Biology subjects

Chen, X.

Publications and source records attributed to Chen, X..

1,619 records · Page 90Linked to original sources

bioRxiv2017

Harnessing the Cross-talk between Tumor Cells and Tumor-associated Macrophages with a Nano-drug for modulation of Glioblastoma Immune Microenvironment

Glioblastoma (GBM) is the most frequent and malignant brain tumor with a high mortality rate. The presence of a large population of macrophages (M{varphi}) in the tumor microenvironment is a prominent feature of GBM and these so-called tumor-associated M{varphi} (TAM) closely interact with the GBM cells to promote the survival, progression and therapy resistance of the GBM. Various therapeutic strategies have been devised either targeting the GBM cells or the TAM but few have addressed the cross-talks between the two cell populations. The present study was carried out to explore the possibility of exploiting the cross-talks between the GBM cells (GC) and TAM for modulation of the GBM microenvironment through using Nano-DOX, a drug composite based on nanodiamonds bearing doxorubicin. In the in vitro work on human cell models, Nano-DOX-loaded TAM were first shown to be viable and able to infiltrate three-dimensional GC spheroids and release cargo drug therein. GC were then demonstrated to encourage Nano-DOX-loaded TAM to unload Nano-DOX back into GC which consequently emitted damage-associated molecular patterns (DAMPs) that are powerful immunostimulatory agents as well as indicators of cell damage. Nano-DOX was next proven to be a more potent inducer of GC DAMPs emission than doxorubicin. As a result, Nano-DOX-damaged GC exhibited an enhanced ability to attract both TAM and Nano-DOX-loaded TAM. Most remarkably, Nano-DOX-damaged GC reprogrammed the TAM from a pro-GBM phenotype to an anti-GBM phenotype that suppressed GC growth. Finally, the in vivo relevance of the in vitro findings was tested in animal study. Mice bearing orthotopic human GBM xenografts were intravenously injected with Nano-DOX-loaded mouse TAM which were found releasing drug in the GBM xenografts 24 h after injection. GC damage was evidenced by the induction of DAMPs emission within the xenografts and a shift of TAM phenotype was detected as well. Taken together, our results demonstrate a novel way with therapeutic potential to harness the cross-talk between GBM cells and TAM for modulation of the tumor immune microenvironment.\n\nAbbreviationsATP, adenosine triphosphate; BBB, blood-brain barrier; BCA, bicinchoninic acid; BMDM, bone marrow derived macrophages; CD, cluster of differentiation; CFSE, 5(6)-carboxyfluorescein diacetate, succinimidyl ester; CM, conditioned culture medium; CNS, central nervous system; CRT, calreticulin; DAMPs, damage-associated molecular patterns; DAB, diaminobenzidine; DOX, doxorubicin; ECL, enhanced chemiluminescence; ELISA, enzyme-linked immunosorbent assay; HMGB1, high mobility group protein B1; HSP90, heat shock protein 90; FACS, flow cytometry; GBM, glioblastoma; Guanylate Binding Protein 5 (GBP5); GC, glioblastoma cells; IHC, immunohistochemical; IL, interleukin; M{varphi}, macrophages; mBMDM, mouse BMDM; mBMDM2, Type-2 mBMDM; M1, Type-1 Mo; M2, Type-2 Mo; Nano-DOX, ND-PG-RGD-DOX; ND, nanodiamonds; Nano-DOX-mBMDM, Nano-DOX-loaded mouse BMDM; NGCM, Nano-DOX-treated-GC-conditioned medium; PBS, phosphate buffered saline; PG, polyglycerol; PMA, phorbol 12-myristate 13-acetate; PVDF, polyvinylidene fluoride; RGD, tripeptide of L-arginine, glycine and L-aspartic acid; RM, regular culture medium; SD, standard deviation; TAM, tumor-associated M{varphi}; TBST, Tris Buffered Saline with Tween(R) 20.\n\nGraphic abstract\n\nO_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=153 SRC=\"FIGDIR/small/170282_ufig1.gif\" ALT=\"Figure 1\">\nView larger version (111K):\norg.highwire.dtl.DTLVardef@180aea2org.highwire.dtl.DTLVardef@14922f7org.highwire.dtl.DTLVardef@96a696org.highwire.dtl.DTLVardef@92f050_HPS_FORMAT_FIGEXP M_FIG C_FIG

pharmacology and toxicology↗

bioRxiv2017

Biomass increase under zinc deficiency caused by delay of early flowering in Arabidopsis

Plants generally produce more biomass when all nutrients are available in sufficient amounts. In addition to environmental constraints, genetic and developmental factors, such as the transition from vegetative to reproductive growth, restrict maximal yield. Here we report the peculiar observation that a subset of early flowering Arabidopsis thaliana accessions produced larger shoot rosette diameters when grown in zinc (Zn)-deficient conditions, compared with Zn-sufficient conditions. This was associated with early flowering that restricted the leaf length under Zn sufficiency. Zinc deficiency repressed FLOWERING LOCUS T (FT) expression, a major regulator of flowering. Repression or loss of FT increased the rosette diameter by a delay of the transition to flowering, a longer phase of leaf proliferation and increased leaf number. The transition to flowering reduced, but not terminated, the proliferation of established leaves. The size of individual leaf mesophyll cells was not affected by Zn deficiency or loss of FT, indicating that the larger rosette diameter was caused by maintained proliferation of vegetative tissue. As a consequence, early flowering accessions under Zn deficiency grew larger rosette diameters due to a delay of flowering, which explains the unusual increase of vegetative biomass under nutrient deficiency.\n\nHighlightAn increase in biomass of some Arabidopsis accessions under Zn-deficiency is caused by retardation of flowering, prolonging vegetative growth.\n\nAbbreviations

plant biology↗

bioRxiv2017

Ribosome profiling reveals post-translational signaling mechanisms drive the retrograde enhancement of presynaptic efficacy

Presynaptic efficacy can be modulated by retrograde control mechanisms, but the nature of these complex signaling systems remain obscure. We have developed and optimized a tissue specific ribosome profiling approach in Drosophila. We first demonstrate the ability of this technology to define genome-wide translational regulations. We then leverage this technology to test the relative contributions of transcriptional, translational, and post-translational mechanisms in the postsynaptic muscle that orchestrate the retrograde control of presynaptic function. Surprisingly, we find no changes in transcription or translation are necessary to enable retrograde homeostatic signaling. Rather, post-translational mechanisms appear to ultimately gate instructive retrograde communication. Finally, we find that a global increase in translation induces adaptive responses in both transcription and translation of protein chaperones and degradation factors to promote cellular proteostasis. Together, this demonstrates the power of ribosome profiling to define transcriptional, translational, and post-translational mechanisms driving retrograde signaling during adaptive plasticity.\n\nAUTHOR SUMMARYRecent advances in next-generation sequencing approaches have revolutionized our understanding of transcriptional expression in diverse systems. However, transcriptional expression alone does not necessarily report gene translation, the process of ultimate importance in understanding cellular function. To circumvent this limitation, biochemical tagging of ribosomes and isolation of ribosomally-associated mRNA has been developed. However, this approach, called TRAP, has been shown to lack quantitative resolution compared to a superior technology, ribosome profiling, which quantifies the number of ribosomes associated with each mRNA. Ribosome profiling typically requires large quantities of starting material, limiting progress in developing tissue-specific approaches. Here, we have developed the first tissue specific ribosome profiling system in Drosophila to reveal genome-wide changes in translation. We first demonstrate successful ribosome profiling from a specific tissue, muscle, with superior resolution compared to TRAP. We then use transcriptional and ribosome profiling to define transcriptional and translational adaptions necessary for synaptic signaling at the neuromuscular junction. Finally, we utilize ribosome profiling to demonstrate adaptive changes in cellular translation following cellular stress to muscle tissue. Together, this now enables the power of Drosophila genetics to be leveraged with translational profiling in specific tissues.

neuroscience↗

bioRxiv2017

An improved experimental model of cystic hydatid disease in liver resembling natural infection route with stable growing dynamics and immune reaction

Cystic echinococcosis is an endemic parasitic infection in Xinjiang, China and is causing serious economic burdens and public health concerns. An experimental murine model in vivo for hepatic cystic echinococcosis was established in C57B/6 mice by injection with human protoscolices via the portal vein of three different concentrations. Mice were followed up 10 months by ultrasound, gross anatomy, pathological and immunological examinations. The protoscolice migration in portal vein, hydatid cyst growth, host immune reaction and hepatic histopathology were examed periodicly. The infection rate of the mice in the high, medium, and low concentration groups were 90%, 100%, and 63.6%, respectively. The protoscolices migrate in the portal vein with blood flow, settle in the liver and develop into orthotopic hepatic hydatid cysts, resembling the natural infection route and course. This study established an improved experimental model of low biohazard risk but stable growing dynamics and immune reaction. It is especially useful for new anti-parasite medication trials agains hydatid disease.\n\nSummary statementAn experimental murine model of cystic echinococcosis was set up. This orthotopic model resembles primary infection route and natural infectious course with low biohazard risk and high efficiency.

pathology↗

bioRxiv2017

A programmable optical stimulator for the Drosophila eye

A programmable optical stimulator for Drosophila eyes is presented. The target application of the stimulator is to induce retinal degeneration in fly photoreceptor cells by exposing them to light in a controlled manner. The goal of this work is to obtain a reproducible system for studying age-related changes in susceptibility to environmental ocular stress. The stimulator uses light emitting diodes and an embedded computer to control illuminance, color (blue or red) and duration in two independent chambers. Further, the stimulator is equipped with per-chamber light and temperature sensors and a fan to monitor light intensity and to control temperature. An ON/OFF temperature control implemented on the embedded computer keeps the temperature from reaching levels that will induce the heat shock stress response in the flies. A custom enclosure was fabricated to house the electronic components of the stimulator. The enclosure provides a light-impermeable environment that allows air flow and lets users easily load and unload fly vials. Characterization results show that the fabricated stimulator can produce light at illuminances ranging from 0 to 16000 lux and power density levels from 0 to 7.2 mW/cm2 for blue light. For red light the maximum illuminance is 8000 lux which corresponds to a power density of 3.54 mW/cm2. The fans and the ON/OFF temperature control are able to keep the temperature inside the chambers below 28.17{degrees}C. Experiments with white-eye male flies were performed to assess the ability of the fabricated simulator to induce blue light-dependent retinal degeneration. Retinal degeneration is observed in flies exposed to 8 hours of blue light at 7949 lux. Flies in a control experiment with no light exposure show no retinal degeneration. Flies exposed to red light for the similar duration and light intensity (8 hours and 7994 lux) do not show retinal degeneration either. Hence, the fabricated stimulator can be used to create environmental ocular stress using blue light.\n\nO_TBL View this table:\norg.highwire.dtl.DTLVardef@15a02b6org.highwire.dtl.DTLVardef@681824org.highwire.dtl.DTLVardef@90692org.highwire.dtl.DTLVardef@8e6270org.highwire.dtl.DTLVardef@1e0e1d1_HPS_FORMAT_FIGEXP M_TBL O_TABLECAPTIONSpecifications table\n\nC_TABLECAPTION C_TBL

bioengineering↗

bioRxiv2017

Sugar metabolism changes in response to the ultraviolet B irradiation of peach (Prunus persica L.)

The protected cultivation of peach (Prunuspersica L.) trees is more economical and efficient than traditional cultivation, resulting in increased farmers incomes, but the peach sugar contents are lower than in open planting. In the greenhouse, a high-sugar variety of peach Lumi 1 was irradiated with 1.44 KJ{middle dot}m-2.d-1 intensity ultraviolet B radiation. The soluble sugar contents in fruit, peel and leaf were quantified using liquid chromatography. Overall, sucrose and sorbitol increased before the second fruit-expansion period. To further understand the mechanisms regulating sucrose and sorbitol accumulation in peach fruit, expression profiles of genes involved in sugar metabolism and transport were measured. The activity and translocation protein contents of these enzymes were measured by enzyme-linked immunosorbent assay. The increased sucrose synthase activity and sucrose transporter level in the pericarp promoted the synthesis of sucrose and intake of sucrose into fruit. Sorbitol transport into fruit was promoted by the increased sorbitol transporter protein levels in leaves. In summary, greenhouse the sucrose and sorbitol contents were increased when supplemented with 1.44 kJ{middle dot}m-2{middle dot}d-1 ultraviolet B radiation before the second fruit-expansion period of peach.

plant biology↗

bioRxiv2017

CAM: A Quality Control Pipeline For MNase-Seq Data

Nucleosome organization affects the accessibility of cis-elements to trans-acting factors. Micrococcal nuclease digestion followed by high-throughput sequencing (MNase-seq) is the most popular technology used to profile nucleosome organization on a genome-wide scale. Evaluating the data quality of MNase-seq data remains challenging, especially in mammalian. There is a strong need for a convenient and comprehensive approach to obtain dedicated quality control (QC) for MNase-seq data analysis. Here we developed CAM, which is a comprehensive QC pipeline for MNase-seq data. The CAM pipeline provides multiple informative QC measurements and nucleosome organization profiles on different potentially functional regions for given MNase-seq data. CAM also includes 268 historical MNase-seq datasets from human and mouse as a reference atlas for unbiased assessment. CAM is freely available at: http://www.tongji.edu.cn/~zhanglab/CAM

bioinformatics↗

bioRxiv2017

Polygenic Link Between Blood Lipids And Amyotrophic Lateral Sclerosis

Dyslipidemia is common among patients with amyotrophic lateral sclerosis (ALS). We aimed to test the association and causality between blood lipids and ALS, using polygenic analyses on the summary results of genome-wide association studies. Polygenic risk scores (PRS) based on low-density lipoprotein cholesterol (LDL-C) and total cholesterol (TC) risk alleles were significantly associated with a higher risk of ALS. Using single nucleotide polymorphisms (SNPs) specifically associated with LDL-C and TC as the instrumental variables, statistically significant causal effects of LDL-C and TC on ALS risk were identified in Mendelian randomization analysis. No significant association was noted between PRS based on triglycerides or high-density lipoprotein cholesterol risk alleles and ALS, and the PRS based on ALS risk alleles were not associated with any studied lipids. This study supports that high levels of LDL-C and TC are risk factors for ALS, and it also suggests a causal relationship of LDL-C and TC to ALS.

genetics↗

bioRxiv2017

A Balance Between Regulatory Constraints And Pathogen Pressure Shapes The Evolution Of Innate Immunity

As the first line of defence against pathogens, cells mount an innate immune response, which is highly variable from cell to cell. The response must be potent yet carefully controlled to avoid self-damage. How these constraints have shaped the evolution of innate immunity remains poorly understood. Here, we characterise this programmes transcriptional divergence between species and expression variability across cells. Using bulk and single-cell transcriptomics in primate and rodent fibroblasts challenged with an immune stimulus, we reveal a striking architecture of the innate immune response. Rapidly diverging genes, including cytokines and chemokines, also vary across cells and have distinct promoter structures. Conversely, genes involved in response regulation, such as transcription factors and kinases, are conserved between species and display low cell-to-cell variability. We suggest that this unique expression pattern, observed across species and conditions, has evolved as a mechanism for fine-tuned regulation, to achieve an effective but balanced response.

evolutionary biology↗

bioRxiv2017

Contribution Of Genetic Variation And Developmental Stage To Methylome Dynamics In Myeloid Differentiation

DNA methylation is important to establish a cells developmental identity. It also modulates cellular responses to endogenous developmental stimuli or environmental changes. We designed an in vitro myeloid differentiation model to analyze the genetic and developmental contribution to methylome dynamics using whole-genome bisulfide sequencing and transcriptome sequencing. Using a recursive partitioning approach, we identified 34,502 differentially methylated regions (DMRs) associated with genetic background and/or developmental stimuli. Specifically, 23,792 DMRs (69%) were significantly associated with inter-individual variations, of which 82% were associated with genetic polymorphisms in cis. Notably, inter-individual variations further modified 57 of 212 (26%) developmental DMRs with transcriptomic responses. Our study presents a novel analytical approach to determine the bona fide genetic contribution embedded in outlier patterns of CpG-SNPs in individual methylomes. This approach can be used to study genetic and epigenetic mechanisms underlying differential responses to developmental stimuli, environmental changes, and inter-individual differences in drug responses.

genomics↗

bioRxiv2017

VCF2CNA: A tool for efficiently detecting copy-number alteration in VCF genotype data

VCF2CNA is a web interface tool for copy-number alteration (CNA) analysis of VCF and other variant file formats. We applied it to 46 adult glioblastoma and 146 pediatric neuroblastoma samples sequenced by Illumina and Complete Genomics (CGI) platforms respectively. VCF2CNA was highly consistent with a state-of-the-art algorithm using raw sequencing data (mean F1-score=0.994) in high-quality glioblastoma samples and was robust to uneven coverage introduced by library artifacts. In the neuroblastoma set, VCF2CNA identified MYCN high-level amplifications in 31 of 32 clinically validated samples compared to 15 found by CGIs HMM-based CNA model. The findings suggest that VCF2CNA is an accurate, efficient and platform-independent tool for CNA analyses without accessing raw sequence data.

genomics↗

bioRxiv2017

A Comprehensive Assessment Of Reproducibility Of R-fMRI Metrics On The Impact Of Different Strategies For Multiple Comparison Correction And Small Sample Size

Concerns regarding reproducibility of resting-state functional magnetic resonance imaging (R-fMRI) findings have been raised. Little is known about how to operationally define R-fMRI reproducibility and to what extent it is affected by multiple comparison correction strategies and sample size. We comprehensively assessed two aspects of reproducibility, test-retest reliability and replicability, on widely used R-fMRI metrics in both between-subject contrasts of sex differences and within-subject comparisons of eyes-open and eyes-closed (EOEC) conditions. We noted permutation test with Threshold-Free Cluster Enhancement (TFCE), a strict multiple comparison correction strategy, reached the best balance between family-wise error rate (under 5%) and test-retest reliability / replicability (e.g., 0.68 for test-retest reliability and 0.25 for replicability of amplitude of low-frequency fluctuations (ALFF) for between-subject sex differences, 0.49 for replicability of ALFF for within-subject EOEC differences). Although R-fMRI indices attained moderate reliabilities, they replicated poorly in distinct datasets (replicability < 0.3 for between-subject sex differences, < 0.5 for within-subject EOEC differences). By randomly drawing different sample sizes from a single site, we found reliability, sensitivity and positive predictive value (PPV) rose as sample size increased. Small sample sizes (e.g., < 80 (40 per group)) not only minimized power (sensitivity < 2%), but also decreased the likelihood that significant results reflect \"true\" effects (PPV < 0.26) in sex differences. Our findings have implications for how to select multiple comparison correction strategies and highlight the importance of sufficiently large sample sizes in R-fMRI studies to enhance reproducibility.

neuroscience↗

bioRxiv2017

Cell proliferation depends on the direct binding between PKM2 and AKAP-Lbc

The M2 form of the glycolytic enzyme pyruvate kinase (PKM2) has generated much interest recently due to its important role in tumor metabolism. A yeast two-hybrid screen carried out by the Alliance for Cell Signaling suggests that PKM2 interacts with A-Kinase Anchoring Protein (AKAP)-Lbc.\n\nAKAP-Lbc (also known as AKAP13) is a scaffold protein that integrates signaling through multiple enzymes including protein kinases A and D and the small G protein Rho. AKAP-Lbc was originally identified in leukemic blast cells, and multiple reports implicate AKAP-Lbc in breast, prostate and thyroid cancers, however the role of AKAP-Lbc in cancer biology is not understood.\n\nCo-immunoprecipitation, pulldown and Bimolecular Fluorescence Complementation (BiFC) data indicate that PKM2 interacts with AKAP-Lbc. Mapping experiments indicate that PKM2 directly interacts with amino acid residues 1923-2817 of AKAP-Lbc. By disrupting the interaction between the two proteins with the expression of the AKAP-Lbc fragments, our data suggest that the binding between PKM2 and PKA plays a critical role in cell proliferation. The work indicates that the binding between AKAP-Lbc and PKM2 may be an important target to treat some cancers by reducing the cell proliferation.

biochemistry↗

bioRxiv2017

DATS: the data tag suite to enable discoverability of datasets

Todays science increasingly requires effective ways to find and access existing datasets that are distributed across a range of repositories. For researchers in the life sciences, discoverability of datasets may soon become as essential as identifying the latest publications via PubMed. Through an international collaborative effort funded by the National Institutes of Health (NIH)s Big Data to Knowledge (BD2K) initiative, we have designed and implemented the DAta Tag Suite (DATS) model to support the DataMed data discovery index. DataMeds goal is to be for data what PubMed has been for the scientific literature. Akin to the Journal Article Tag Suite (JATS) used in PubMed, the DATS model enables submission of metadata on datasets to DataMed. DATS has a core set of elements, which are generic and applicable to any type of datasets, and an extended set that can accommodate more specialized data types. DATS is a platform-independent model also available as a Schema.org annotated serialization to be used beyond DataMed, for example, in projects like DataCite.

bioinformatics↗

bioRxiv2017

The Effects of Sex and Diet on Physiology and Liver Gene Expression in Diversity Outbred Mice

Inter-individual variation in metabolic health and adiposity is driven by many factors. Diet composition and genetic background and the interactions between these two factors affect adiposity and related traits such as circulating cholesterol levels. In this study, we fed 850 Diversity Outbred mice, half females and half males, with either a standard chow diet or a high fat, high sucrose diet beginning at weaning and aged them to 26 weeks. We measured clinical chemistry and body composition at early and late time points during the study, and liver transcription at euthanasia. Males weighed more than females and mice on a high fat diet generally weighed more than those on chow. Many traits showed sex- or diet-specific changes as well as more complex sex by diet interactions. We mapped both the physiological and molecular traits and found that the genetic architecture of the physiological traits is complex, with many single locus associations potentially being driven by more than one polymorphism. For liver transcription, we find that local polymorphisms affect constitutive and sex-specific transcription, but that the response to diet is not affected by local polymorphisms. We identified two loci for circulating cholesterol levels. We performed mediation analysis by mapping the physiological traits, given liver transcript abundance and propose several genes that may be modifiers of the physiological traits. By including both physiological and molecular traits in our analyses, we have created deeper phenotypic profiles to identify additional significant contributors to complex metabolic outcomes such as polygenic obesity. We make the phenotype, liver transcript and genotype data publicly available as a resource for the research community.

genetics↗

bioRxiv2016

Mocap: Large-scale inference of transcription factor binding sites from chromatin accessibility

Differential binding of transcription factors (TFs) at cis-regulatory loci drives the differentiation and function of diverse cellular lineages. Understanding the regulatory interactions that underlie cell fate decisions requires characterizing TF binding sites (TFBS) across multiple cell types and conditions. Techniques, e.g. ChIP-Seq can reveal genome-wide patterns of TF binding, but typically requires laborious and costly experiments for each TF-cell-type (TFCT) condition of interest. Chromosomal accessibility assays can connect accessible chromatin in one cell type to many TFs through sequence motif mapping. Such methods, however, rarely take into account that the genomic context preferred by each factor differs from TF to TF, and from cell type to cell type. To address the differences in TF behaviors, we developed Mocap, a method that integrates chromatin accessibility, motif scores, TF footprints, CpG/GC content, evolutionary conservation and other factors in an ensemble of TFCT-specific classifiers. We show that integration of genomic features, such as CpG islands improves TFBS prediction in some TFCT. Further, we describe a method for mapping new TFCT, for which no ChIP-seq data exists, onto our ensemble of classifiers and show that our cross-sample TFBS prediction method outperforms several previously described methods.

bioinformatics↗

bioRxiv2016

An improved de novo pipeline for enrichment of high diversity mitochondrial genomes from Amphibia to high-throughput sequencing

We present an improved de novo pipeline by combining long-range polymerase chain reaction (LR-PCR) and capture hybridization for enriching mitochondrial DNA to high-throughput sequencing. We test a new set of primers and hybridizing long-range library (LR-HY) with 112 mitochondrial genomes (MtG) representing three orders, 12 families, 54 genera, and 106 species of Amphibia. The primers are used for obtaining wide taxonomic MtG amplicons to sequence directly and/or make probes for closely related species. LR-HY is compared to standard hybridization. The primers successfully amplify 82 MtGs from all three order, all families, 92.6% (50/54) of the genera, and 74.5% (79/106) of the species, despite some DNA degradation and gene rearrangement. We observe a significantly negative correlation between sequence depth and gene variation. The pattern of highly variable regions is separately distributed in different regions within the length of < 4 kb in the 33-pooled sample. We demonstrate that using 2 kb libraries generate deeper sequence coverage in the highly variable loci than using 400 bp libraries. In total, the pipeline successfully recovers 83 complete and 14 almost complete MtGs from 53 of 54 genera, including 14 MtGs had rearranged protein-coding genes. This universal primers combined with LR-HY is an efficient way to enrich complete MtGs across the entire Amphibia.

genomics↗