scholarly journals Direct cell lineage analysis in Drosophila melanogaster by time-lapse, three-dimensional optical microscopy of living embryos.

1989 ◽  
Vol 109 (2) ◽  
pp. 505-516 ◽  
Author(s):  
J S Minden ◽  
D A Agard ◽  
J W Sedat ◽  
B M Alberts
Keyword(s):  
Drosophila Melanogaster ◽  
Three Dimensional ◽  
Cell Lineage ◽  
Time Lapse ◽  
Small Region ◽  
Early Embryo ◽  
Nuclear Cycle ◽  
Cell Position ◽  
History Of ◽  
Direct Cell

One of the first signs of cell differentiation in the Drosophila melanogaster embryo occurs 3 h after fertilization, when discrete groups of cells enter their fourteenth mitosis in a spatially and temporally patterned manner creating mitotic domains (Foe, V. E. and G. M. Odell, 1989, Am. Zool. 29:617-652). To determine whether cell residency in a mitotic domain is determined solely by cell position in this early embryo, or whether cell lineage also has a role, we have developed a technique for directly analyzing the behavior of nuclei in living embryos. By microinjecting fluorescently labeled histones into the syncytial embryo, the movements and divisions of each nucleus were recorded without perturbing development by using a microscope equipped with a high resolution, charge-coupled device. Two types of developmental maps were generated from three-dimensional time-lapse recordings: one traced the lineage history of each nucleus from nuclear cycle 11 through nuclear cycle 14 in a small region of the embryo; the other recorded nuclear fate according to the timing and pattern of the 14th nuclear division. By comparing these lineage and fate maps for two embryos, we conclude that, at least for the examined area, the pattern of mitotic domain formation in Drosophila is determined by the position of each cell, with no effect of cell lineage.

scholarly journals Oxygen changes drive non-uniform scaling in Drosophila melanogaster embryogenesis

F1000Research ◽  
2015 ◽  
Vol 4 ◽  
pp. 1102 ◽  
Author(s):  
Steven G. Kuntz ◽  
Michael B. Eisen
Keyword(s):  
Drosophila Melanogaster ◽  
Temperature Response ◽  
Intrinsic Property ◽  
Developmental Rate ◽  
Time Lapse ◽  
Thermal Fluctuations ◽  
Early Embryo ◽  
Oxygen Levels ◽  
Time Lapse Imaging ◽  
Uniform Scaling

We previously demonstrated that, while changes in temperature produce dramatic shifts in the time elapsed duringDrosophila melanogasterembryogenesis, the relative timing of events within embryogenesis does not change. However, it was unclear if this uniform scaling is an intrinsic property of developing embryos, or if it is specific to thermal fluctuations. To investigate this, here we characterize the embryonic response to changes in oxygen concentration, which also impact developmental rate, using time-lapse imaging, and find it fundamentally different from the temperature response. Most notably, changes in oxygen levels drive developmental heterochrony, with the timing of several morphological processes showing distinct scaling behaviors. Gut formation is severely slowed by decreases in oxygen, while head involution and syncytial development are less impacted than the rest of development, and the order of several developmental landmarks is inverted at different oxygen levels. These data reveal that the uniform scaling seen with changes in temperature is not a trivial consequence of adjusting developmental rate. The developmental rate changes produced by changing oxygen concentrations dwarf those induced by temperature, and greatly impact survival. While extreme temperatures increase early embryo mortality, mild hypoxia increases arrest and death during mid-embryogenesis and mild hyperoxia increases survival over normoxia.

scholarly journals Temporal and spatial coordination of chromosome movement, spindle formation, and nuclear envelope breakdown during prometaphase in Drosophila melanogaster embryos.

1990 ◽  
Vol 111 (6) ◽  
pp. 2815-2828 ◽  
Author(s):  
Y Hiraoka ◽  
D A Agard ◽  
J W Sedat
Keyword(s):  
Drosophila Melanogaster ◽  
Nuclear Envelope ◽  
Temporal Dynamics ◽  
Three Dimensional ◽  
Metaphase Plate ◽  
Time Lapse ◽  
Three Dimensions ◽  
Nuclear Envelope Breakdown ◽  
High Resolution Analysis ◽  
Nuclear Structures

The spatial and temporal dynamics of diploid chromosome organization, microtubule arrangement, and the state of the nuclear envelope have been analyzed in syncytial blastoderm embryos of Drosophila melanogaster during the transition from prophase to metaphase, by three-dimensional optical sectioning microscopy. Time-lapse, three-dimensional data recorded in living embryos revealed that congression of chromosomes (the process whereby chromosomes move to form the metaphase plate) at prometaphase occurs as a wave, starting at the top of the nucleus near the embryo surface and proceeding through the nucleus to the bottom. The time-lapse analysis was augmented by a high-resolution analysis of fixed embryos where it was possible to unambiguously trace the three-dimensional paths of individual chromosomes. In prophase, the centromeres were found to be clustered at the top of the nucleus while the telomeres were situated at the bottom of the nucleus or towards the embryo interior. This polarized centromere-telomere orientation, perpendicular to the embryo surface, was preserved during the process of prometaphase chromosome congression. Correspondingly, breakdown of the nuclear envelope started at the top of the nucleus with the mitotic spindle being formed at the positions of the partial breakdown of the nuclear envelope. Our observation provide an example in which nuclear structures are spatially organized and their functions are locally and coordinately controlled in three dimensions.

scholarly journals In vitro endoderm emergence and self-organisation in the absence of extraembryonic tissues and embryonic architecture

2020 ◽  
Author(s):  
Stefano Vianello ◽  
Matthias P. Lutolf
Keyword(s):  
Cell Biology ◽  
Three Dimensional ◽  
Embryonic Stem ◽  
Cell Lineage ◽  
Early Embryo ◽  
Germ Layer ◽  
Epithelial Compartment ◽  
Endoderm Development ◽  
The Relationship

The endoderm is the cell lineage which gives rise in the embryo to the organs of the respiratory and gastrointestinal system. In the mouse this may be the germ layer with the strongest association with its extraembryonic counterpart. Uniquely indeed, endodermal tissue does not just derive from descendants of the embryo proper (the epiblast) but instead arises from their gradual incorporation into an extraembryonic substrate (the visceral endoderm). Given the configuration of the early embryo, such a paradigm requires epiblast endodermal progenitors to negotiate embryonic compartments with very diverse epithelial character, a developmental contingency reflected by the fact that key early endodermal markers such as Foxa2 and Sox17 have been consistently found to be embedded within gene programmes involved in epithelialisation.To explore the underlying cell biology of embryonic endoderm precursors, and to explore the relationship between endoderm development, epithelial identity, and extraembryonic mixing, we leveraged Gastruloids, in vitro models of early development. These self-organising three-dimensional aggregates of mouse embryonic stem cells do not possess an extraembryonic component, nor do they appear to display typical tissue architecture. Yet, they generate cells expressing endodermal markers. By tracking these cells throughout in vitro development, we highlight a persistent and uninterrupted pairing between epithelial and endodermal identity, with FoxA2+/Sox17+ endoderm progenitors never transitioning through mesenchymal intermediates and never leaving the epithelial compartment in which they arise. We also document the dramatic morphogenesis of these progenitors into a macroscopic epithelial primordium extending along the entire anterior-posterior axis of the Gastruloid, patterned into broad domains of gene expression. Corollarily we thus also highlight a strong epithelial component in Gastruloids, and thus the spontaneous emergence in vitro of stratified architectures and germ layer compartmentalisation.

Sea Urchins and Circuses: The Modernist Natural Histories of Jean Painlevé and Alexander Calder

2018 ◽  
Vol 13 (2) ◽  
pp. 187-211
Author(s):  
Patricia E. Chu
Keyword(s):  
New Media ◽  
Sea Urchins ◽  
Life Sciences ◽  
Three Dimensional ◽  
Machine Age ◽  
Avant Garde ◽  
History Of ◽  
And Performance ◽  
The One ◽  
Natural Historian

The Paris avant-garde milieu from which both Cirque Calder/Calder's Circus and Painlevé’s early films emerged was a cultural intersection of art and the twentieth-century life sciences. In turning to the style of current scientific journals, the Paris surrealists can be understood as engaging the (life) sciences not simply as a provider of normative categories of materiality to be dismissed, but as a companion in apprehending the “reality” of a world beneath the surface just as real as the one visible to the naked eye. I will focus in this essay on two modernist practices in new media in the context of the history of the life sciences: Jean Painlevé’s (1902–1989) science films and Alexander Calder's (1898–1976) work in three-dimensional moving art and performance—the Circus. In analyzing Painlevé’s work, I discuss it as exemplary of a moment when life sciences and avant-garde technical methods and philosophies created each other rather than being classified as separate categories of epistemological work. In moving from Painlevé’s films to Alexander Calder's Circus, Painlevé’s cinematography remains at the forefront; I use his film of one of Calder's performances of the Circus, a collaboration the men had taken two decades to complete. Painlevé’s depiction allows us to see the elements of Calder's work that mark it as akin to Painlevé’s own interest in a modern experimental organicism as central to the so-called machine-age. Calder's work can be understood as similarly developing an avant-garde practice along the line between the bestiary of the natural historian and the bestiary of the modern life scientist.

Computed Tomography and Magnetic Resonance Imaging-aided Diagnosis of Primary Essential Cutis Verticis Gyrata: A Case Report with 5-year Follow-up and Review of the Literature

2019 ◽  
Vol 15 (9) ◽  
pp. 906-910
Author(s):  
Hongzhang Zhu ◽  
Shi-Ting Feng ◽  
Xingqi Zhang ◽  
Zunfu Ke ◽  
Ruixi Zeng ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Three Dimensional ◽  
Stable Condition ◽  
Resonance Imaging ◽  
Mri Findings ◽  
Cutis Verticis Gyrata ◽  
Essential Form ◽  
History Of ◽  
Magnetic Resonance Imaging Mri

Background: Cutis Verticis Gyrata (CVG) is a rare skin disease caused by overgrowth of the scalp, presenting as cerebriform folds and wrinkles. CVG can be classified into two forms: primary (essential and non-essential) and secondary. The primary non-essential form is often associated with neurological and ophthalmological abnormalities, while the primary essential form occurs without associated comorbidities. Discussion: We report on a rare case of primary essential CVG with a 4-year history of normal-colored scalp skin mass in the parietal-occipital region without symptom in a 34-year-old male patient, retrospectively summarizing his pathological and Computer Tomography (CT) and magnetic resonance imaging (MRI) findings. The major clinical observations on the CT and MR sectional images include a thickened dermis and excessive growth of the scalp, forming the characteristic scalp folds. With the help of CT and MRI Three-dimensional (3D) reconstruction techniques, the characteristic skin changes could be displayed intuitively, providing more evidence for a diagnosis of CVG. At the 5-year followup, there were no obvious changes in the lesion. Conclusion: Based on our observations, we propose that not all patients with primary essential CVG need surgical intervention, and continuous clinical observation should be an appropriate therapy for those in stable condition.

scholarly journals Sirenomelia: two case reports

2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Asiyeh Shojaee ◽  
Firooze Ronnasian ◽  
Mahdiyeh Behnam ◽  
Mansoor Salehi
Keyword(s):  
Case Reports ◽  
Three Dimensional ◽  
First Trimester ◽  
Mendelian Inheritance ◽  
Lower Limbs ◽  
Congenital Deformity ◽  
White Family ◽  
Her Family ◽  
Caudal Regression ◽  
History Of

AbstractBackgroundSirenomelia, also called mermaid syndrome, is a rare lethal multi-system congenital deformity with an incidence of one in 60,000–70,000 pregnancies. Sirenomelia is mainly characterized by the fusion of lower limbs and is widely associated with severe urogenital and gastrointestinal malformations. The presence of a single umbilical artery derived from the vitelline artery is the main anatomical feature distinguishing sirenomelia from caudal regression syndrome. First-trimester diagnosis of this disorder and induced abortion may be the safest medical option. In this report, two cases of sirenomelia that occurred in an white family will be discussed.Case presentationWe report two white cases of sirenomelia occurring in a 31-year-old multigravid pregnant woman. In the first pregnancy (18 weeks of gestation) abortion was performed, but in the third pregnancy (32 weeks) the stillborn baby was delivered by spontaneous vaginal birth. In the second and fourth pregnancies, however, she gave birth to normal babies. Three-dimensional ultrasound imaging showed fusion of the lower limbs. Neither she nor any member of her family had a history of diabetes. In terms of other risk factors, she had no history of exposure to teratogenic agents during her pregnancy. Also, her marriage was non-consanguineous.ConclusionThis report suggests the existence of a genetic background in this mother with a Mendelian inheritance pattern of 50% second-generation incidence in her offspring.

scholarly journals Multi-Locus Selection and the Structure of Variation at the white Gene of Drosophila melanogaster

Genetics ◽  
1996 ◽  
Vol 144 (2) ◽  
pp. 635-645 ◽  
Author(s):  
David A Kirby ◽  
Wolfgang Stephan
Keyword(s):  
Drosophila Melanogaster ◽  
White Gene ◽  
Transcriptional Unit ◽  
North American Population ◽  
Evolutionary Mechanisms ◽  
Locus Selection ◽  
Neutral Equilibrium ◽  
History Of ◽  
High Degree ◽  
Very High

Abstract We surveyed sequence variation and divergence for the entire 5972-bp transcriptional unit of the white gene in 15 lines of Drosophila melanogaster and one line of D. simulans. We found a very high degree of haplotypic structuring for the polymorphisms in the 3′ half of the gene, as opposed to the polymorphisms in the 5′ half. To determine the evolutionary mechanisms responsible for this pattern, we sequenced a 1612-bp segment of the white gene from an additional 33 lines of D. melanogaster from a European and a North American population. This 1612-bp segment encompasses an 834bp region of the white gene in which the polymorphisms form high frequency haplotypes that cannot be explained by a neutral equilibrium model of molecular evolution. The small number of recombinants in the 834bp region suggests epistatic selection as the cause of the haplotypic structuring, while an investigation of nucleotide diversity supports a directional selection hypothesis. A multi-locus selection model that combines features from both-hypotheses and takes the recent history of D. melanogaster into account may be the best explanation for these data.

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