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PloS One 2011The plant cell walls play an important role in somatic embryogenesis and plant development. Pectins are major chemical components of primary cell walls while...
BACKGROUND
The plant cell walls play an important role in somatic embryogenesis and plant development. Pectins are major chemical components of primary cell walls while homogalacturonan (HG) is the most abundant pectin polysaccharide. Developmental regulation of HG methyl-esterification degree is important for cell adhesion, division and expansion, and in general for proper organ and plant development.
METHODOLOGY/PRINCIPAL FINDINGS
Developmental localization of pectic homogalacturonan (HG) epitopes and the (1→4)-β-D-galactan epitope of rhamnogalacturonan I (RG-I) and degree of pectin methyl-esterification (DM) were studied during somatic embryogenesis of banana (Musa spp. AAA). Histological analysis documented all major developmental stages including embryogenic cells (ECs), pre-globular, globular, pear-shaped and cotyledonary somatic embryos. Histochemical staining of extracellularly secreted pectins with ruthenium red showed the most intense staining at the surface of pre-globular, globular and pear-shaped somatic embryos. Biochemical analysis revealed developmental regulation of galacturonic acid content and DM in diverse embryogenic stages. Immunodots and immunolabeling on tissue sections revealed developmental regulation of highly methyl-esterified HG epitopes recognized by JIM7 and LM20 antibodies during somatic embryogenesis. Cell walls of pre-globular/globular and late-stage embryos contained both low methyl-esterified HG epitopes as well as partially and highly methyl-esterified ones. Extracellular matrix which covered surface of early developing embryos contained pectin epitopes recognized by 2F4, LM18, JIM5, JIM7 and LM5 antibodies. De-esterification of cell wall pectins by NaOH caused a decrease or an elimination of immunolabeling in the case of highly methyl-esterified HG epitopes. However, immunolabeling of some low methyl-esterified epitopes appeared stronger after this base treatment.
CONCLUSIONS/SIGNIFICANCE
These data suggest that both low- and highly-methyl-esterified HG epitopes are developmentally regulated in diverse embryogenic stages during somatic embryogenesis. This study provides new information about pectin composition, HG methyl-esterification and developmental localization of pectin epitopes during somatic embryogenesis of banana.
Topics: Cells, Cultured; Epitopes; Gene Expression Regulation, Plant; Musa; Pectins
PubMed: 21826225
DOI: 10.1371/journal.pone.0022992 -
Poultry Science Oct 2019Embryo development and chick quality are influenced by parental genotype, age, nutrition, environment, and flock management. The aim of study was to determine if...
Embryo development and chick quality are influenced by parental genotype, age, nutrition, environment, and flock management. The aim of study was to determine if genotype, age of goose or eggs laid near the onset of egg production vs. eggs laid near the end of reproduction influence the stage of embryo at oviposition. Three experiments were undertaken. To compare genotypes (Experiment 1) 150 eggs were collected from 3-year-old commercial line White Koluda (WK) geese and from two breeds involved in a genetic resources conservation program, Zatorska (Za) and Bilgoraj (Bi). Age comparison (Experiment 2) was conducted with 200 eggs collected from 1-, 2-, 3-, and 4-year-old WK geese. To compare laying periods (Experiment 3), 150 WK eggs were collected at the first week of March and 100 at the second half of June. Eggs were stored for 72 h at 16°C, staged using Eyal-Giladi and Kochav (EGK, Roman numerals) and Hamburger and Hamilton (HH, Arabic numerals) procedures. Experiment 1: Individual breed differences were evident with Stage X EGK embryos comprising 42.4, 33.3, and 38.7% in the eggs examined from the WK, Bi, and Za, respectively. For all breeds combined, 38.8% of the embryos were in Stage X, but in the next order in WK there was stage XI (18.2%), while in geese from the genetic reserve it was stage XIII (Bi - 33.3; Za - 29.0%). Experiment 2: In eggs of 1-, 2-, and 3-year-old WK geese, the majority of embryos (38.7, 32.4 and 42.2%, respectively) were in Stage X. In contrast, in 4-year-old geese the embryos were in Stage XI (36.1%). Experiment 3: In eggs collected in March and in June most of embryos were in Stage X (33.7% and 43.6%, respectively). In addition, more developmentally advanced stages (XI-XIII) were similar in both periods. However, embryos in Stage 2 HH were only observed in eggs collected at the end of laying season. Interestingly, earlier stages (VI-IX) were observed exclusively in the eggs collected in March.
Topics: Age Factors; Animals; Embryo, Nonmammalian; Embryonic Development; Geese; Genotype; Oviposition; Reproduction; Time Factors
PubMed: 31073603
DOI: 10.3382/ps/pez225 -
Poultry Science Dec 2017The pioneering study of Eyal-Giladi and Kochav (EG&K; Eyal-Giladi and Kochav, 1976) on the early developmental stages-from fertilization, through oviposition, to the...
The pioneering study of Eyal-Giladi and Kochav (EG&K; Eyal-Giladi and Kochav, 1976) on the early developmental stages-from fertilization, through oviposition, to the gastrulation process-set the standard for characterizing chicken embryos, and has been used in numerous studies over the years. During uterine development, the chicken embryo undergoes dramatic changes, extremely rapid cell cycles, massive cell death, and axial determination processes. However, once the egg is laid, the temperature drops and the embryo enters into a diapause-like state. This phenomenon is utilized to store fertile eggs prior to incubation. The ability to resume development to hatching, following storage, relies on several factors, including the number of living cells and the embryonic developmental stage. These factors are highly influenced by the storage conditions-mainly duration and temperature. Thus, to study the effects of storage conditions on embryonic viability, a comprehensive characterization of the starting point-shortly after oviposition-is needed. In this study, we characterized freshly laid broiler eggs from Ross 308 flocks for embryonic developmental stage, total cell count, and cell viability. Using the novel high-resolution episcopic microscopy (HREM) system, we show, for the first time, high-resolution 3D morphological models of blastoderms which allow for highly accurate embryonic staging. Staging was also done under a dissecting microscope thus allowing for a direct side-by-side comparison of the two methods. Analysis of freshly laid blastomeres showed that the total nucleus count increases with developmental stage from ∼60,000 at stage X EG&K to ∼130,000 at stage XIII EG&K, whereas the proportion of mitotic index and dying cells at oviposition are ∼2% and ∼5%, respectively. Moreover, staging embryos from young and old flocks revealed that the blastoderms of the old flocks are more developed. Specifically, the predominant embryonic stages were XI and XII EG&K in young and old flocks, respectively. Collectively, we characterized parameters that can serve to analyze the maladaptive effects of prolonged storage under various conditions on embryo survival.
Topics: Animal Husbandry; Animals; Blastoderm; Cell Count; Cell Survival; Chick Embryo; Chickens; Embryology; Mitotic Index; Ovum
PubMed: 29053871
DOI: 10.3382/ps/pex242 -
Molecular and Cellular Biology Oct 2015Eukaryotic gene expression is often controlled by distant regulatory elements. In developing B lymphocytes, transcription is associated with V(D)J recombination at...
Eukaryotic gene expression is often controlled by distant regulatory elements. In developing B lymphocytes, transcription is associated with V(D)J recombination at immunoglobulin loci. This process is regulated by remote cis-acting elements. At the immunoglobulin heavy chain (IgH) locus, the 3' regulatory region (3'RR) promotes transcription in mature B cells. This led to the notion that the 3'RR orchestrates the IgH locus activity at late stages of B cell maturation only. However, long-range interactions involving the 3'RR were detected in early B cells, but the functional consequences of these interactions were unknown. Here we show that not only does the 3'RR affect transcription at distant sites within the IgH variable region but also it conveys a transcriptional silencing activity on both sense and antisense transcription. The 3'RR-mediated silencing activity is switched off upon completion of VH-DJH recombination. Our findings reveal a developmentally controlled, stage-dependent shift in the transcriptional activity of a master regulatory element.
Topics: Animals; Gene Expression Regulation, Developmental; Immunoglobulin Heavy Chains; Mice, 129 Strain; Mice, Transgenic; Regulatory Elements, Transcriptional; Transcription, Genetic; V(D)J Recombination
PubMed: 26195822
DOI: 10.1128/MCB.00509-15 -
Developmental Biology Mar 1989Changes in energy metabolism during larval development in Caenorhabditis elegans have been investigated using phosphorus nuclear magnetic resonance (31P NMR). The...
Changes in energy metabolism during larval development in Caenorhabditis elegans have been investigated using phosphorus nuclear magnetic resonance (31P NMR). The relative concentrations of ATP, ADP, AMP, sugar phosphates, and other metabolites were observed to change during larval development, producing stage-specific spectra. These spectra are consistent with enzyme assays for isocitrate dehydrogenase and isocitrate lyase, indicating that high activity of the glyoxylate pathway during embryonic development decreases during the first larval (L1) stage, and respiration during the L2, L3, and L4 stages occurs preferentially through the TCA cycle. Metabolic strategies were further studied using mutants that are predisposed to enter the dauer stage, a developmentally arrested third-stage larva formed under conditions of overcrowding and limited food. After the L1 molt, energy metabolism in animals destined to become dauer larvae diverges from that of animals committed to growth. Relative to the L1, the L2 larvae committed to growth exhibit increased isocitrate dehydrogenase activity as well as increases in ATP and other high-energy phosphates, but predauer (L2d) larvae exhibit declining enzyme activities and declining levels of high-energy phosphates. The predominant phosphorus NMR signal in dauer larva extracts corresponds to inorganic phosphate. We conclude that metabolism is regulated during C. elegans larval development, with a major transition apparent after the L1 stage. This transition does not occur in larvae destined to form dauer larvae.
Topics: Adenine Nucleotides; Animals; Caenorhabditis; Energy Metabolism; Isocitrate Dehydrogenase; Isocitrate Lyase; Larva; Magnetic Resonance Spectroscopy
PubMed: 2917691
DOI: 10.1016/0012-1606(89)90214-5 -
Aquatic Toxicology (Amsterdam,... Dec 2009Bifenthrin (BF) is widely used as a miticide in orchards, nurseries and homes due to its great photostability and insecticidal activity. Recently, extensive research has...
Bifenthrin (BF) is widely used as a miticide in orchards, nurseries and homes due to its great photostability and insecticidal activity. Recently, extensive research has been conducted on the toxicity of BF in in vitro and in vivo assays. However, no data is so far available regarding the developmental toxicity of BF to fish in early life stages. In this study, the developmental effects of BF were evaluated in embryo-larval zebrafish. At specified stages (24, 48, 72, and 96hpf), spontaneous movement, survival and hatching as well as non-lethal malformation like curved body axis or edema were described in detail. No significant lethal effects of the treatment group compared to the control occurred except for the highest concentration group exposed for 96h. The hatching process was accelerated by BF in a concentration-dependent way, correlated with increasing spontaneous movement. Developmental abnormalities were observed for the test compound with 96-h EC(50) of 256microgL(-1) for pericardial edema, and 109microgL(-1) for curved body axis. Results from locomotor assays showed that zebrafish larvae of 96hpf exhibited impaired swimming behaviour after exposure to 50, 100, and 200microgL(-1) from 3 to 84hpf. After being cultured in the BF-free embryo medium for one more day till 120hpf, larvae from the 50microgL(-1)group seemed to have recovered and showed no difference in the swimming behaviour compared to the control while animals of the two higher concentration groups were exhausted and swam in significantly lower speed. Furthermore, reverse transcription real-time PCR results showed that vitellogenin I expressions were significantly induced in larval zebrafish exposed to 150microgL(-1) BF for 72h, indicating the disruption of the endocrine level. In summary, our studies showed that BF was developmentally toxic to zebrafish in early life stage after short-term exposure to sublethal concentrations and had the ability to impair the individual behaviours which are of great importance in the assessment of their ecological fitness.
Topics: Acaricides; Animals; Embryo, Nonmammalian; Larva; Motor Activity; Pyrethrins; Toxicity Tests; Vitellogenins; Water Pollutants, Chemical; Zebrafish
PubMed: 19880199
DOI: 10.1016/j.aquatox.2009.10.003 -
Wiley Interdisciplinary Reviews.... 2013Developmentally regulated genes are often controlled by distant enhancers, silencers and insulators, to implement their correct transcriptional programs. In recent... (Review)
Review
Developmentally regulated genes are often controlled by distant enhancers, silencers and insulators, to implement their correct transcriptional programs. In recent years, the development of 3C and derived techniques (4C, 5C, HiC, ChIA-PET, etc.) has confirmed that chromatin looping is an important mechanism for the transfer of regulatory information in mammalian cells. At many developmentally regulated gene loci, transcriptional activation is indeed accompanied by the formation of chromatin loops between genes and distant enhancers. Similarly, dynamic looping between insulator elements and changes in local 3D organization may be observed upon variation in transcriptional activity. Chromatin looping also occurs at silent gene loci, where its function remains less understood. In lineage-committed cells, partial 3D configurations are detected at loci that are activated at later stages. However, these partial configurations usually lack promoter-enhancer loops that accompany transcriptional activation, suggesting they have structural functions. Definitive evidence for a repressive role of chromatin looping is still lacking. Chromatin loops have been reported at repressed loci but, alternatively, they may act as a distraction for active loops. Together, these mechanisms allow fine-tuning of regulatory programs, thus providing further diversity in the transcriptional control of developmentally regulated gene loci.
Topics: Animals; Chromatin; Chromatin Assembly and Disassembly; Gene Expression Regulation, Developmental; Genes, Developmental; Genetic Loci; Humans
PubMed: 24014450
DOI: 10.1002/wdev.103 -
Frontiers in Cellular Neuroscience 2014Rett Syndrome (RTT) is a neurodevelopmental disorder associated with intellectual disability, mainly caused by loss-of-function mutations in the MECP2 gene. RTT brains...
Rett Syndrome (RTT) is a neurodevelopmental disorder associated with intellectual disability, mainly caused by loss-of-function mutations in the MECP2 gene. RTT brains display decreased neuronal size and dendritic arborization possibly caused by either a developmental failure or a deficit in the maintenance of dendritic arbor structure. To distinguish between these two hypotheses, the development of Mecp2-knockout mouse hippocampal neurons was analyzed in vitro. Since a staging system for the in vitro development of mouse neurons was lacking, mouse and rat hippocampal neurons development was compared between 1-15 days in vitro (DIV) leading to a 6-stage model for both species. Mecp2-knockout hippocampal neurons displayed reduced growth of dendritic branches from stage 4 (DIV4) onwards. At stages 5-6 (DIV9-15), synapse number was lowered in Mecp2-knockout neurons, suggesting increased synapse elimination. These results point to both a developmental and a maintenance setback affecting the final shape and function of neurons in RTT.
PubMed: 24550777
DOI: 10.3389/fncel.2014.00018 -
The Journal of Experimental Zoology Oct 1986A comparative developmental analysis was made of lipids from wild-type and adipose60 (adp60) mutants of Drosophila melanogaster. The lipid content and fatty acid... (Comparative Study)
Comparative Study
A comparative developmental analysis was made of lipids from wild-type and adipose60 (adp60) mutants of Drosophila melanogaster. The lipid content and fatty acid profiles of late third instar larvae, pupae, and mature adults were characterized in methanol:chloroform extracts utilizing thin layer and gas-liquid chromatography. Total lipid content of mutant adults was approximately twice that of the wild-type, but no genotypic differences in lipid content were seen in earlier developmental stages. No sexual dimorphism was observed in total lipid content, although fatty acid profiles revealed some sexual differences. Many stage-specific differences in fatty acid profiles and lipid content were developmentally associated with each genotype. Mutants tended to retain the larval phenotype in lipid content and, to a lesser extent, in fatty acid profile. In comparison to wild-type, mutants tended to have increased lipid saturation, especially in 16-carbon fatty acids in mature adults and in 18:0 fatty acids in late larvae and pupae. No significant difference between the mutants and wild-type appeared in the developmental profiles for 14:1 fatty acid isomers. Hence, adp60 does not alter the desaturation-elongation pathway, a secondary pathway for fatty acid desaturation in Drosophila, which received support from this analysis.
Topics: Animals; Chromatography, Gas; Chromatography, Thin Layer; Drosophila melanogaster; Fatty Acids; Female; Larva; Lipids; Male; Mutation; Pupa; Sex Characteristics
PubMed: 3095486
DOI: 10.1002/jez.1402400112 -
Histochemistry and Cell Biology Jan 2005Peroxisome proliferator-activated receptors (PPARs) are members of the superfamily of nuclear hormone receptors involved in embryo development and differentiation of...
Peroxisome proliferator-activated receptors (PPARs) are members of the superfamily of nuclear hormone receptors involved in embryo development and differentiation of several tissues in mammals. The aim of the present study was to investigate the possible differential expression of the three PPAR subtypes (PPARalpha, PPARbeta, and PPARgamma) in relation to gender and developmental stage in zebrafish. For this purpose PPAR expression was assessed by immunohistochemistry in 7-day-old larvae, 1-month-old juveniles, and 1-year-old adults. Additionally, the activity of peroxisomal acyl-CoA oxidase (AOX), a gene regulated by PPARs, and the volume density of catalase-immunolabeled liver peroxisomes (V(VP)) was examined. No significant gender-related differences were detected in the tissue distribution of the three PPAR subtypes or in peroxisomal AOX activity and V(VP). The percentage of PPARbeta-positive hepatocytes was significantly higher in females than in males suggesting a specific regulatory role of this subtype in female zebrafish. The three PPAR subtypes were already expressed at the larval stage, with a similar tissue distribution pattern to that found in adults. For all stages, PPARalpha and PPARgamma were expressed at higher levels than PPARbeta, and PPARbeta immunolabeling was stronger in juveniles than in larval or adult stages. The percentages of hepatocyte nuclei immunolabeled for PPARs was higher in early developmental stages than in adults, similarly to AOX activity and V(VP). In conclusion, our results indicate that PPAR expression, the activity of its target gene AOX, and peroxisomal biogenesis are developmentally modulated in zebrafish.
Topics: Acyl-CoA Oxidase; Age Factors; Animals; Blotting, Western; Cell Nucleus; Embryo, Nonmammalian; Female; Hepatocytes; Immunohistochemistry; Male; Organ Specificity; Oxidoreductases; PPAR alpha; PPAR gamma; PPAR-beta; Peroxisome Proliferator-Activated Receptors; Peroxisomes; Sex Factors; Zebrafish
PubMed: 15616845
DOI: 10.1007/s00418-004-0737-2