Isolating Postimplantation Embryos: Early Somite-Stage

2006 ◽  
Vol 2006 (1) ◽  
pp. pdb.prot4366
Author(s):  
Andras Nagy ◽  
Marina Gertsenstein ◽  
Kristina Vintersten ◽  
Richard Behringer
Keyword(s):  
Somite Stage

Optical approaches to ontogeny of electrical activity and related functional organization during early heart development

1991 ◽  
Vol 71 (1) ◽  
pp. 53-91 ◽  
Author(s):  
K. Kamino
Keyword(s):  
Electrical Activity ◽  
Heart Development ◽  
Functional Organization ◽  
Embryonic Heart ◽  
Optical Recording ◽  
Additional Advantage ◽  
Physiological Functions ◽  
Spontaneous Electrical Activity ◽  
Somite Stage ◽  
Voltage Sensitive Dyes

Direct intracellular measurement of electrical events in the early embryonic heart is impossible because the cells are too small and frail to be impaled with microelectrodes; it is also not possible to apply conventional electrophysiological techniques to the early embryonic heart. For these reasons, complete understanding of the ontogeny of electrical activity and related physiological functions of the heart during early development has been hampered. Optical signals from voltage-sensitive dyes have provided a new powerful tool for monitoring changes in transmembrane voltage in a wide variety of living preparations. With this technique it is possible to make optical recordings from the cells that are inaccessible to microelectrodes. An additional advantage of the optical method for recording membrane potential activity is that electrical activity can be monitored simultaneously from many sites in a preparation. Thus, applying a multiple-site optical recording method with a 100- or 144-element photodiode array and voltage-sensitive dyes, we have been able to monitor, for the first time, spontaneous electrical activity in prefused cardiac primordia in the early chick embryos at the six- and the early seven-somite stages of development. We were able to determine that the time of initiation of the contraction is the middle period of the nine-somite stage. In the rat embryonic heart, the onset of spontaneous electrical activity and contraction occurs at the three-somite stage. In this review, a new view of the ontogenetic sequence of spontaneous electrical activity and related physiological functions such as ionic properties, pacemaker function, conduction, and characteristics of excitation-contraction coupling in the early embryonic heart are discussed.

Determination of sclerotome to the cartilage fate

Development ◽  
1998 ◽  
Vol 125 (11) ◽  
pp. 2113-2124 ◽  
Author(s):  
J.L. Dockter ◽  
C.P. Ordahl
Keyword(s):  
Vertebral Body ◽  
Host Age ◽  
Somite Stage ◽  
Dorsal Position ◽  
Lineage Diversification

When the somite first forms the cells appear to be equivalent in potential. In order to understand the lineage diversification of the somite, the determination of sclerotome cells to the cartilage fate was tested using an in vivo challenge assay in which quail sclerotome fragments were grafted into a dorsal position in a chick host. Grafts containing undetermined cells were expected to differentiate into other tissues while grafts containing determined chondrocyte precursors were expected to consistently give rise to cartilage. We found that grafted sclerotome fragments from somite stages V-XX were capable of giving rise to integrated muscle and dermis and that it was not until fragments from stage XII somites were grafted that cartilage was consistently produced in the assay. Sclerotomal tissue from embryonic day 4–6 embryos remained as morphologically unintegrated mesenchyme when grafted into an embryonic day 2 host, but formed only cartilage when placed into an identically aged host. Vertebral body cartilage from embryonic day 7 and embryonic day 8 embryos formed exclusively ectopic cartilage in an embryonic day 2 host. We conclude that cells determined to the cartilage fate do not appear until somite stage XII, but that not all sclerotome cells are determined at this time. The effect of host age on the differentiation and morphogenetic behavior of sclerotome fragment grafts in this assay indicate the existence of developmental eras within the embryo.

scholarly journals Vasculogenesis in the early quail blastodisc as studied with a monoclonal antibody recognizing endothelial cells

Development ◽  
1987 ◽  
Vol 100 (2) ◽  
pp. 339-349 ◽  
Author(s):  
L. Pardanaud ◽  
C. Altmann ◽  
P. Kitos ◽  
F. Dieterlen-Lievre ◽  
C.A. Buck
Keyword(s):  
Monoclonal Antibody ◽  
Endothelial Cells ◽  
Single Cells ◽  
Primitive Streak ◽  
Vascular Network ◽  
Vascular Tree ◽  
Somite Stage ◽  
Area Vasculosa ◽  
Haemopoietic Cells ◽  
Area Pellucida

QH1, a monoclonal antibody that recognizes quail endothelial and haemopoietic cells, was applied to quail blastodiscs in toto, in order to analyse by immunofluorescence the emergence of the vascular tree. The first endothelial cells were detected in the area opaca at the headfold stage and in the area pellucida at the 1-somite stage. Single cells then interconnected progressively, especially in the anterior intestinal portal and along the somites building up the linings of the heart and dorsal aortas. This study demonstrates that endothelial cells differentiate as single entities 4 h earlier in development than hitherto detected and that the vascular network forms secondarily. The horseshoe shape of the extraembryonic area vasculosa is also a secondary acquisition. A nonvascularized area persists until later (at least the 14-somite stage) in the region of the regressing primitive streak.

Generation of Fertile and Diploid Fish, Medaka (Oryzias latipes), from Nuclear Transplantation of Blastula and Four-Somite-Stage Embryonic Cells into Nonenucleated Unfertilized Eggs

2005 ◽  
Vol 7 (4) ◽  
pp. 255-264 ◽  
Author(s):  
Ekaterina Bubenshchikova ◽  
Bensheng Ju ◽  
Inna Pristyazhnyuk ◽  
Katsutoshi Niwa ◽  
Elena Kaftanovskaya ◽  
...  
Keyword(s):  
Oryzias Latipes ◽  
Nuclear Transplantation ◽  
Embryonic Cells ◽  
Somite Stage

A spinal cord fate map in the avian embryo: while regressing, Hensen's node lays down the notochord and floor plate thus joining the spinal cord lateral walls

Development ◽  
1996 ◽  
Vol 122 (9) ◽  
pp. 2599-2610 ◽  
Author(s):  
M. Catala ◽  
M.A. Teillet ◽  
E.M. De Robertis ◽  
M.L. Le Douarin
Keyword(s):  
Spinal Cord ◽  
Primitive Streak ◽  
Floor Plate ◽  
Dorsal Side ◽  
Avian Embryo ◽  
Tail Bud ◽  
Fate Map ◽  
In Ovo ◽  
Somite Stage ◽  
Lateral Walls

The spinal cord of thoracic, lumbar and caudal levels is derived from a region designated as the sinus rhomboidalis in the 6-somite-stage embryo. Using quail/chick grafts performed in ovo, we show the following. (1) The floor plate and notochord derive from a common population of cells, located in Hensen's node, which is equivalent to the chordoneural hinge (CNH) as it was defined at the tail bud stage. (2) The lateral walls and the roof of the neural tube originate caudally and laterally to Hensen's node, during the regression of which the basal plate anlage is bisected by floor plate tissue. (3) Primary and secondary neurulations involve similar morphogenetic movements but, in contrast to primary neurulation, extensive bilateral cell mixing is observed on the dorsal side of the region of secondary neurulation. (4) The posterior midline of the sinus rhomboidalis gives rise to somitic mesoderm and not to spinal cord. Moreover, mesodermal progenitors are spatially arranged along the rest of the primitive streak, more caudal cells giving rise to more lateral embryonic structures. Together with the results reported in our study of tail bud development (Catala, M., Teillet, M.-A. and Le Douarin, N.M. (1995). Mech. Dev. 51, 51–65), these results show that the mechanisms that preside at axial elongation from the 6-somite stage onwards are fundamentally similar during the complete process of neurulation.

In vitro study of chorionic and ectoplacental trophoblast differentiation in the mouse

Development ◽  
1975 ◽  
Vol 34 (3) ◽  
pp. 633-644
Author(s):  
Danièle Hernandez-Verdun ◽  
Chantal Legrand
Keyword(s):  
Electron Microscopy ◽  
Morphological Study ◽  
Light And Electron Microscopy ◽  
In Vitro Study ◽  
Capillary Network ◽  
Vitro Study ◽  
Trophoblast Cells ◽  
Trophoblast Differentiation ◽  
Somite Stage

Mouse chorioallantoic pre-placental structures alone or in association with the embryo were explanted during the 9th day of gestation (7-somite stage) and cultured in a static medium for 24 to 48 h. From the subsequent morphological study of trophoblast differentiation, using both light and electron microscopy, we draw the following conclusions. 1. The allantoic mesoderm cells migrate inside the trophoblastic population but they do not differentiate a capillary network and trophoblast cells phagocytose the existing foetal erythrocytes. 2. In the absence of allantoic mesoderm, chorionic trophoblast cells remain undifferentiated. 3. The development of the chorionic trophoblast is modified in that chorionic trophoblast cells fail to establish close junctions with ectoplacental trophoblast, and some chorionic cells initiate the formation of multinucleated syncytia. The genesis of these syncytia is discussed.

scholarly journals Immunocytochemical studies of cardiac myofibrillogenesis in early chick embryos. III. Generation of fasciae adherentes and costameres.

1989 ◽  
Vol 108 (1) ◽  
pp. 43-53 ◽  
Author(s):  
K T Tokuyasu
Keyword(s):  
Cell Membranes ◽  
Spatial Information ◽  
De Novo ◽  
Three Dimensional ◽  
Myocardial Cell ◽  
Double Labeling ◽  
Rhodamine Phalloidin ◽  
Somite Stage ◽  
Myocardial Wall ◽  
Cell Layers

To study whether the first myofibrils are separate from or firmly bound to the myocytic cell membranes, whole mount preparations of 6-12-somite-stage chick embryonic hearts were examined by fluorescence microscopy after double labeling with antibodies to vinculin (fluorescein-conjugated) and rhodamine-phalloidin, or with antibodies to titin (rhodamine-conjugated) and nitrobenz-oxadiazole-phallacidin. When a small number of myofibrils appeared for the first time at the nine somite stage, most of them were already bound to the cell membranes through zonulae adherentes, fasciae adherentes, or costameres. In the outer of the two myocardial cell layers, in which the myocytes were closely in contact with each other along polygonal boundaries, fasciae adherentes and costameres developed at the boundaries, apparently by conversion of preexisting zonulae adherentes. On the other hand, in the inner cell layer, in which myocytes were more loosely associated with each other, both costameres and fasciae adherentes appeared to develop de novo, the former in association with the inner surface of the myocardial wall and the latter at the intercellular boundaries. The myofibrillar tracks in the inner layer followed long and smooth courses and were as a whole aligned in the circumferential direction of the tubular heart wall from the earliest stage of myofibril formation. Those in the outer layer were arranged in a pattern of two- or three-dimensional networks in the 9-10 somite stage, although many myofibrils were also circumferentially directed. The fact that the majority of the first myofibrils were already bound to the cell membranes in a directed manner suggests that myocytes at the earliest stage of myofibril formation are endowed with spatial information that directs the organization of nascent myofibrils. It is proposed that the myocyte cell membranes perform an essential role in cardiac myofibrillogenesis.

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