Expression analysis vectors for Aspergillus niger.
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The Drosophila Notch gene has been shown to be involved in the determination of fate in a number of different cell types. Similarly, Notch homologues in Caenorhabditis elegans are involved in cell decision-making steps. It is of interest to determine if a mammalian Notch homologue plays a role in cell fate determination. We have isolated cDNA from a mouse Notch gene using low-stringency hybridization with probes derived from the Xenopus Notch gene. Sequence analysis reveals that this gene possesses EGF repeats, Notch/lin-12 repeats, and CDC-10/SWI-6 repeats, characteristic of other Notch homologues. Northern analysis revealed that the transcript size was roughly 10 kb as has been found for the other Notch genes. We have studied the expression pattern of the gene by both conventional and whole mount in situ hybridization. Expression patterns were consistent with mouse Notch having a determinative role in the formation of mesoderm, somites, and the nervous system.
Chalcone synthase (CHS) is a pivotal enzyme in flavonoid biosynthesis involved in plant development, defense, and secondary metabolism. Xanthoceras sorbifolium (yellowhorn) is a medicinal and ornamental species with high resistance to environmental stresses, but its CHS gene family remains uncharacterized. We performed a pangenome-wide identification of CHS genes across five yellowhorn genomes (Xzs4, Xwf8, Xjg, Xg11, and Xzg2). Across the five yellowhorn genomes, 27 CHS genes were identified and classified into four core pangenes, present in all five genomes, and two dispensable genes, present only in a subset of genomes. Phylogenetic analysis grouped these genes into three major clades, and chromosomal mapping and duplication analyses identified four tandemly duplicated gene pairs under purifying selection. The analyses of conserved structural features, including protein motifs and exon-intron organization, together with promoter cis-regulatory elements and gene ontology annotation, further indicated the potential involvement of CHS genes in flavonoid biosynthesis and stress-responsive mechanisms. Gene expression profiling identified significant upregulation of Xg11_CHS1 and Xg11_CHS3 under cold and drought stress, with tissue-specific expression patterns. These findings provide valuable insights into the evolution, functional diversification, and stress-responsive roles of the CHS gene family, identifying candidate genes for future studies targeting stress tolerance and flavonoid biosynthesis in yellowhorn.
BACKGROUND: Long-chain non-coding RNAs (lncRNAs) play various roles in the regulation of gene expression at the levels of transcription and translation, and epigenetic modification. Dysregulation of lncRNAs is associated with various malignancies, including cancer. lncRNAs have been demonstrated to regulate critical biological processes in cancer cells, such as apoptosis, proliferation, migration, and invasion. They also play essential roles in the development of gastric cancer (GC). However, the clinical significance and biological function of many lncRNAs remain unexplored in GC progression. This study aimed to evaluate the expression profiles of LINC00671 and LINC01913 in GC patients and investigate their correlation with epithelial-to-mesenchymal transition (EMT) markers. METHOD: The real-time PCR technique was applied to measure the expression levels of the selected lncRNAs (LINC01913 and LINC00671) and EMT-related mRNAs (MAMLs and MMP-13) in 83 tumor and adjacent normal tissues obtained from GC patients. RESULT: A significant reduction in LINC00671 expression was observed in 55.4% of tumor tissues, while elevated expression of LINC01913 (41%), MMP13 (56.6%), and MAML1 (44.6%) was detected, representing the proportion of samples with dysregulated expression relative to matched normal tissues. Dysregulation of these genes was significantly associated with various clinicopathological features (P < 0.05), supporting a potential link between these lncRNAs and EMT processes in GC. CONCLUSION: The observed associations between LINC00671, LINC01913, and EMT-related genes suggest their potential as prognostic biomarkers for treatment response in GC patients.
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Calcium-dependent protein kinases (CDPKs) serve as calcium ion sensors and play crucial roles in all aspects of plant life cycle. While CDPK gene family has been extensively studied in various plants, there is limited information available for CDPK members in oat, an important cereal crop worldwide. Totally, 60 AsCDPK genes were identified in oat genome and were classified into four subfamilies based on their phylogenetic relationship. The members within each subfamily shared similar gene structure and conserved motifs. Collinearity analysis revealed that AsCDPK gene amplification was attributed to segmental duplication events and underwent strong purifying selection. AsCDPK promoters were predicted to contain cis-acting elements associated with hormones, biotic and abiotic stresses. AsCDPK gene expressions were induced by different salt stresses, exhibiting stress-specific under different salt treatments. Moreover, overexpression of AsCDPK26 gene enhanced salt resistance in C. reinhardtii, a single-cell photoautotrophic model plants. Further analysis revealed a significant correlation between AsCDPK26 and Na+/H+ antiporter 1 (p<0.05), suggesting that AsCDPK26 may interact with ion transporter to modulate salt resistance. These results not only provide valuable insights into AsCDPK genes in response to different salt stresses, but also lay the foundation to mine novel candidates for improving salt tolerance in oat and other crops.
Fumarylacetoacetate hydrolase (FAH) is an enzyme which is deficient in human hereditary tyrosinemia type 1. We have cloned and sequenced a rat liver cDNA encoding FAH. The identity of the clone was ascertained by hybrid-selection experiments and deduced amino acid (aa) sequence homologies with sequenced oligopeptide fragments of the purified rat liver protein. The cDNA codes for a 419-aa protein of 45,946 daltons. We used this cDNA as a probe in conjunction with a specific anti-rat FAH antibody to study the expression pattern of the FAH gene in rat liver and kidney. Northern blot analysis indicates that the kidney contains slightly more FAH mRNA that the liver. Western blotting shows, however, that the liver contains about twice as much FAH protein as the kidney. Primer extension experiments suggest that there are no differences in the 5'-untranslated (UT) ends of the FAH mRNA of both tissues. We conclude that synthesis of the FAH protein is in part regulated at the post-transcriptional level in rats liver and kidney, and that this regulation does not appear to be mediated by the 5'-UT sequence of the FAH mRNA.
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Seeds of the Pinto cultivar of the common bean, Phaseolus vulgaris, are deficient in phytohemagglutinin (PHA), a lectin normally composed of two different polypeptides (PHA-E and PHA-L). In Pinto seeds, there is no PHA-E and only small amounts of PHA-L. The gene coding for the Pinto PHA-E, Pdlec1, is a pseudogene as a result of a single base pair deletion in codon 11, causing a frameshift and premature termination of translation. This mutation explains the absence of the PHA-E polypeptide but not the several-hundredfold reduction of the cytoplasmic Pdlec1 mRNA in developing seeds when compared with a normal PHA-E gene. To find the cause for this reduction in mRNA levels, we swapped gene fragments of Pdlec1 with the homologous parts of a normal PHA gene from the cultivar Greensleeves and introduced these fusions into tobacco. Analysis of the transgenic seeds showed that the Pdlec1 promoter is fully functional. We also repaired the Pdlec1 coding frame in vitro and inserted the repaired and unrepaired versions into a PHA gene expression cassette. In transgenic tobacco, both constructs showed Pdlec1 transcript accumulation in the second half of seed maturation. The single-base frame repair boosted the peak transcript levels by a factor of 40 and resulted in the synthesis of PHA-E at normal levels. We propose that the premature translational stop caused by the frameshift leads to a faster breakdown of the Pdlec1 mRNA, thereby preventing this transcript from accumulating to high levels.
Differences in the tumor biology of ovarian carcinomas probably influence operability and response to chemotherapy which are the most relevant prognostic factors. The phenotype of different malignant epithelial tumors including ovarian carcinomas is obviously associated with an activation of the EGF/TGFa signal pathway. When we analysed the expression of EGF-R and TGFa with biochemical, molecular-chemical and immunohistochemical methods in 29 different ovarian carcinomas, we found a correlation between the mRNA and protein levels of EGF-R as well as TGFa for tumors with low or high expressing rates. However, the concentration of measurable free EGF-Rs seems to depend on the amount of TGFa expression by the tumors. The EGF-R binding ligand TGFa is produced by the tumor cells; stromal cells are TGFa negative as shown by immunohistochemistry. By the use of an immunostaining index the TGFa protein concentration was measured semiquantitatively, classifying tumors according to their TGFa production rate. The comparison of TGFa mRNA amounts and staining index supports the hypothesis that TGFa is modified posttranslationally. EGF-R or TGFa expressing ovarian carcinomas had a high response rate to chemotherapy, whereas the EGF-R or TGFa negative tumors mostly exhibit a no change or progressive disease behaviour. These findings are the basis for our assumption that ovarian carcinomas with the basis for our assumption that ovarian carcinomas with an activated EGF-TGFa system are tumor biologically different compared to the EGF-R/TGFa negative tumors.
Bluetongue virus (BTV) VP6 is often resolved into two closely migrating bands by SDS-PAGE (VP6 and VP6a). RNA segment 9 of BTV-serotype 1 South Africa (encoding VP6) has been cloned as cDNA, and the complete sequence has been determined. Expression of this clone both in vitro and in tissue culture produced the same polypeptide doublet as seen previously in extracts from BTV-infected cells. Modification of the cDNA, including the removal of the first initiation codon, demonstrated that the two forms of VP6 are derived from initiation of protein synthesis at two distinct sites and not by post-translational modification.
The metabolic functions of insulin-like growth factors (IGFs) I and II are modulated by a family of binding proteins which are present in biological fluids and are synthesized by a variety of cell types. A cDNA clone, isolated at random from a subtracted human retina library, has been identified to code for a novel IGF-binding protein (IGFBP2) by its sequence homology to the peptide sequence of IGF binding proteins purified from bovine MDBK and rat BRL-3A cells. The complete nucleotide sequence of the IGFBP2 cDNA is 1406 bp long, contains 66% G-Cs and an open reading frame of 328 amino acids with a putative signal or pro-peptide of 39 residues. The mature polypeptide of 289 amino acids has 18 cysteines, a putative ATP-binding site and an RGD tripeptide. The 1.4 kb IGFBP2 transcript is expressed in several human tissues including fetal eye and fetal brain, but not in the human lymphoblastoid cell line against which the retinal cDNA library was subtracted. In situ hybridization to sections of mouse retina localized the mRNA for IGFBP2 primarily in the outer nuclear layer of photoreceptors. Southern blot analysis of DNA from human x rodent and mouse x rodent somatic cell hybrids assigned the gene for IGFBP2 to human chromosome 2q33-qter and mouse chromosome 1 in a known conserved syntenic region.
While only two gamma-crystallins have been identified in the human eye lens, molecular studies indicate that the human gamma-crystallins are encoded in a multigene family comprising at least seven closely related members. Sequence analysis of five of these genes has suggested that three (gamma 1-2, G3, and G4) are potentially active, while two (G1 psi and G2 psi) correspond to closely related pseudogenes. Here we report on the detailed structure of a sixth gamma-crystallin gene, G5, and our results obtained with transient expression assays to characterize both the promoter activity and translation products of five members of the gene family. We show that 5'-flanking sequences of G1 psi and G2 psi lacked detectable promoter activity, while the corresponding sequences of G3, G4, and G5 were able to direct high levels of expression of the bacterial chloramphenicol acetyltransferase gene in primary lens epithelia, but not in cultures of nonlens origin. Detailed sequence comparisons indicated that active genes contained several conserved sequence tracts 5' of the TATA box which may constitute functional elements of a lens-specific gamma-crystallin promoter. Expression of the gamma-crystallin coding sequences from the human metallothionein IIA promoter in nonlens cells facilitated characterization of the polypeptides encoded by individual gamma-genes and, in future studies, should permit comparison of these proteins with distinct gamma-crystallins in the human lens.
We isolated and analysed a full-length mouse brain glutamate dehydrogenase (GLUD) cDNA as a preliminary step to use the mouse model for the investigation of GLUD function in neurotransmission and neurodegeneration. GLUD coding sequences were found highly conserved among mouse, human and rat. Northern blots revealed two transcripts with different ratios in different mouse organs implying some mechanism of tissue-specific expression. In contrast to human, mouse GLUD gene family appears not to contain an intronless member.
Migraine is a common disabling neurovascular brain disorder typically characterised by attacks of severe headache and associated with autonomic and neurological symptoms. Migraine is caused by an interplay of genetic and environmental factors. Genome-wide association studies (GWAS) have identified over a dozen genetic loci associated with migraine. Here, we integrated migraine GWAS data with high-resolution spatial gene expression data of normal adult brains from the Allen Human Brain Atlas to identify specific brain regions and molecular pathways that are possibly involved in migraine pathophysiology. To this end, we used two complementary methods. In GWAS data from 23,285 migraine cases and 95,425 controls, we first studied modules of co-expressed genes that were calculated based on human brain expression data for enrichment of genes that showed association with migraine. Enrichment of a migraine GWAS signal was found for five modules that suggest involvement in migraine pathophysiology of: (i) neurotransmission, protein catabolism and mitochondria in the cortex; (ii) transcription regulation in the cortex and cerebellum; and (iii) oligodendrocytes and mitochondria in subcortical areas. Second, we used the high-confidence genes from the migraine GWAS as a basis to construct local migraine-related co-expression gene networks. Signatures of all brain regions and pathways that were prominent in the first method also surfaced in the second method, thus providing support that these brain regions and pathways are indeed involved in migraine pathophysiology.
Platelet-derived growth factor (PDGF) is generally considered to stimulate phosphoinositide turnover resulting in activation of protein kinase C and increased cytoplasmic [Ca2+]. We have examined the role of these secondary effects in regulation of c-myc mRNA accumulation in the MG-63 human osteogenic sarcoma line. Treatment of quiescent cells with 12-O-tetradecanoyl phorbol-13-acetate (TPA) to down-regulate protein kinase C inhibited TPA-stimulated c-myc expression but did not affect the PDGF-modulated process. When cytoplasmic [Ca2+] was increased by addition of a Ca2+ ionophore (A23187 or ionomycin), no stimulation of c-myc RNA was seen; furthermore, these agents did not enhance the PDGF-modulated c-myc expression. Addition of EGTA to cultures treated with both PDGF and a Ca2+ ionophore did not inhibit c-myc induction but rather caused a superinduction of c-myc RNA accumulation. Superinduction occurred only if the [EGTA] was greater than [Ca2+] in the medium. This superinduction was distinct from the increased induction caused by inhibition of protein synthesis. Because PDGF-induced c-myc expression is independent of protein kinase C and increased cytoplasmic [Ca2+], the evidence suggests that PDGF modulates c-myc RNA accumulation in MG-63 cells via a novel pathway, seemingly uncoupled from the classic action of increased phosphoinositide metabolism.
Heat shock proteins (HSPs) are a group of evolutionarily conserved molecular chaperones that serve as indispensable core regulators in preserving cellular homeostasis and orchestrating organismal stress responses. The tropical sea cucumber Stichopus monotuberculatus, a high-value aquaculture species, is sensitive to fluctuations in environmental salinity-a challenge that has emerged as a critical bottleneck limiting its large-scale commercial cultivation. However, no systematic investigation has been conducted to characterize the HSP70 superfamily in S. monotuberculatus and elucidate its functional roles in salinity adaptation. In the present study, we performed a comprehensive genome-wide scan and identified 19 HSP70 superfamily genes in the S. monotuberculatus genome, with the HSP70IV subfamily showing remarkable gene expansion, containing 8 distinct copies. Phylogenetic analysis, conserved motif identification, and gene structure characterization demonstrated high evolutionary conservation within each HSP subfamily. These genes were unevenly distributed across the chromosomes of S. monotuberculatus, and prediction of cis-acting elements revealed that their upstream regulatory regions were enriched with numerous functional elements associated with stress response and immune regulation. Salinity stress experiments revealed that under severe low-salinity conditions (18‰), the expression levels of SmHSPA14L and multiple HSP70IV subfamily members were significantly elevated, while SmHYOU1D was significantly downregulated; in contrast, only subtle changes were detected in the expression of most HSP70 genes under moderate low-salinity stress (24‰). These findings strongly suggest that HSP70 genes, particularly the expanded HSP70IV subfamily, may act as key modulators in the low-salinity stress response. This work provides valuable insight into the molecular mechanisms underlying salinity adaptation in tropical sea cucumbers.
Ruditapes philippinarum is an economically important bivalve species in China, and shell color is a trait of ecological and commercial significance. Melanin is a key determinant of shell color, and members of the CREB/ATF family have been reported to participate in melanogenesis in other organisms. In this study, members of the CREB/ATF family were systematically identified at the whole-genome level based on genomic and transcriptomic datasets, followed by analyses of their phylogenetic relationships, gene structures, and expression patterns. A total of six CREB/ATF family members were identified and classified into five subfamilies. Expression profiling and RT-qPCR validation revealed that most CREB/ATF genes were highly expressed in the mantle and displayed clear differences among shell-color phenotypes. Except for RpATF4 and RpCREBZF, most members exhibited relatively high expression levels in dark-colored shell strains, particularly in black and zebra-striped clams. Moreover, most genes showed low expression during early embryonic and larval stages but increased expression at the single-siphon spat and juvenile stages. These results suggest that the CREB/ATF family may be involved in melanin-associated shell-color regulation in R. philippinarum, providing important candidate genes and a theoretical basis for further elucidating the molecular mechanisms of shell-color formation in mollusks.