scholarly journals Pseudo-dynamic analysis of heart tube formation in the mouse reveals strong regional variability and early left-right asymmetry

2021 ◽  
Author(s):  
Isaac Esteban ◽  
Patrick Schmidt ◽  
Susana Temino ◽  
Leif Kobbelt ◽  
Miguel Torres
Keyword(s):  
Heart Development ◽  
Computer Modelling ◽  
Morphological Variability ◽  
Tube Formation ◽  
Morphological Description ◽  
Heart Tube ◽  
Regional Variability ◽  
Mammalian Embryo ◽  
Morphological Variations ◽  
Left Right Asymmetry

Understanding organ morphogenesis requires a precise geometrical description of the tissues involved in the process. In highly regulative embryos, like those of mammals, morphological variability hinders the quantitative analysis of morphogenesis. In particular, the study of early heart development in mammals remains a challenging problem, due to imaging limitations and innate complexity. Around embryonic day 7.5 (E7.5), the cardiac crescent folds in an intricate and coordinated manner to produce a pumping linear heart tube at E8.25, followed by heart looping at E8.5. In this work we provide a complete morphological description of this process based on detailed imaging of a temporally dense collection of embryonic heart morphologies. We apply new approaches for morphometric staging and quantification of local morphological variations between specimens at the same stage. We identify hot spots of regionalized variability and identify left-right asymmetry in the inflow region starting at the late cardiac crescent stage, which represents the earliest signs of organ left-right asymmetry in the mammalian embryo. Finally, we generate a 3D+t digital model that provides a framework suitable for co-representation of data from different sources and for the computer modelling of the process.

scholarly journals Hey2 restricts cardiac progenitor addition to the developing heart

2017 ◽  
Author(s):  
Natalie Gibb ◽  
Savo Lazic ◽  
Ashish R. Deshwar ◽  
Xuefei Yuan ◽  
Michael D. Wilson ◽  
...  
Keyword(s):  
Heart Development ◽  
Heart Defects ◽  
Myocardial Cell ◽  
Cell Number ◽  
Tube Formation ◽  
Heart Tube ◽  
Cardiac Progenitors ◽  
Developing Heart ◽  
Heart Field ◽  
A Cell

ABSTRACTA key event in vertebrate heart development is the timely addition of second heart field (SHF) progenitor cells to the poles of the heart tube. This accretion process must occur to the proper extent to prevent a spectrum of congenital heart defects (CHDs). However, the factors that regulate this critical process are poorly understood. Here we demonstrate that Hey2, a bHLH transcriptional repressor, restricts SHF progenitor accretion to the zebrafish heart. hey2 expression demarcated a distinct domain within the cardiac progenitor population. In the absence of Hey2 function an increase in myocardial cell number and SHF progenitors was observed. We found that Hey2 limited proliferation of SHF-derived cardiomyocytes in a cell-autonomous manner, prior to heart tube formation, and further restricted the developmental window over which SHF progenitors were deployed to the heart. Taken together, our data suggests a role for Hey2 in controlling the proliferative capacity and cardiac contribution of late-differentiating cardiac progenitors.

scholarly journals The Expanding Role for Retinoid Signaling in Heart Development

2008 ◽  
Vol 8 ◽  
pp. 194-211 ◽  
Author(s):  
Loretta L. Hoover ◽  
Elizabeth G. Burton ◽  
Bonnie A. Brooks ◽  
Steven W. Kubalak
Keyword(s):  
Vitamin A ◽  
Heart Development ◽  
Cardiac Development ◽  
Tube Formation ◽  
Conditional Knockout ◽  
Heart Tube ◽  
Developmental Defects ◽  
Retinoid Signaling ◽  
Developing Heart ◽  
Cardiac Lineage

The importance of retinoid signaling during cardiac development has long been appreciated, but recently has become a rapidly expanding field of research. Experiments performed over 50 years ago showed that too much or too little maternal intake of vitamin A proved detrimental for embryos, resulting in a cadre of predictable cardiac developmental defects. Germline and conditional knockout mice have revealed which molecular players in the vitamin A signaling cascade are potentially responsible for regulating specific developmental events, and many of these molecules have been temporally and spatially characterized. It is evident that intact and controlled retinoid signaling is necessary for each stage of cardiac development to proceed normally, including cardiac lineage determination, heart tube formation, looping, epicardium formation, ventricular maturation, chamber and outflow tract septation, and coronary arteriogenesis. This review summarizes many of the significant milestones in this field and particular attention is given to recently uncovered cross-talk between retinoid signaling and other developmentally significant pathways. It is our hope that this review of the role of retinoid signaling during formation, remodeling, and maturation of the developing heart will serve as a tool for future discoveries.

Dosage requirement of Pitx2 for development of multiple organs

Development ◽  
1999 ◽  
Vol 126 (20) ◽  
pp. 4643-4651 ◽  
Author(s):  
P.J. Gage ◽  
H. Suh ◽  
S.A. Camper
Keyword(s):  
Heart Development ◽  
Threshold Level ◽  
The Body ◽  
Null Alleles ◽  
Allelic Series ◽  
Heart Tube ◽  
Rieger Syndrome ◽  
Multiple Organs ◽  
Abdominal Organs ◽  
Left Right Asymmetry

Pitx2 is a homeodomain transcription factor that is mutated in Rieger syndrome, a haploinsufficiency disorder affecting eyes and teeth. Pitx2 also has a postulated role in left-right axis determination. We assessed the requirements for Pitx2 directly by generating hypomorphic and null alleles. Heterozygotes for either allele have eye abnormalities consistent with Rieger syndrome. The ventral body wall fails to close in embryos homozygous for the null allele, leaving the heart and abdominal organs externalized and the body axis contorted. In homozygotes for either allele, the heart tube undergoes normal, rightward looping and the stomach is positioned normally. In contrast, homozygotes for both alleles exhibit right isomerization of the lungs. Thus, Pitx2 is required for left-right asymmetry of the lungs but not other organs. Homozygotes for either allele exhibit septal and valve defects, and null homozygotes have a single atrium proving that a threshold level of Pitx2 is required for normal heart development. Null homozygotes exhibit arrest of pituitary gland development at the committed Rathke pouch stage and eye defects including optic nerve coloboma and absence of ocular muscles. This allelic series establishes that Pitx2 is required for the development of mulitple organs in a dosage-sensitive manner.

scholarly journals Endoderm Nitric Oxide Signals to Regulate Nascent Development of Cardiac Progenitors in Chicken Embryos

2020 ◽  
Author(s):  
Devan H. Shah ◽  
Sujoy K. Biswas ◽  
Adrian M. Martin ◽  
Simone Bianco ◽  
Wilfred F. Denetclaw
Keyword(s):  
Nitric Oxide ◽  
Heart Development ◽  
Tube Formation ◽  
Heart Tube ◽  
Signal Molecule ◽  
Cardiac Progenitors ◽  
Field Development ◽  
Physiological Signal ◽  
No Signaling ◽  
Differentiation And Proliferation

AbstractHeart development in the chicken embryo is regulated by a concert of cardiogenic morphogens and signaling molecules, but the physiological signal molecule nitric oxide(NO) has not been studied in the context of heart formation. A dynamic investigation of endoderm NO formation demonstrates for the first time a correlation with the established development events of the cardiac heart fields and heart tube. Manipulation of endoderm NO signaling demonstrate a role of NO signaling in the differentiation and proliferation of cardiac progenitors for heart tube formation and cardiac heart field development. To investigate NO in the proliferation of myocardial cells in the heart tube embryos, a computer vision based artificial intelligence approach is followed to automate the long and tedious job of counting cells in a large image dataset. We document NO as an important signaling molecule in the regulation of nascent embryonic cardiogenesis whose effects on other early cardiogenic morphogens is unknown.

scholarly journals Asymmetric Involution of the Myocardial Field Drives Heart Tube Formation in Zebrafish

2008 ◽  
Vol 102 (2) ◽  
Author(s):  
Stefan Rohr ◽  
Cécile Otten ◽  
Salim Abdelilah-Seyfried
Keyword(s):  
Tube Formation ◽  
Heart Tube ◽  
Heart Tube Formation

scholarly journals A polarized nucleus-cytoskeleton-ECM connection in migrating cardioblasts controls heart tube formation

Development ◽  
2021 ◽  
Author(s):  
Cristiana Dondi ◽  
Benjamin Bertin ◽  
Jean-Philippe Daponte ◽  
Inga Wojtowicz ◽  
Krzysztof Jagla ◽  
...  
Keyword(s):  
Expression Patterns ◽  
Tube Formation ◽  
Cardiac Cells ◽  
Collective Migration ◽  
Heart Tube ◽  
Adhesion Sites ◽  
Correct Alignment ◽  
Temporal And Spatial ◽  
Heart Tube Formation ◽  
Made In

The formation of the cardiac tube is a remarkable example of complex morphogenetic processes conserved from invertebrates to humans. It involves coordinated collective migration of contralateral rows of cardiac cells. The molecular processes underlying the specification of cardioblasts (CBs) prior to migration are well established and significant advances have been made in understanding the process of lumen formation. However, the mechanisms of collective cardiac cells migration remain elusive. Here we identified CAP and MSP300 as novel actors involved during CBs migration. They both exhibit highly similar temporal and spatial expression patterns in migrating cardiac cells and are necessary for the correct number and alignment of CBs, a prerequisite for the coordination of their collective migration. Our data suggest that CAP and MSP300 are part of a protein complex linking focal adhesion sites to nuclei via the actin cytoskeleton that maintains post-mitotic state and correct alignment of CBs.

scholarly journals Where should we draw the lines between dinocyst “species”? Morphological continua in Black Sea dinocysts

2019 ◽  
Vol 38 (1) ◽  
pp. 55-65 ◽  
Author(s):  
Thomas M. Hoyle ◽  
Manuel Sala-Pérez ◽  
Francesca Sangiorgi
Keyword(s):  
Black Sea ◽  
Genetic Difference ◽  
Morphological Variability ◽  
Intraspecific Variability ◽  
Nutrient Status ◽  
The Black Sea ◽  
Genetic Sequencing ◽  
Morphological Variations ◽  
Intermediate Phenotypes ◽  
Primary Driver

Abstract. The morphology of dinoflagellate cysts (dinocysts) is related not only to the genetics of the motile dinoflagellate from which it derives, but is also dependent on a range of environmental factors including salinity, temperature and nutrient status. Although this knowledge improves our understanding of the drivers behind dinocyst morphological variations, it makes the taxonomy governing their description somewhat complex. In basins such as the Black Sea, where environmental change can be extreme and occurs on relatively short (millennial) timescales, taxonomy becomes particularly challenging. Morphological continua can be observed between described forms, displaying a large range of intermediate phenotypes that do not necessarily correspond to any genetic difference. As these morphological nuances may preserve information about palaeoenvironments, it is important to find a systematic method of characterising morphotypes. Here, we show a dinocyst matrix within which dinocysts are described according to their similarity to (or difference from) described forms based on key descriptive parameters. In the example set out here, cyst shape and degree of process and/or ectophragm development are taken as two key parameters in Pyxidinopsis psilata and Spiniferites cruciformis, and can allow the description of intermediate forms even though the definitions do not overlap. We review some frequently occurring morphotypes and propose that using matrices to show the gradual variation between endmember forms is the most pragmatic approach until cyst–theca studies and genetic sequencing can be used to demonstrate relationships between genotypes and morphotypes. As prior studies propose salinity to be a primary driver of intraspecific variability, the endmembers presented may represent salinity extremes within an overall brackish environment. Although we cannot assign each morphotype to a value or a range of an environmental parameter (e.g. salinity) as the different morphotypes can occur in the same sample, using this matrix allows preservation of information about morphological variability without creating taxonomic categories that are likely to require alteration if genetic evidence becomes available.

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