quantitative transcriptomics
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BACKGROUND: Understanding the genetic basis of novel traits is a central topic in evolutionary biology. Two novel pigmentation phenotypes, egg-spots and blotches, emerged during the rapid diversification of East African cichlid fishes. Egg-spots are circular pigmentation markings on the anal fins of hundreds of derived haplochromine cichlids species, whereas blotches are patches of conspicuous anal fin pigmentation with ill-defined boundaries that occur in few species that belong to basal cichlid lineages. Both traits play an important role in the breeding behavior of this group of fishes. Knowledge about the origin, homology and underlying genetics of these pigmentation traits is sparse. RESULTS: Here, we present a comparative transcriptomic and differential gene expression analysis of egg-spots and blotches. We first conducted an RNA sequencing experiment where we compared egg-spot tissue with the remaining portion of egg-spot-free fin tissue using six individuals of Astatotilapia burtoni. We identified 1229 differentially expressed genes between the two tissue types. We then showed that rates of evolution of these genes are higher than average estimated on whole transcriptome data. Using quantitative real-time PCR, we found that 29 out of a subset of 46 differentially expressed genes showed an analogous expression pattern in another haplochromine species' egg-spots, Cynotilapia pulpican, strongly suggesting that these genes are involved in the egg-spot phenotype. Among these are the previously identified egg-spot gene fhl2a, two known patterning genes (hoxC12a and bmp3) as well as other pigmentation related genes such as asip. Finally, we analyzed the expression patterns of the same gene subset in two species that feature blotches instead of egg-spots, one haplochromine species (Pseudocrenilabrus philander) and one ectodine species (Callochromis macrops), revealing that the expression patterns in blotches and egg-spots are rather distinct. CONCLUSIONS: We identified several candidate genes that will serve as an important and useful resource for future research on the emergence and diversification of cichlid fishes' egg-spots. Only a limited degree of conservation of gene expression patterns was detected between the egg-spots of the derived haplochromines and blotches from ancestral haplochromines, as well as between the two types of blotches, suggesting an independent origin of these traits.
- MeSH
- anální kanál fyziologie MeSH
- cichlidy genetika MeSH
- druhová specificita MeSH
- fylogeneze MeSH
- molekulární evoluce MeSH
- pigmentace kůže genetika MeSH
- ploutve zvířat fyziologie MeSH
- regulace genové exprese MeSH
- rybí proteiny genetika MeSH
- sekvenční analýza RNA metody MeSH
- stanovení celkové genové exprese metody MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- srovnávací studie MeSH
The aim of this work was to identify reliable reference genes for expression studies in adult Haemonchus contortus. Eleven candidate genes were identified and the stability of their expression was assessed in adult males and females of two genetically divergent H. contortus isolates: drug-susceptible (ISE) and multi-drug-resistant (WR). Five genes with the most stable expression patterns were further assessed for suitability as reference genes in anthelmintic-treated H. contortus adults versus non-treated controls. We identified important differences in the expression of a number of candidate genes in anthelmintic-treated samples, confirming the need for careful validation of control genes for such experiments. We propose the use of multiple reference genes for expression studies in this species and found gpd, ama and far most suitable for adult H. contortus.
- MeSH
- anthelmintika farmakologie MeSH
- Haemonchus účinky léků genetika MeSH
- kvantitativní polymerázová řetězová reakce metody normy MeSH
- referenční standardy * MeSH
- stanovení celkové genové exprese metody normy MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
One third of the world's population is latently infected with Mycobacterium tuberculosis (Mtb) and up to 10% of infected individuals develop active tuberculosis (TB) in their lifetime. Among the major challenges in the control of TB is the implementation of sensitive methods for detection of latent tuberculosis infection (LTBI). Currently, in vitro interferon gamma release assays, yielding single value readout, are used as an alternative to the traditional tuberculin skin test for the diagnosis of LTBI. More complex characterization of immune status of LTBI individuals, however, is desirable for indication of LTBI subjects for preventative chemotherapy. Here we describe a quantitative polymerase chain reaction (qPCR) for determination of expression levels of 14 genes, additional to interferon gamma, which was applied for comparison of the specific Mtb-antigen immune response of blood cells from healthy, latently infected, and TB individuals. With the use of principal component analysis and discriminant analysis, a pattern of mRNA levels of 6 genes was identified, allowing discrimination of healthy individuals from active TB and LTBI subjects. These results open the way to development of multimarker qPCR for the detection of LTBI.
- MeSH
- antigeny bakteriální imunologie MeSH
- diagnostické techniky molekulární metody MeSH
- dospělí MeSH
- kvantitativní polymerázová řetězová reakce metody MeSH
- latentní tuberkulóza diagnóza MeSH
- leukocyty mononukleární imunologie MeSH
- lidé středního věku MeSH
- lidé MeSH
- Mycobacterium tuberculosis imunologie MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- stanovení celkové genové exprese metody MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- hodnotící studie MeSH
- práce podpořená grantem MeSH
Accurate gene expression measurements are essential in studies of both crop and wild plants. Reverse transcription quantitative real-time PCR (RT-qPCR) has become a preferred tool for gene expression estimation. A selection of suitable reference genes for the normalization of transcript levels is an essential prerequisite of accurate RT-qPCR results. We evaluated the expression stability of eight candidate reference genes across roots, leaves, flower buds and pollen of Silene vulgaris (bladder campion), a model plant for the study of gynodioecy. As random priming of cDNA is recommended for the study of organellar transcripts and poly(A) selection is indicated for nuclear transcripts, we estimated gene expression with both random-primed and oligo(dT)-primed cDNA. Accordingly, we determined reference genes that perform well with oligo(dT)- and random-primed cDNA, making it possible to estimate levels of nucleus-derived transcripts in the same cDNA samples as used for organellar transcripts, a key benefit in studies of cyto-nuclear interactions. Gene expression variance was estimated by RefFinder, which integrates four different analytical tools. The SvACT and SvGAPDH genes were the most stable candidates across various organs of S. vulgaris, regardless of whether pollen was included or not.
- MeSH
- komplementární DNA genetika MeSH
- kvantitativní polymerázová řetězová reakce metody MeSH
- polymerázová řetězová reakce s reverzní transkripcí metody MeSH
- rostlinné geny * MeSH
- sekvenční analýza RNA MeSH
- Silene genetika MeSH
- stanovení celkové genové exprese MeSH
- Publikační typ
- časopisecké články MeSH
- validační studie MeSH
Histologically verified pairs (n=10) of pancreatic tumors and non-neoplastic tissues were used for quantitative real-time PCR and the stability of 24 reference genes was analyzed with geNorm and NormFinder software. Raw C{q} values correlated with the degree of RNA degradation. This correlation was abolished by normalization to C{q} of 18S endogenous control gene. Both geNorm and NormFinder programs suggested EIF2B1, ELF1, MRPL19, and POP4 as the same most stable genes. We have thus identified suitable reference genes for future expression studies in pancreatic carcinoma. Normalization method reducing the effects of RNA degradation on the quality of results was also developed.
- MeSH
- eukaryotický iniciační faktor 2B genetika MeSH
- exprese genu MeSH
- jaderné proteiny genetika MeSH
- karcinom diagnóza genetika patologie MeSH
- kvantitativní polymerázová řetězová reakce MeSH
- lidé středního věku MeSH
- lidé MeSH
- mitochondriální proteiny genetika MeSH
- nádorové biomarkery genetika MeSH
- nádory slinivky břišní diagnóza genetika patologie MeSH
- pankreas metabolismus patologie MeSH
- ribonukleasy genetika MeSH
- ribonukleoproteiny genetika MeSH
- ribozomální proteiny genetika MeSH
- senioři MeSH
- software MeSH
- stabilita RNA MeSH
- stanovení celkové genové exprese MeSH
- transkripční faktory genetika MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Hypertension in humans and experimental models has a strong hereditary basis, but identification of causative genes remains challenging. Quantitative trait loci (QTLs) for hypertension and salt sensitivity have been reported on rat chromosome 18. We set out to genetically isolate and prioritize genes within the salt-sensitivity and hypertension QTLs on the spontaneously hypertensive rat (SHR) chromosome 18 by developing and characterizing a series of congenic strains derived from the SHR and normotensive Brown Norway rat strains. The SHR.BN-D18Rat113/D18Rat82 congenic strain exhibits significantly lower blood pressure and is salt resistant compared with the SHR. Transplantation of kidneys from SHR.BN-D18Rat113/D18Rat82 donors into SHR recipients is sufficient to attenuate increased blood pressure but not salt sensitivity. Derivation of congenic sublines allowed for the separation of salt sensitivity from hypertension QTL regions. Renal expression studies with microarray and Solexa-based sequencing in parental and congenic strains identified 4 differentially expressed genes within the hypertension QTL region, one of which is an unannotated transcript encoding a previously undescribed, small, nonprotein coding RNA. Sequencing selected biological candidate genes within the minimal congenic interval revealed a nonsynonymous variant in SHR transcription factor 4. The minimal congenic interval is syntenic to a region of human chromosome 18 where significant linkage to hypertension was observed in family based linkage studies. These congenic lines provide reagents for identifying causative genes that underlie the chromosome 18 SHR QTLs for hypertension and salt sensitivity. Candidate genes identified in these studies merit further investigation as potentially causative hypertension genes in SHR and human hypertension.
- MeSH
- genetická predispozice k nemoci genetika MeSH
- hypertenze etiologie genetika patofyziologie MeSH
- jednonukleotidový polymorfismus MeSH
- krevní tlak fyziologie genetika MeSH
- krysa rodu rattus MeSH
- kuchyňská sůl škodlivé účinky MeSH
- ledviny metabolismus MeSH
- lokus kvantitativního znaku genetika MeSH
- mapování chromozomů MeSH
- northern blotting MeSH
- polymerázová řetězová reakce s reverzní transkripcí MeSH
- potkani inbrední BN MeSH
- potkani inbrední SHR MeSH
- proteiny regulující apoptózu genetika MeSH
- receptor melanokortinový typ 2 genetika MeSH
- receptor melanokortinový typ 4 genetika MeSH
- receptory melanokortinové genetika MeSH
- savčí chromozomy genetika MeSH
- sekvenční analýza hybridizací s uspořádaným souborem oligonukleotidů MeSH
- stanovení celkové genové exprese MeSH
- transplantace ledvin metody MeSH
- tyrosinfosfatasa nereceptorového typu 2 genetika MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH
Formalin-fixed, paraffin-embedded (FFPE) tissue is the most common tissue specimen available after microscopic examination. Molecular methods, such as polymerase chain reaction (PCR) and gene expression examination, serve as a source of diagnostic and prognostic information but require high-quality RNA. However, the increasing application of RNA extracted from FFPE tissue frequently results in very small and degraded quantities of nucleic acid. This study targets gene expression analysis from FFPE specimens using real-time quantitative PCR. The whole protocol consists of several steps, that is, RNA extraction and its quality control, reverse transcription, and fluorescence detection during real-time quantitative PCR. We compared several methods in each step, chose the most effective, and with that combination we successfully examined 95% (62 from 65) FFPE samples for our genes of interest. We reached the best results with RNA isolation by using a commercial kit, carefully interpreted UV spectrophotometric values, and meticulously chose reverse transcriptase and TaqMan fluorescence detection. Our protocol improves the utility of FFPE tissue for molecular profiling studies.
- MeSH
- fixativa farmakologie MeSH
- formaldehyd farmakologie MeSH
- lidé MeSH
- odběr biologického vzorku metody MeSH
- patologie metody MeSH
- polymerázová řetězová reakce metody MeSH
- RNA genetika izolace a purifikace MeSH
- stanovení celkové genové exprese metody MeSH
- uchovávání tkání MeSH
- zalévání tkání do parafínu MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- hodnotící studie MeSH
- práce podpořená grantem MeSH
BACKGROUND: Reference genes are commonly used as the endogenous normalisation measure for the relative quantification of target genes. The appropriate application of quantitative real-time PCR (RT-qPCR), however, requires the use of reference genes whose level of expression is not affected by the test, by general physiological conditions or by inter-individual variability. For this purpose, seven reference genes were investigated in tissues of the most important cereals (wheat, barley and oats). Titre of Barley yellow dwarf virus (BYDV) was determined in oats using relative quantification with different reference genes and absolute quantification, and the results were compared. RESULTS: The expression of seven potential reference genes was evaluated in tissues of 180 healthy, physiologically stressed and virus-infected cereal plants. These genes were tested by RT-qPCR and ranked according to the stability of their expression using three different methods (two-way ANOVA, GeNorm and NormFinder tools). In most cases, the expression of all genes did not depend on abiotic stress conditions or virus infections. All the genes showed significant differences in expression among plant species. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH), beta-tubulin (TUBB) and 18S ribosomal RNA (18S rRNA) always ranked as the three most stable genes. On the other hand, elongation factor-1 alpha (EF1A), eukaryotic initiation factor 4a (EIF4A), and 28S ribosomal RNA (28S rRNA) for barley and oat samples; and alpha-tubulin (TUBA) for wheat samples were consistently ranked as the less reliable controls.The BYDV titre was determined in two oat varieties by RT-qPCR using three different quantification approaches. There were no significant differences between the absolute and relative quantifications, or between quantification using GAPDH + TUBB + TUBA +18S rRNA and EF1A + EIF4A + 28S rRNA. However, there were discrepancies between the results of individual assays. CONCLUSIONS: The geometric average of GAPDH, 18S rRNA and TUBB is suitable for normalisation of BYDV quantification in barley tissues. For wheat and oat samples, a combination of four genes is necessary: GAPDH, 18S rRNA, TUBB and EIF4A for wheat; and GAPDH, 18S rRNA, TUBB and TUBA for oat is recommended.
- MeSH
- jedlá semena genetika virologie MeSH
- Luteovirus fyziologie MeSH
- polymerázová řetězová reakce s reverzní transkripcí metody MeSH
- reprodukovatelnost výsledků MeSH
- RNA ribozomální 18S analýza genetika MeSH
- rostlinné geny genetika MeSH
- rostlinné proteiny genetika metabolismus MeSH
- stanovení celkové genové exprese metody MeSH
- virová nálož MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The fungus Claviceps purpurea is a biotrophic phytopathogen widely used in the pharmaceutical industry for its ability to produce ergot alkaloids (EAs). The fungus attacks unfertilized ovaries of grasses and forms sclerotia, which represent the only type of tissue where the synthesis of EAs occurs. The biosynthetic pathway of EAs has been extensively studied; however, little is known concerning its regulation. Here, we present the quantitative transcriptome analysis of the sclerotial and mycelial tissues providing a comprehensive view of transcriptional differences between the tissues that produce EAs and those that do not produce EAs and the pathogenic and non-pathogenic lifestyle. The results indicate metabolic changes coupled with sclerotial differentiation, which are likely needed as initiation factors for EA biosynthesis. One of the promising factors seems to be oxidative stress. Here, we focus on the identification of putative transcription factors and regulators involved in sclerotial differentiation, which might be involved in EA biosynthesis. To shed more light on the regulation of EA composition, whole transcriptome analysis of four industrial strains differing in their alkaloid spectra was performed. The results support the hypothesis proposing the composition of the amino acid pool in sclerotia to be an important factor regulating the final structure of the ergopeptines produced by Claviceps purpurea.
- MeSH
- biotechnologie MeSH
- Claviceps genetika metabolismus MeSH
- exprese genu MeSH
- fungální proteiny genetika metabolismus MeSH
- geny hub MeSH
- jednonukleotidový polymorfismus MeSH
- námelové alkaloidy biosyntéza MeSH
- oxidační stres MeSH
- peptidsynthasy genetika metabolismus MeSH
- průmyslová mikrobiologie MeSH
- sekvence aminokyselin MeSH
- sekvenční homologie aminokyselin MeSH
- stanovení celkové genové exprese MeSH
- Publikační typ
- časopisecké články MeSH
This study sought to reveal the proteomic profiling of methicillin-resistant Staphylococcus aureus (MRSA)-derived extracellular vesicles (EVs) after exposure to imipenem. The advanced isobaric tags for relative and absolute quantitation (iTRAQ®) proteomic approach were used to analyze the alterations in MRSA-derived EV protein patterns upon exposure to imipenem. A total of 1260 EV proteins were identified and quantified. Among these, 861 differentially expressed exosome proteins (P < 0.05) were found. Multivariate analysis, Gene Ontology (GO) annotation, and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were used to analyze the identified proteins. Enrichment analysis of GO annotations indicated that imipenem primarily regulated the metabolic processes in MRSA. The metabolism of differentially expressed proteins was found to be the most significant in the combined analysis of the KEGG pathway analysis. Based on the results from the STRING analysis, 50S ribosomal protein L16 (RplP) and 30S ribosomal protein S8 (RpsH) were involved in the imipenem-induced MRSA-derived EVs. These results provide vital information on MRSA-derived EVs, increasing our knowledge of the proteome level changes in EVs upon exposure to imipenem. Moreover, these results pave the way for developing novel MRSA treatments.