espécies Introduzidas , Estágios do Ciclo de Vida/genética , Masculino , Família Multigênica/genética , Osmorregulação/genética , Desenvolvimento Sexual/genética , Análise Espaço-Temporal , Sequenciamento Completo do Genoma
16.
Front Microbiol ; 11: 573588, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33162955

RESUMO

Shell (cuticular) disease manifests in various forms and affects many crustaceans, including lobsters. Outbreaks of white leg disease (WLD) with distinct signs of pereiopod tissue whitening and death have been observed in cultured larvae (phyllosomas) of ornate spiny lobster Panulirus ornatus, eastern rock lobster Sagmariasus verreauxi, and slipper lobster Thenus australiensis. This study aimed to characterise and identify the causative agent of WLD through morphological and molecular (16S rRNA gene and whole genome sequencing) analysis, experimental infection of damaged/undamaged P. ornatus and T. australiensis phyllosomas, and bacterial community analysis (16S rRNA gene amplicon sequencing) of P. ornatus phyllosomas presenting with WLD during an outbreak. Bacterial communities of WLD-affected pereiopods showed low bacterial diversity and dominant abundance of Aquimarina spp. compared to healthy pereiopods, which were more diverse and enriched with Sulfitobacter spp. 16S rRNA gene Sanger sequencing of cultures from disease outbreaks identified the dominant bacterial isolate (TRL1) as a Gram-negative, long non-flagellated rod with 100% sequence identity to Aquimarina hainanensis. Aquimarina sp. TRL1 was demonstrated through comparative genome analysis (99.99% OrthoANIu) as the bacterium reisolated from experimentally infected phyllosomas presenting with typical signs of WLD. Pereiopod damage was a major predisposing factor to WLD. Histopathological examination of WLD-affected pereiopods showed masses of internalised bacteria and loss of structural integrity, suggesting that Aquimarina sp. TRL1 could enter the circulatory system and cause death by septicaemia. Aquimarina sp. TRL1 appears to have important genomic traits (e.g., tissue-degrading enzymes, gliding motility, and aggregate-promoting factors) implicated in the pathogenicity of this bacterium. We have shown that Aquimarina sp. TRL1 is the aetiological agent of WLD in cultured Palinurid and Scyllarid phyllosomas and that damaged pereiopods are a predisposing factor to WLD.

17.
Genes (Basel) ; 11(10)2020 09 29.
Artigo em Inglês | MEDLINE | ID: mdl-33003631

RESUMO

Sexual development involves the successive and overlapping processes of sex determination, sexual differentiation, and ultimately sexual maturation, enabling animals to reproduce. This provides a mechanism for enriched genetic variation which enables populations to withstand ever-changing environments, selecting for adapted individuals and driving speciation. The molecular mechanisms of sexual development display a bewildering diversity, even in closely related taxa. Many sex determination mechanisms across animals include the key family of "doublesex- and male abnormal3-related transcription factors" (Dmrts). In a few exceptional species, a single Dmrt residing on a sex chromosome acts as the master sex regulator. In this study, we provide compelling evidence for this model of sex determination in the ornate spiny lobster Panulius ornatus, concurrent with recent reports in the eastern spiny lobster Sagmariasus verreauxi. Using a multi-tissue transcriptomic database established for P. ornatus, we screened for the key factors associated with sexual development (by homology search and using previous knowledge of these factors from related species), providing an in-depth understanding of sexual development in decapods. Further research has the potential to close significant gaps in our understanding of reproductive development in this ecologically and commercially significant order.


Assuntos
Proteínas de Artrópodes/genética , Regulação da Expressão Gênica no Desenvolvimento , Palinuridae/genética , Desenvolvimento Sexual , Transcriptoma , Animais , Perfilação da Expressão Gênica , Palinuridae/crescimento & desenvolvimento
18.
Int J Mol Sci ; 21(18)2020 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-32971953

RESUMO

RNA interference (RNAi) has become a widely utilized method for studying gene function, yet despite this many of the mechanisms surrounding RNAi remain elusive. The core RNAi machinery is relatively well understood, however many of the systemic mechanisms, particularly double-stranded RNA (dsRNA) transport, are not. Here, we demonstrate that dsRNA binding proteins in the serum contribute to systemic RNAi and may be the limiting factor in RNAi capacity for species such as spiny lobsters, where gene silencing is not functional. Incubating sera from a variety of species across phyla with dsRNA led to a gel mobility shift in species in which systemic RNAi has been observed, with this response being absent in species in which systemic RNAi has never been observed. Proteomic analysis suggested lipoproteins may be responsible for this phenomenon and may transport dsRNA to spread the RNAi signal systemically. Following this, we identified the same gel shift in the slipper lobster Thenus australiensis and subsequently silenced the insulin androgenic gland hormone, marking the first time RNAi has been performed in any lobster species. These results pave the way for inducing RNAi in spiny lobsters and for a better understanding of the mechanisms of systemic RNAi in Crustacea, as well as across phyla.


Assuntos
Proteínas de Artrópodes , Palinuridae , Interferência de RNA , RNA de Cadeia Dupla , Proteínas de Ligação a RNA , Animais , Proteínas de Artrópodes/genética , Proteínas de Artrópodes/metabolismo , Humanos , Palinuridae/genética , Palinuridae/metabolismo , RNA de Cadeia Dupla/genética , RNA de Cadeia Dupla/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo
19.
Artigo em Inglês | MEDLINE | ID: mdl-32916299

RESUMO

The moult cycle is arguably the most critical aspect of crustacean biology and is associated with dramatic changes in behaviour, physiology and condition. Here we describe the first detailed investigation of the combined changes in morphology, physiological status and nutritional condition over the moult cycle of juvenile T. australiensis. Haemolymph refractive index (measured as Brix) was evaluated as a non-destructive method for predicting physiological status and nutritional condition. Post-moult, inter-moult and pre-moult stages were identifiable by microscopic examination of the pleopod distal tips, though differentiation of the pre-moult substages was not possible using this technique. Monitoring of ecdysial suture lines on the exoskeleton gill chambers was found to be highly useful for visually determining progression through the pre-moult stage and predicting the timing of ecdysis. A classical pattern of inter-moult growth was observed where size and wet weight remained relatively uniform over the moult cycle while highly significant changes in whole-body composition were simultaneously observed over time. Growth was most evident by changes in dry weight and dry matter content which more than doubled by the onset of pre-moult. Changes in dry matter content were generally mirrored by Brix and whole-body crude protein, total lipid and gross energy content. Brix strongly correlated with dry matter content and significant correlations were also found for all other primary measures of nutritional condition. Typical moult-related changes were also found for circulating ecdysteroids. This study clearly demonstrates pronounced cyclical changes in physiology and condition of juvenile T. australiensis over a typical moult cycle. The significant correlations between haemolymph and whole-body composition validates Brix as a practical and non-destructive method to objectively assess physiological status, nutritional condition and quality in T. australiensis and further demonstrates its potential for individual crustacean assessment in experimental research and practical commercial applications.


Assuntos
Decápodes/crescimento & desenvolvimento , Decápodes/metabolismo , Muda , Estado Nutricional , Animais , Técnicas de Cultura , Metabolismo Energético
20.
BMC Genomics ; 21(1): 637, 2020 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-32928113

RESUMO

Transcriptome sequencing has opened the field of genomics to a wide variety of researchers, owing to its efficiency, applicability across species and ability to quantify gene expression. The resulting datasets are a rich source of information that can be mined for many years into the future, with each dataset providing a unique angle on a specific context in biology. Maintaining accessibility to this accumulation of data presents quite a challenge for researchers.The primary focus of conventional genomics databases is the storage, navigation and interpretation of sequence data, which is typically classified down to the level of a species or individual. The addition of expression data adds a new dimension to this paradigm - the sampling context. Does gene expression describe different tissues, a temporal distribution or an experimental treatment? These data not only describe an individual, but the biological context surrounding that individual. The structure and utility of a transcriptome database must therefore reflect these attributes. We present an online database which has been designed to maximise the accessibility of crustacean transcriptome data by providing intuitive navigation within and between datasets and instant visualization of gene expression and protein structure.The site is accessible at https://crustybase.org and currently holds 10 datasets from a range of crustacean species. It also allows for upload of novel transcriptome datasets through a simple web interface, allowing the research community to contribute their own data to a pool of shared knowledge.


Assuntos
Crustáceos/genética , Bases de Dados Genéticas , Transcriptoma , Animais , Crustáceos/metabolismo , Software
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