Chromatin diminution is strictly correlated to somatic cell behavior in early development of the nematode Parascaris univalens

1995 ◽  
Vol 108 (6) ◽  
pp. 2393-2404
Author(s):  
M.R. Esteban ◽  
G. Giovinazzo ◽  
C. Goday
Keyword(s):  
Somatic Cell ◽  
Early Development ◽  
Cytochalasin B ◽  
Developmental Stages ◽  
Cell Behavior ◽  
Chromatin Diminution ◽  
Developmental Behavior ◽  
Licl Treatment ◽  
The Relationship ◽  
Early Developmental

We have studied the relationship between the occurrence of chromatin diminution and the developmental behavior of somatic blastomeres in early development of the nematode Parascaris univalens. A cytological and immunocytochemical analysis of chromatin diminution was performed in P. univalens embryos exposed to ‘vegetalizing’ (LiCl) and ‘animalizing’ (NaSCN) substances during early developmental stages. We have also analyzed chromatin diminution in embryos displaying only symmetrical ‘somatic-like’ divisions due to a brief cytochalasin B treatment at the pronuclear stage. The results show that LiCl treatment induces chromatin diminution in P0-P4 pregerminal blastomeres while NaSCN treatment prevents it. Pregerminal cells undergoing chromatin diminution in ‘vegetalized’ embryos behaved like somatic cells with respect to division and cleavage patterns. NaSCN treatment results in undiminuted polynucleated embryos that are not capable of cleavage. In cytochalasin B-pulsed embryos, chromatin diminution occurs in all blastomeres. From our results we conclude that chromatin diminution and somatic cell behavior are not separable and constitute strictly correlated events in Parascaris. Moreover, the results indicate that the segregation of the cytoplasmic factors involved in chromatin diminution in early Parascaris development are microfilament-mediated. Here, we also report the formation of a latter pregerminal cell precursor (P5) not susceptible to LiCl-induced chromatin diminution.

scholarly journals Energetic constraints on an early developmental stage: a comparative view

2007 ◽  
Vol 4 (1) ◽  
pp. 123-126 ◽  
Author(s):  
James F Gillooly ◽  
Gustavo A Londoño ◽  
Andrew P Allen
Keyword(s):  
Metabolic Rate ◽  
Developmental Stage ◽  
Developmental Stages ◽  
The Body ◽  
Early Developmental Stage ◽  
Time Required ◽  
Taxonomic Groups ◽  
Relationship Of ◽  
The Relationship ◽  
Early Developmental

Biologists have long sought a means by which to quantify similarities and differences in embryonic development across species. Here we present a quantitative approach for predicting the timing of developmental events based on principles of allometry and biochemical kinetics. Data from diverse oviparous species support model predictions that most variation in the time required to reach one early developmental stage—the time to first heartbeat—is explained by the body size and temperature dependence of metabolic rate. Furthermore, comparisons of this stage with later developmental stages suggest that, after correcting for size and temperature, the relationship of metabolic rate to the rate of embryogenesis is approximately invariant across taxonomic groups and stages of ontogeny.

scholarly journals Microarray analysis of gene expression during early development: a cautionary overview

Reproduction ◽  
2010 ◽  
Vol 140 (6) ◽  
pp. 787-801 ◽  
Author(s):  
Claude Robert
Keyword(s):  
Gene Expression ◽  
Early Development ◽  
Microarray Analysis ◽  
Developmental Stages ◽  
Sample Handling ◽  
Early Embryos ◽  
High Throughput Method ◽  
Full Benefit ◽  
Key Steps ◽  
Early Developmental

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.

Programming of gastrulation during the second cleavage cycle in Limnaea stagnalis: a study with lithium chloride and actinomycin D

Development ◽  
1967 ◽  
Vol 17 (2) ◽  
pp. 367-374
Author(s):  
W. L. M. Geilenkirchen
Keyword(s):  
Mitotic Cycle ◽  
Developmental Stages ◽  
Continuous Treatment ◽  
Egg Cell ◽  
Rate Of Oxygen Consumption ◽  
Licl Treatment ◽  
Treatment Changes ◽  
Limnaea Stagnalis ◽  
Early Developmental ◽  
Periodic Changes

It is well known that treatment with LiCl can cause abnormal embryonic development, but its mode of action is still uncertain (Gustafson, 1954; Geilenkirchen, 1961; Lallier, 1964). It also remains to be shown whether LiCl enters the egg cell at early developmental stages and acts internally, or does not penetrate into the cell and is active only at the outer surface (Elbers, 1959). LiCl treatment changes the rate of oxygen uptake during the early cleavage cycles in Limnaea. The rate of oxygen consumption varies between the first and the third cleavage in a cyclic fashion with maxima at mitotic prophases (Geilenkirchen, 1961). Continuous treatment with LiCl disturbs the pattern of periodic changes in the rate of uptake (Fig. 2). The influence of LiCl, however, is not the same at all times. It does not start until shortly before prophase of the second mitotic cycle, and this may indicate that until prophase of the second division no processes in which LiCl interferes occur.

Development of pigment-cup eyes in the polychaetePlatynereis dumeriliiand evolutionary conservation of larval eyes in Bilateria

Development ◽  
2002 ◽  
Vol 129 (5) ◽  
pp. 1143-1154 ◽  
Author(s):  
Detlev Arendt ◽  
Kristin Tessmar ◽  
Maria-Ines Medeiros de Campos-Baptista ◽  
Adriaan Dorresteijn ◽  
Joachim Wittbrodt
Keyword(s):  
Visual System ◽  
Early Development ◽  
Developmental Stages ◽  
Photoreceptor Cells ◽  
Evolutionary Conservation ◽  
Early Developmental Stages ◽  
Platynereis Dumerilii ◽  
Differentiation Marker ◽  
Early Developmental

The role of Pax6 in eye development in insects and vertebrates supports the view that their eyes evolved from simple pigment-cup ocelli present in their last common ancestors (Urbilateria). The cerebral eyes in errant polychaetes represent prototype invertebrate pigment-cup ocelli and thus resemble the presumed ancestral eyes. We have analysed expression of conserved eye specification genes in the early development of larval and adult pigment-cup eyes in Platynereis dumerilii (Polychaeta, Annelida, Lophotrochozoa). Both larval and adult eyes form in close vicinity of the optic anlagen on both sides of the developing brain ganglia. While pax6 is expressed in the larval, but not in the developing, adult eyes, expression of six1/2 from trochophora stages onwards specifically outlines the optic anlagen and thus covers both the developing larval and adult eyes. Using Platynereis rhabdomeric opsin as differentiation marker, we show that the first pair of adult eye photoreceptor cells is detected within bilateral clusters that transitorily express ath, the Platynereis atonal orthologue, thus resembling proneural sensory clusters. Our data indicate that – similar to insects, but different from the vertebrates – polychaete six1/2 expression outlines the entire visual system from early developmental stages onwards and ath-positive clusters generate the first photoreceptor cells to appear. We propose that pax6-, six1/2- and ath-positive larval eyes, as found in today’s trochophora, were present already in Urbilateria.

scholarly journals Zebrafish lipid droplets regulate embryonic ATP homeostasis to power early development

Open Biology ◽  
2017 ◽  
Vol 7 (7) ◽  
pp. 170063 ◽  
Author(s):  
Asmita Dutta ◽  
Deepak Kumar Sinha
Keyword(s):  
Fatty Acids ◽  
Early Development ◽  
Lipid Droplets ◽  
Developmental Stages ◽  
Fatty Acyl ◽  
Zebrafish Embryos ◽  
Early Developmental Stages ◽  
Successful Execution ◽  
Acyl Coenzyme A ◽  
Early Developmental

In zebrafish embryos, the maternally supplied pool of ATP is insufficient to power even the earliest of developmental events (0–3 hpf) such as oocyte-to-embryo transition (OET). The embryos generate an additional pulse (2.5 h long) of ATP (1.25–4 hpf) to achieve the embryonic ATP homeostasis. We demonstrate that the additional pulse of ATP is needed for successful execution of OET. The maternally supplied yolk lipids play a crucial role in maintaining the embryonic ATP homeostasis. In this paper, we identify the source and trafficking routes of free fatty acids (FFAs) that feed the mitochondria for synthesis of ATP. Interestingly, neither the maternally supplied pool of yolk-FFA nor the yolk-FACoA (fatty acyl coenzyme A) is used for ATP homeostasis during 0–5 hpf in zebrafish embryos. With the help of lipidomics, we explore the link between lipid droplet (LD)-mediated lipolysis and ATP homeostasis in zebrafish embryos. Until 5 hpf, the embryonic LDs undergo extensive lipolysis that generates FFAs. We demonstrate that these newly synthesized FFAs from LDs are involved in the maintenance of embryonic ATP homeostasis, rather than the FFAs/FACoA present in the yolk. Thus, the LDs are vital embryonic organelles that maintain the ATP homeostasis during early developmental stages (0–5 hpf) in zebrafish embryos. Our study highlights the important roles carried on by the LDs during the early development of the zebrafish embryos.

scholarly journals Floral organogenesis in Urophysa rockii, a rediscovered endangered and rare species of Ranunculaceae

Botany ◽  
2016 ◽  
Vol 94 (3) ◽  
pp. 215-224 ◽  
Author(s):  
Liang Zhao ◽  
Jing-zhi Gong ◽  
Xiao-hui Zhang ◽  
You-quan Liu ◽  
Xiao Ma ◽  
...  
Keyword(s):  
Floral Development ◽  
Developmental Stages ◽  
Sequence Data ◽  
Molecular Data ◽  
Floral Organogenesis ◽  
Dna Sequence Data ◽  
Mature Ovule ◽  
Floral Phyllotaxis ◽  
The Relationship ◽  
Early Developmental

Urophysa is an Asian endemic genus in the Ranunculaceae, but data on floral organogenesis, which would be a useful complement to molecular data in clarifying the relationship with closely related taxa (Aquilegia and Semiaquilegia) in Ranunculaceae, are completely lacking. We used scanning electron microscopy and light microscopy to study the floral development of Urophysa rockii Ulbrich, a recently rediscovered species in this genus. The sepals are initiated spirally, whereas other organs are nonsimultaneously whorled; the floral phyllotaxis is whorled. Primordia of the sepals are lunular and truncate, but those of the petals and stamens are hemispherical and rounded. After sepal initiation, there is a delay in development, but the initiation of petals and stamens is continuous. The developmental sequence of the microspores in the stamens is centrifugal, although the stamens are initiated centripetally. The early developmental stages of the staminodes are similar to those of the stamens, although much smaller, so they may be phylogenetically homologous organs. The carpel primordia are lunular in shape and plicate. The mature ovule is anatropous and bitegmic. Urophysa shows similar floral development features as Aquilegia and Semiaquilegia, although with some differences, which supports the relationship inferred by DNA sequence data.

scholarly journals Early development of Hypogymnia physodes (L.) Nyl. in response to emissions from a copper smelter

2001 ◽  
Vol 33 (6) ◽  
pp. 527-538 ◽  
Author(s):  
Irina N. Mikhailova ◽  
Christoph Scheidegger
Keyword(s):  
Early Development ◽  
Developmental Stages ◽  
Developmental Rate ◽  
Copper Smelter ◽  
Copper Smelting ◽  
Hypogymnia Physodes ◽  
Toxic Impact ◽  
Early Developmental ◽  
Desert Zone ◽  
Copper Smelting Plant

AbstractThe early development of Hypogymnia physodes from soredia to the formation of stratified lobes has been studied experimentally in the vicinity of a copper-smelting plant in theMiddle Urals. SEM investigations combined with life table analyses of early developmental stages revealed decreases in soredial survival and developmental rate in polluted localities. Non-stricatified pre-thallus stages without an epicortex were tolerant to toxic impact and were able to survive even in the zone with the highest pollution (lichen desert zone). The sensitivity of developmental stagesancreased after stratified lobes had developed.

scholarly journals Stage-Specific Effects of Ionizing Radiation during Early Development

2020 ◽  
Vol 21 (11) ◽  
pp. 3975 ◽  
Author(s):  
Yasuko Honjo ◽  
Tatsuo Ichinohe
Keyword(s):  
Ionizing Radiation ◽  
Early Development ◽  
Molecular Mechanisms ◽  
Developmental Stages ◽  
Embryonic Cells ◽  
Specific Effects ◽  
Early Developmental Stages ◽  
Similarities And Differences ◽  
Radio Sensitivity ◽  
Early Developmental

Early embryonic cells are sensitive to genotoxic stressors such as ionizing radiation. However, sensitivity to these stressors varies depending on the embryonic stage. Recently, the sensitivity and response to ionizing radiation were found to differ during the preimplantation period. The cellular and molecular mechanisms underlying the change during this period are beginning to be elucidated. In this review, we focus on the changes in radio-sensitivity and responses to ionizing radiation during the early developmental stages of the preimplantation (before gastrulation) period in mammals, Xenopus, and fish. Furthermore, we discuss the underlying cellular and molecular mechanisms and the similarities and differences between species.

scholarly journals Cortical-nuclear interactions in cephalopod development: cytochalasin B effects on the informational pattern in the cell surface

Development ◽  
1974 ◽  
Vol 31 (1) ◽  
pp. 1-25
Author(s):  
John M. Arnold ◽  
Lois D. Williams-Arnold
Keyword(s):  
Cytochalasin B ◽  
Developmental Stages ◽  
Early Cleavage ◽  
Organ Differentiation ◽  
Asymmetrical Pattern ◽  
Clear Cytoplasm ◽  
Weak Surface ◽  
Loligo Pealei ◽  
Early Developmental ◽  
Low Dosage

Cytochalasin B (CB) was applied to early developmental stages of the egg of the squid Loligo pealei and defects in cleavage and/or organogenesis were produced. If CB was applied in relatively high dosages (2·0 μg/ml) or for long periods (30 min) to embryos in early cleavage the existing furrows irreversibly disappeared. If precleavage embryos were similarly treated the streaming pattern which forms the blastodisc was interrupted and patches of clear cytoplasm appeared on the zygote surface. Short low dosage pulses (0·2 μg/ml for 10 min) produced cleavage effects correlated with the time of pulsing. If pulsed within 30 min of first cleavage the first furrow did not appear in the majority of cases but the second furrow appeared synchronously with the controls and appeared normal in all respects. If pulsed approximately 30 min or longer before cleavage the first furrow usually appeared on time as a weak surface line. Second cleavage appeared normally. However, the asymmetrical pattern of third cleavage was ‘equalized’ and the blastomeres tended to be of equal size. It was concluded that there are subtle cytoplasmic movement patterns, sensitive to CB, which position the nuclei before each cleavage and thereby determine the cleavage pattern. If embryos were pulsed (0·2 μg/ml for 10 min) at various times during early development, anomalies in differentiation at organogenesis (3–4 days later) were produced which correlated with the time of pulsing. Pulses after germinal layer formation (stage 11) produced no noticeable effects and pulses before the cytoplasmic streaming which produces the blastodisc similarly had very little or no effect. However, pulses during blastodisc formation or early cleavage produced severely affected embryos in which organ displacement, poor tissue and organ differentiation, or organ deficiencies were common. Pulsed embryos were scored and the time of pulsing correlated with the severity of effects. The nuclei of the inductive yolk epithelium were abnormal, frequently being rounded, clumped and/or containing clumped or abnormally diffuse chromatin. It was concluded that the streaming pattern which forms the blastodisc in some way fixes or enhances a pre-existing pattern of developmental information which resides in or at the surface of the egg. Once this pattern is established it is insensitive to CB but it can still be demonstrated by other techniques. This informational pattern apparently influences the nuclei of the yolk epithelium that come to lie in specific regions and controls the expression of their genome so that specific organs are programmed.

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