Ontogeny and behaviour of early macrophages in the zebrafish embryo

Development ◽  
1999 ◽  
Vol 126 (17) ◽  
pp. 3735-3745 ◽  
Author(s):  
P. Herbomel ◽  
B. Thisse ◽  
C. Thisse
Keyword(s):  
Zebrafish Embryo ◽  
Marker Genes ◽  
Erythroid Cells ◽  
Differential Interference Contrast Microscopy ◽  
Macrophage Population ◽  
Blood Island ◽  
Interference Contrast Microscopy ◽  
Lateral Mesoderm ◽  
Hemopoietic Organs

In the zebrafish embryo, the only known site of hemopoieisis is an intra-embryonic blood island at the junction between trunk and tail that gives rise to erythroid cells. Using video-enhanced differential interference contrast microscopy, as well as in-situ hybridization for the expression of two new hemopoietic marker genes, draculin and leucocyte-specific plastin, we show that macrophages appear in the embryo at least as early as erythroid cells, but originate from ventro-lateral mesoderm situated at the other end of the embryo, just anterior to the cardiac field. These macrophage precursors migrate to the yolksac, and differentiate. From the yolksac, many invade the mesenchyme of the head, while others join the blood circulation. Apart from phagocytosing apoptotic corpses, these macrophages were observed to engulf and destroy large amounts of bacteria injected intravenously; the macrophages also sensed the presence of bacteria injected into body cavities that are isolated from the blood, migrated into these cavities and eradicated the microorganisms. Moreover, we observed that although only a fraction of the macrophage population goes to the site of infection, the entire population acquires an activated behaviour, similar to that of activated macrophages in mammals. Our results support the notion that in vertebrate embryos, macrophages endowed with proliferative capacity arise early from the hemopoietic lineage through a non-classical, rapid differentiation pathway, which bypasses the monocytic series that is well-documented in adult hemopoietic organs.

scholarly journals In situ observation of biotite (001) surface dissolution at pH 1 and 9.5 by advanced optical microscopy

2015 ◽  
Vol 6 ◽  
pp. 665-673 ◽  
Author(s):  
Chiara Cappelli ◽  
Daniel Lamarca-Irisarri ◽  
Jordi Camas ◽  
F Javier Huertas ◽  
Alexander E S Van Driessche
Keyword(s):  
Secondary Phase ◽  
In Situ Observation ◽  
Differential Interference Contrast Microscopy ◽  
Confocal Raman Spectroscopy ◽  
Solution Ph ◽  
Contrast Microscopy ◽  
Interference Contrast Microscopy ◽  
Step Edges

Laser confocal differential interference contrast microscopy (LCM-DIM) allows for the study of the reactivity of surface minerals with slow dissolution rates (e.g., phyllosilicates). With this technique, it is possible to carry out in situ inspection of the reacting surface in a broad range of pH, ionic strength and temperature providing useful information to help unravel the dissolution mechanisms of phyllosilicates. In this work, LCM-DIM was used to study the mechanisms controlling the biotite (001) surface dissolution at pH 1 (11 and 25 °C) and pH 9.5 (50 °C). Step edges are the preferential sites of dissolution and lead to step retreat, regardless of the solution pH. At pH 1, layer swelling and peeling takes place, whereas at pH 9.5 fibrous structures (streaks) form at the step edges. Confocal Raman spectroscopy characterization of the reacted surface could not confirm if the formation of a secondary phase was responsible for the presence of these structures.

scholarly journals Significance of Enhanced Morphological Detection of Cryptosporidium sp. Oocysts in Water Concentrates Determined by Using 4′,6′-Diamidino-2-Phenylindole and Immunofluorescence Microscopy

2002 ◽  
Vol 68 (10) ◽  
pp. 5198-5201 ◽  
Author(s):  
H.V. Smith ◽  
B. M. Campbell ◽  
C. A. Paton ◽  
R. A. B. Nichols
Keyword(s):  
Fluorescein Isothiocyanate ◽  
Alternative Methods ◽  
Water Type ◽  
Raw Water ◽  
Differential Interference Contrast Microscopy ◽  
Oocyst Wall ◽  
Nomarski Differential Interference Contrast ◽  
Contrast Microscopy ◽  
Interference Contrast Microscopy

ABSTRACT Of 2,361 water concentrates analyzed for the presence of Cryptosporidium spp. oocysts between January 1992 and May 1998, 269 (11.4%) were positive, of which 235 (87.4%) were raw and 34 were final water concentrates. Of 740 oocysts enumerated in positive samples, 656 oocysts (88.7%) were detected in raw and 84 oocysts (11.3%) were detected in final water concentrates by using a commercially available fluorescein isothiocyanate-labeled anti-Cryptosporidium sp. monoclonal antibody and the nuclear fluorogen 4′,6′-diamidino-2-phenylindole (DAPI). Of raw water positive samples, 66.8% had oocysts that contained nuclei, while 58.8% of final water samples had oocysts that contained nuclei. The most frequently identified oocysts had either no DAPI-positive nuclei and no internal morphology according to Nomarski differential interference-contrast microscopy (DIC) or four DAPI-positive nuclei together with internal contents according to DIC (39.5 and 32.8% of raw and 42.9 and 30.9% of final water positives, respectively). By use of the presence of DAPI-stained nuclei to support oocyst identification based upon oocyst wall fluorescence, 56.5% of oocysts were identified when at least one nucleus was present, while increasing the number of nuclei necessary for identification to four reduced the percentage identifiable to 32.8% in raw water concentrates. In final water concentrates, 51% of oocysts were identified using oocyst wall fluorescence and the presence of at least one nucleus, while increasing the number of nuclei necessary for identification to four reduced the percentage identifiable to 30.9%. By consolidating our identification criteria from the presence of at least one nucleus to the presence of four nuclei, we excluded approximately 20% of oocysts in either water type. Approximately 40% of oocysts detected in these United Kingdom samples were empty and could not be detected by alternative methods, including the PCR and fluorescence in situ hybridization.

scholarly journals Minus-end capture of preformed kinetochore fibers contributes to spindle morphogenesis

2003 ◽  
Vol 160 (5) ◽  
pp. 671-683 ◽  
Author(s):  
Alexey Khodjakov ◽  
Lily Copenagle ◽  
Michael B. Gordon ◽  
Duane A. Compton ◽  
Tarun M. Kapoor
Keyword(s):  
Three Dimensional ◽  
Differential Interference Contrast ◽  
Differential Interference Contrast Microscopy ◽  
Spindle Formation ◽  
Capture Mechanism ◽  
Contrast Microscopy ◽  
Interference Contrast Microscopy ◽  
Kinesin Eg5 ◽  
Mitotic Kinesin Eg5 ◽  
Dependent Mechanism

Near-simultaneous three-dimensional fluorescence/differential interference contrast microscopy was used to follow the behavior of microtubules and chromosomes in living α-tubulin/GFP-expressing cells after inhibition of the mitotic kinesin Eg5 with monastrol. Kinetochore fibers (K-fibers) were frequently observed forming in association with chromosomes both during monastrol treatment and after monastrol removal. Surprisingly, these K-fibers were oriented away from, and not directly connected to, centrosomes and incorporated into the spindle by the sliding of their distal ends toward centrosomes via a NuMA-dependent mechanism. Similar preformed K-fibers were also observed during spindle formation in untreated cells. In addition, upon monastrol removal, centrosomes established a transient chromosome-free bipolar array whose orientation specified the axis along which chromosomes segregated. We propose that the capture and incorporation of preformed K-fibers complements the microtubule plus-end capture mechanism and contributes to spindle formation in vertebrates.

Pattern of the insulin-like growth factor II gene expression during early mouse embryogenesis

Development ◽  
1990 ◽  
Vol 110 (1) ◽  
pp. 151-159 ◽  
Author(s):  
J.E. Lee ◽  
J. Pintar ◽  
A. Efstratiadis
Keyword(s):  
Growth Factor ◽  
Immunohistochemical Analysis ◽  
Primitive Streak ◽  
Insulin Like Growth Factor ◽  
Surface Ectoderm ◽  
Factor Ii ◽  
Extraembryonic Mesoderm ◽  
Early Mouse ◽  
Lateral Mesoderm

The mouse insulin-like growth factor II (IGF-II) gene encodes a polypeptide that plays a role in embryonic growth. We have examined the temporal and spatial pattern of expression of this gene in sections of the mouse conceptus between embryonic days 4.0 and 8.5 by in situ hybridization. Abundant IGF-II transcripts were detected in all the trophectodermal derivatives, after implantation. Labeling was then observed in primitive endoderm, but was transient and disappeared after formation of the yolk sac. Expression was next detected in extraembryonic mesoderm at the early primitive streak stage. Labeling in the embryo proper appeared first at the late primitive streak/neural plate stage in lateral mesoderm and in anterior-proximal cells located between the visceral endoderm and the most cranial region of the embryonic ectoderm. The position of the latter cells suggests that their descendants are likely to participate in the formation of the heart and the epithelium of the ventral and lateral walls of the foregut, where intense labeling was observed at the neural fold stage. Hybridization was also detected in cranial mesenchyme, including neural crest cells. The intensity of hybridization signal increased progressively in paraxial (presomitic and somitic) mesoderm, while declining in the ectoplacental cone. The neuroectoderm and surface ectoderm did not exhibit hybridization at any stage. Immunohistochemical analysis indicated co-localization of IGF-II transcripts, translated pre-pro-IGF-II, and the cognate IGF-II/mannose-6-phosphate receptor. These correlations are consistent with the hypothesis that IGF-II has an autocrine function.

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