Changes in gene expression during development and thermogenesis in Arum

1999 ◽  
Vol 26 (5) ◽  
pp. 391 ◽  
Author(s):  
Stephen Chivasa ◽  
James O. Berry ◽  
Tom ap Rees ◽  
John P. Carr

Thermogenesis in Arum species is induced by salicylic acid (SA) and caused by activation of the alternative respiration pathway and the alternative oxidase (AOX), resulting in heat production. The enzymes phosphoenolpyruvate carboxylase (PEPCase) and NAD-dependent malic enzyme (NAD-ME) also show dramatic increases in activity during thermogenesis and are essential for heat generation. In this current study, we characterized the timing and localization of changes in levels of AOX, NAD-ME, and PEPCase polypeptide accumulation, and changes in Ppc and Me mRNA accumulation, in various Arum tissues during prethermogenic development and during thermogenesis. In addition, changes in ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) gene expression were analysed at the level of rbcL protein and mRNA accumulation. AOX, PEPCase, and NAD-ME all increased only in clubs during development, increasing 5–6-fold by the latest prethermogenic stage and remained at this level. The induction of thermogenesis did not cause any changes in levels of AOX, indicating that SA does not affect levels of the enzyme itself, but instead must act to stimulate activity. Reported increases in NAD-ME activity during club development correlated closely with mRNA and protein accumulation, whereas PEPCase activity appears to be determined by post-transcriptional and post-translational processes. Interestingly, Rubisco protein and mRNA were found in relatively abundant amounts in clubs during early developmental stages, and disappeared rapidly as the thermogenic enzymes began to increase in abundance. The induction of thermogenesis by a synthetic inducer of plant pathogen resistance, 2,6-dichloroisonicotinic acid, as well as the involvement of SA and AOX in both processes, reinforces evidence for a link between mechanisms controlling disease resistance in all plants and thermogenic induction in Arum.

1994 ◽  
Vol 72 (3-4) ◽  
pp. 78-83 ◽  
Author(s):  
Ricardo Escalante ◽  
Alberto García-Sáez ◽  
Maria-Asunción Ortega ◽  
Leandro Sastre

The steady-state levels of six different mRNAs have been studied during Artemia franciscana development. Some of these mRNAs are present in the cryptobiotic cyst, like those coding for cytoplasmic actins, sarcoplasmic/endoplasmic reticulum Ca2+-ATPase, and the Na+,K+-ATPase α-subunit isoform coded by the clone pArATNa136. The expression of these mRNAs is markedly induced during cyst development. A small increase in mRNA levels can be observed for some genes at very early stages of development (2 h). The main increase is observed between 4 and 16 h of development for all these genes, although the time course of mRNA accumulation is different for each one of the genes studied. Some other genes, like those coding for muscle actin (actin 3) or the Na+,K+-ATPase α-subunit isoform coded by the cDNA clone α2850, are not expressed in the cyst before resumption of development and their expression is induced after 10 or 6 h of development, respectively. These data on the kinetic of mRNA accumulation provide the information required to determine transcriptionally active developmental stages, necessary to study in more detail the mechanisms of transcriptional regulation during activation of cryptobiotic cysts and resumption of embryonic development.Key words: Artemia, gene expression, actin, Na,K-ATPase, Ca2+-ATPase.


Reproduction ◽  
2014 ◽  
Vol 147 (1) ◽  
pp. 53-64 ◽  
Author(s):  
Chubin Qin ◽  
Li Xu ◽  
Yalin Yang ◽  
Suxu He ◽  
Yingying Dai ◽  
...  

To increase the knowledge of probiotic effects on zebrafish (Danio rerio), we compare the effects of two probiotic strains, Lactobacillus rhamnosus CICC 6141 (a highly adhesive strain) and Lactobacillus casei BL23 (a weakly adhesive strain), on zebrafish reproduction and their offsprings' innate level of immunity to water-borne pathogens. During probiotics treatments from 7 to 28 days, both the Lactobacillus strains, and especially L. casei BL23, significantly increased fecundity in zebrafish: higher rates of egg ovulation, fertilization, and hatching were observed. Increased densities of both small and large vitellogenic follicles, seen in specimens fed either Lactobacillus strain, demonstrated accelerated oocyte maturation. Feeding either strain of Lactobacillus upregulated gene expression of leptin, kiss2, gnrh3, fsh, lh, lhcgr, and paqr8, which were regarded to enhance fecundity and encourage oocyte maturation. Concomitantly, the gene expression of bmp15 and tgfb1 was inhibited, which code for local factors that prevent oocyte maturation. The beneficial effects of the Lactobacillus strains on fecundity diminished after feeding of the probiotics was discontinued, even for the highly adhesive gut Lactobacillus strain. Administering L. rhamnosus CICC 6141 for 28 days was found to affect the innate immunity of offspring derived from their parents, as evinced by a lower level of alkaline phosphatase activity in early larval stages. This study highlights the effects of probiotics both upon the reproductive process and upon the offsprings' immunity during early developmental stages.


Mycologia ◽  
2011 ◽  
Vol 103 (2) ◽  
pp. 291-306 ◽  
Author(s):  
Suzanne Joneson ◽  
Daniele Armaleo ◽  
François Lutzoni

Reproduction ◽  
2010 ◽  
Vol 140 (6) ◽  
pp. 787-801 ◽  
Author(s):  
Claude Robert

The rise of the ‘omics’ technologies started nearly a decade ago and, among them, transcriptomics has been used successfully to contrast gene expression in mammalian oocytes and early embryos. The scarcity of biological material that early developmental stages provide is the prime reason why the field of transcriptomics is becoming more and more popular with reproductive biologists. The potential to amplify scarce mRNA samples and generate the necessary amounts of starting material enables the relative measurement of RNA abundance of thousands of candidates simultaneously. So far, microarrays have been the most commonly used high-throughput method in this field. Microarray platforms can be found in a wide variety of formats, from cDNA collections to long or short oligo probe sets. These platforms generate large amounts of data that require the integration of comparative RNA abundance values in the physiological context of early development for their full benefit to be appreciated. Unfortunately, significant discrepancies between datasets suggest that direct comparison between studies is difficult and often not possible. We have investigated the sample-handling steps leading to the generation of microarray data produced from prehatching embryo samples and have identified key steps that significantly impact the downstream results. This review provides a discussion on the best methods for the preparation of samples from early embryos for microarray analysis and focuses on the challenges that impede dataset comparisons from different platforms and the reasons why methodological benchmarking performed using somatic cells may not apply to the atypical nature of prehatching development.


2018 ◽  
Vol 92 (20) ◽  
Author(s):  
Michelle E. Olsen ◽  
Tessa N. Cressey ◽  
Elke Mühlberger ◽  
John H. Connor

ABSTRACTPolyamines and hypusinated eIF5A have been implicated in the replication of diverse viruses; however, defining their roles in supporting virus replication is still under investigation. We have previously reported that Ebola virus (EBOV) requires polyamines and hypusinated eIF5A for replication. Using a replication-deficient minigenome construct, we show that gene expression, in the absence of genome replication, requires hypusinated eIF5A. Additional experiments demonstrated that the block in gene expression upon hypusine depletion was posttranscriptional, as minigenome reporter mRNA transcribed by the EBOV polymerase accumulated normally in the presence of drug treatment where protein did not. When this mRNA was isolated from cells with low levels of hypusinated eIF5A and transfected into cells with normal eIF5A function, minigenome reporter protein accumulation was normal, demonstrating that the mRNA produced was functional but required hypusinated eIF5A function for translation. Our results support a mechanism in which hypusinated eIF5A is required for the translation, but not synthesis, of EBOV transcripts. In contrast, depletion of polyamines with difluoromethylornithine (DFMO) resulted in a strong block in the accumulation of EBOV polymerase-produced mRNA, indicating a different mechanism of polyamine suppression of EBOV gene expression. Supplementing with exogenous polyamines after DFMO treatment restored mRNA accumulation and luciferase activity. These data indicate that cellular polyamines are required for two distinct aspects of the EBOV life cycle. The bifunctional requirement for polyamines underscores the importance of these cellular metabolites in EBOV replication and suggests that repurposing existing inhibitors of this pathway could be an effective approach for EBOV therapeutics.IMPORTANCEEbola virus is a genetically simple virus that has a small number of proteins. Because of this, it requires host molecules and proteins to produce new infectious virus particles. Though attention is often focused on cellular proteins required for this process, it has recently been shown that cellular metabolites such as polyamines are also necessary for EBOV replication. Here we show that polyamines such as spermine and spermidine are required for the accumulation of EBOV mRNA and that eIF5A, a molecule modified by spermidine, is required for the translation, but not the production, of EBOV mRNAs. These findings suggest that effectively targeting this pathway could provide a biphasic block of EBOV replication.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Ishara Perera ◽  
Ayaka Fukushima ◽  
Tatsuki Akabane ◽  
Genki Horiguchi ◽  
Saman Seneweera ◽  
...  

Abstract Phytic acid (PA) is the primary phosphorus (P) storage compound in the seeds of cereals and legumes. Low PA crops, which are considered an effective way to improve grain nutrient availability and combat environmental issues relating to seed P have been developed using mutational and reverse genetics approaches. Here, we identify molecular mechanism regulating PA content among natural rice variants. First, we performed genome-wide association (GWA) mapping of world rice core collection (WRC) accessions to understand the genetic determinants underlying PA trait in rice. Further, a comparative study was undertaken to identify the differences in PA accumulation, protein profiles, and gene expression in low (WRC 5) and high PA (WRC 6) accessions. GWA results identified myo-inositol 3-phosphate synthase 1 (INO1) as being closely localized to a significant single nucleotide polymorphism. We found high rates of PA accumulation 10 days after flowering, and our results indicate that INO1 expression was significantly higher in WRC 6 than in WRC 5. Seed proteome assays found that the expression of INO1 was significantly higher in WRC 6. These results suggest that not only the gene itself but regulation of INO1 gene expression at early developmental stages is important in determining PA content in rice.


2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Aleksandra Dunislawska ◽  
Agata Szczerba ◽  
Maria Siwek ◽  
Marek Bednarczyk

Abstract Objective Regulation of gene expression during embryo development on the basis of migration of primordial germ cells (PGCs) in vivo has been rarely studied due to limited cell number and the necessity to isolate PGCs from a large number of embryos. Moreover, little is known about the comprehensive dynamics of the transcriptome in chicken PGCs during early developmental stages. The current study investigated transcriptome dynamics of chicken PGCs at key developmental stages: 4.5, 8 and 12 days of embryo incubation. PGCs were collected, and RNA was isolated using a commercial kit for single cells. The isolated RNA was subjected to microarray analysis (Agilent Technologies). Results Between 8 and 12 days of incubation, the highest number of genes was regulated. These data indicate that the most intense biological activity occurs between 8 and 12 days of embryo development. Heat map showed a significant decrease in gene expression on day 8, while it increased on day 12. The development of a precise method to isolate bird PGCs as well as the method to isolate RNA from single cells isolated from one embryo allows for early molecular analysis and detection of transcriptome changes during embryonic development.


2021 ◽  
Author(s):  
Jelisaveta Djordjevic ◽  
Zoé Dumas ◽  
Marc Robinson-Rechavi ◽  
Tanja Schwander ◽  
Darren James Parker

AbstractSexually dimorphic phenotypes are thought to arise primarily from sex-biased gene expression during development. Major changes in developmental strategies, such as the shift from hemimetabolous to holometabolous development, are therefore expected to have profound consequences for the dynamics of sex-biased gene expression. However, no studies have previously examined sex-biased gene expression over development in hemimetabolous insects, precluding comparisons between developmental strategies. Here we characterized sex-biased gene expression at three developmental stages in a hemimetabolous stick insect (Timema californicum): hatchlings, juveniles, and adults. As expected, the proportion of sex-biased genes gradually increased over development. Sex-biased genes identified at early developmental stages were generally consistently male- or female-biased at later stages, suggesting their importance in sexual differentiation. We then compared the dynamics of sex-biased gene expression over development in T. californicum to those of the holometabolous fly Drosophila melanogaster by reanalyzing publicly available RNA-seq data from third instar larval, pupal and adult stages. In D. melanogaster, sex-biased gene expression increases abruptly at the adult stage when morphological sexual dimorphism is manifested. This supports the prediction that sex-biased gene expression mirrors phenotypic sexual dimorphism. Our study details for the first time the dynamics of sex-biased gene expression over development in a hemimetabolous insect and suggests that these dynamics differ extensively between holometabolous and hemimetabolous species.


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