scholarly journals Venomics Reveals Venom Complexity of the Piscivorous Cone Snail, Conus tulipa

Marine Drugs ◽  
2019 ◽  
Vol 17 (1) ◽  
pp. 71 ◽  
Author(s):  
Mriga Dutt ◽  
Sébastien Dutertre ◽  
Ai-Hua Jin ◽  
Vincent Lavergne ◽  
Paul Alewood ◽  
...  
Keyword(s):  
Ion Channel ◽  
Transcriptomic Analysis ◽  
Nmda Antagonists ◽  
Cone Snail ◽  
Expression Levels ◽  
Hunting Strategy

The piscivorous cone snail Conus tulipa has evolved a net-hunting strategy, akin to the deadly Conus geographus, and is considered the second most dangerous cone snail to humans. Here, we present the first venomics study of C. tulipa venom using integrated transcriptomic and proteomic approaches. Parallel transcriptomic analysis of two C. tulipa specimens revealed striking differences in conopeptide expression levels (2.5-fold) between individuals, identifying 522 and 328 conotoxin precursors from 18 known gene superfamilies. Despite broad overlap at the superfamily level, only 86 precursors (11%) were common to both specimens. Conantokins (NMDA antagonists) from the superfamily B1 dominated the transcriptome and proteome of C. tulipa venom, along with superfamilies B2, A, O1, O3, con-ikot-ikot and conopressins, plus novel putative conotoxins precursors T1.3, T6.2, T6.3, T6.4 and T8.1. Thus, C. tulipa venom comprised both paralytic (putative ion channel modulating α-, ω-, μ-, δ-) and non-paralytic (conantokins, con-ikot-ikots, conopressins) conotoxins. This venomic study confirms the potential for non-paralytic conotoxins to contribute to the net-hunting strategy of C. tulipa.

scholarly journals Meta-Transcriptomic Analysis of RNAseq Data Reveals Pacu and Loach Fish with Unusually High Levels of Myoglobin Expression in Skeletal Muscles

Animals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1130
Author(s):  
Rui-Yi Chen ◽  
Bui Thi Ngoc Hieu ◽  
Gilbert Audira ◽  
Bao Lou ◽  
Ming-Der Lin ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Protein Expression ◽  
Fish Species ◽  
Binding Proteins ◽  
Binding Protein ◽  
Transcriptomic Analysis ◽  
Oxygen Binding ◽  
Putative Gene ◽  
Expression Levels ◽  
Rnaseq Data

Oxygen-binding proteins, such as myoglobin, hemoglobin, neuroglobin, and cytoglobin, play a role in oxygen binding and delivery to tissues. In icefish, the loss of myoglobin and hemoglobin genes has been reported to be an adaptive evolution event. This interesting finding prompted us to exam oxygen-binding protein expression in diverse fish species. Taking advantage of substantial RNAseq data deposited in the NCBI (National Center for Biotechnology Information) database, we adopted a meta-transcriptomic approach to explore and compare four oxygen-binding protein gene expression levels in the skeletal muscle of 25 diverse fish species for the first time. RNAseq data were downloaded from the NCBI Sequence Read Archive (SRA) database, and de novo assembly was performed to generate transcript contigs. The genes encoding oxygen-binding proteins were then identified by the BLAST search, and the relative expression level of oxygen-binding protein genes was normalized by the RPKM (Reads per Kilobase Million) method. By performing expression profiling, hierarchy clustering, and principal component analysis, pacu and loach fish were noticed by their high myoglobin expression levels in skeletal muscle tissues among 25 diverse fish species. In conclusion, we demonstrated that meta-transcriptomic analysis of RNAseq data is an informative approach to compare the oxygen-binding protein expression and putative gene expansion event in fish.

scholarly journals Proteomic and Transcriptomic Analysis of Aspergillus fumigatus on Exposure to Amphotericin B

2008 ◽  
Vol 52 (12) ◽  
pp. 4220-4227 ◽  
Author(s):  
Poonam Gautam ◽  
Jata Shankar ◽  
Taruna Madan ◽  
Ravi Sirdeshmukh ◽  
Curam Sreenivasacharlu Sundaram ◽  
...  
Keyword(s):  
Aspergillus Fumigatus ◽  
Differential Expression ◽  
Amphotericin B ◽  
Stress Proteins ◽  
Fungal Infections ◽  
Antifungal Drug ◽  
Transcriptomic Analysis ◽  
Differentially Expressed ◽  
Specific Response ◽  
Expression Levels

ABSTRACT Amphotericin B (AMB) is the most widely used polyene antifungal drug for the treatment of systemic fungal infections, including invasive aspergillosis. It has been our aim to understand the molecular targets of AMB in Aspergillus fumigatus by genomic and proteomic approaches. In transcriptomic analysis, a total of 295 genes were found to be differentially expressed (165 upregulated and 130 downregulated), including many involving the ergosterol pathway, cell stress proteins, cell wall proteins, transport proteins, and hypothetical proteins. Proteomic profiles of A. fumigatus alone or A. fumigatus treated with AMB showed differential expression levels for 85 proteins (76 upregulated and 9 downregulated). Forty-eight of them were identified with high confidence and belonged to the above-mentioned categories. Differential expression levels for Rho-GDP dissociation inhibitor (Rho-GDI), secretory-pathway GDI, clathrin, Sec 31 (a subunit of the exocyst complex), and RAB GTPase Ypt51 in response to an antifungal drug are reported here for the first time and may represent a specific response of A. fumigatus to AMB. The expression of some of these genes was validated by real-time reverse transcription-PCR. The AMB responsive genes/proteins observed to be differentially expressed in A. fumigatus may be further explored for novel drug development.

scholarly journals Characterisation of δ-Conotoxin TxVIA as a Mammalian T-Type Calcium Channel Modulator

Marine Drugs ◽  
2020 ◽  
Vol 18 (7) ◽  
pp. 343
Author(s):  
Dan Wang ◽  
S.W.A. Himaya ◽  
Jean Giacomotto ◽  
Md. Mahadhi Hasan ◽  
Fernanda C. Cardoso ◽  
...  
Keyword(s):  
Amino Acid ◽  
Ion Channel ◽  
Calcium Channel ◽  
Binding Sites ◽  
Molluscan Neurons ◽  
Cone Snail ◽  
Voltage Gated ◽  
Channel Inactivation ◽  
High Concentrations ◽  
Channel Modulator

The 27-amino acid (aa)-long δ-conotoxin TxVIA, originally isolated from the mollusc-hunting cone snail Conus textile, slows voltage-gated sodium (NaV) channel inactivation in molluscan neurons, but its mammalian ion channel targets remain undetermined. In this study, we confirmed that TxVIA was inactive on mammalian NaV1.2 and NaV1.7 even at high concentrations (10 µM). Given the fact that invertebrate NaV channel and T-type calcium channels (CaV3.x) are evolutionarily related, we examined the possibility that TxVIA may act on CaV3.x. Electrophysiological characterisation of the native TxVIA on CaV3.1, 3.2 and 3.3 revealed that TxVIA preferentially inhibits CaV3.2 current (IC50 = 0.24 μM) and enhances CaV3.1 current at higher concentrations. In fish bioassays TxVIA showed little effect on zebrafish behaviours when injected intramuscular at 250 ng/100 mg fish. The binding sites for TxVIA at NaV1.7 and CaV3.1 revealed that their channel binding sites contained a common epitope.

scholarly journals Comparative transcriptomic analysis of maize ear heterosis during the inflorescence meristem differentiation stage

2021 ◽  
Author(s):  
Xia Shi ◽  
Weihua li ◽  
Zhanyong Guo ◽  
Mingbo Wu ◽  
Xiangge Zhang ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Transcriptomic Analysis ◽  
Inflorescence Meristem ◽  
Specific Expression ◽  
Ear Development ◽  
Expression Levels ◽  
Transcriptional Variation ◽  
Heterotic Locus ◽  
Segment Substitution ◽  
Maize Ear

AbstractHeterosis is widely used in many crops; however, its genetic mechanisms are only partly understood. Here, we sampled inflorescence meristem (IM) ears from the single-segment substitution maize (Zea mays) line lx9801hlEW2b, containing a heterotic locus hlEW2b associated with ear width, the receptor parent lx9801, the test parent Zheng58, and their corresponding hybrids. After transcriptomic analysis, 1638 genes were identified in at least one hybrid with nonadditively expressed patterns and different expression levels between the two hybrids. In particular, 2263 (12.89%) and 2352 (14.65%) genes showed allele-specific expression (ASE) in Zheng58 × lx9801 and Zheng58 × lx9801hlEW2b, respectively. A functional analysis showed that these genes were enriched in development-related processes and biosynthesis and catabolism processes, which are potentially associated with heterosis. Additionally, nonadditive expression and ASE may fine-tune the expression levels of crucial genes (such as WUS and KNOX that control IM development) controlling auxin metabolism and ear development to optimal states, and transcriptional variation may play important roles in maize ear heterosis. The results provide new information that increases our understanding of the relationship between transcriptional variation and heterosis formation during maize ear development, which may be helpful in clarifying the genetic and molecular mechanisms of heterosis.

scholarly journals Small-molecule mimicry hunting strategy in the imperial cone snail, Conus imperialis

2021 ◽  
Vol 7 (11) ◽  
pp. eabf2704
Author(s):  
Joshua P. Torres ◽  
Zhenjian Lin ◽  
Maren Watkins ◽  
Paula Flórez Salcedo ◽  
Robert P. Baskin ◽  
...  
Keyword(s):  
Small Molecules ◽  
Bioactive Peptides ◽  
Cone Snail ◽  
Fake News ◽  
Specialized Metabolites ◽  
Hunting Strategies ◽  
Venomous Animals ◽  
Platynereis Dumerilii ◽  
Species Specific ◽  
Hunting Strategy

Venomous animals hunt using bioactive peptides, but relatively little is known about venom small molecules and the resulting complex hunting behaviors. Here, we explored the specialized metabolites from the venom of the worm-hunting cone snail, Conus imperialis. Using the model polychaete worm Platynereis dumerilii, we demonstrate that C. imperialis venom contains small molecules that mimic natural polychaete mating pheromones, evoking the mating phenotype in worms. The specialized metabolites from different cone snails are species-specific and structurally diverse, suggesting that the cones may adopt many different prey-hunting strategies enabled by small molecules. Predators sometimes attract prey using the prey’s own pheromones, in a strategy known as aggressive mimicry. Instead, C. imperialis uses metabolically stable mimics of those pheromones, indicating that, in biological mimicry, even the molecules themselves may be disguised, providing a twist on fake news in chemical ecology.

scholarly journals A Transcriptomic Survey of Ion Channel-Based Conotoxins in the Chinese Tubular Cone Snail (Conus betulinus)

Marine Drugs ◽  
2017 ◽  
Vol 15 (7) ◽  
pp. 228 ◽  
Author(s):  
Yu Huang ◽  
Chao Peng ◽  
Yunhai Yi ◽  
Bingmiao Gao ◽  
Qiong Shi
Keyword(s):  
Ion Channel ◽  
Cone Snail ◽  
Conus Betulinus
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