Ultrastructural studies on the cerebellar histogenesis. I. Differentiation of granule cells and development of Glomeeruli in the chick embryo

1967 ◽  
Vol 77 (1) ◽  
pp. 115-143 ◽  
Author(s):  
Enrico Mugnaini ◽  
Paul F. Forstr�nen
Keyword(s):  
Chick Embryo ◽  
Granule Cells ◽  
Ultrastructural Studies ◽  
Cerebellar Histogenesis

Ultrastructural studies of Chlamydia psittaci 6BC variant strains. I. Ultrastructure of the surface layers of egg-passaged 6BC strain

1973 ◽  
Vol 19 (8) ◽  
pp. 887-894
Author(s):  
Linda Poffenroth ◽  
J. W. Costerton ◽  
Nonna Kordová ◽  
John C. Wilt
Keyword(s):  
Chick Embryo ◽  
Microscopic Examination ◽  
Electron Microscopic Examination ◽  
Chlamydia Psittaci ◽  
Gram Negative Bacteria ◽  
Surface Layers ◽  
Electron Microscopic ◽  
Gram Negative ◽  
Ultrastructural Studies ◽  
First Time

Electron microscopic examination of a semipurified Chlamydia psittaci 6BC strain attenuated in chick embryo yolk sac revealed for the first time two morphologically distinct small elementary bodies which differ both in the ultrastructure of their surface layers and in their buoyant densities in sucrose gradients. Also, the morphology of the surface layers of the larger reticulate forms in cell-free systems is described for the first time. Many points of difference between the surface envelopes and internal structure of chlamydial particles and those of Gram-negative bacteria are discussed.

scholarly journals Altered temporal sequence of transcriptional regulators in the generation of human cerebellar granule cells

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Hourinaz Behesti ◽  
Arif Kocabas ◽  
David E Buchholz ◽  
Thomas S Carroll ◽  
Mary E Hatten
Keyword(s):  
Granule Cells ◽  
Cerebellar Granule Cells ◽  
Affinity Purification ◽  
Brain Regions ◽  
Temporal Shift ◽  
Cerebellar Neurons ◽  
Cerebellar Granule ◽  
Human Cerebellum ◽  
Species Specific ◽  
Cerebellar Histogenesis

Brain development is regulated by conserved transcriptional programs across species, but little is known about divergent mechanisms that create species-specific characteristics. Among brain regions, human cerebellar histogenesis differs in complexity compared with non-human primates and rodents, making it important to develop methods to generate human cerebellar neurons that closely resemble those in the developing human cerebellum. We report a rapid protocol for the derivation of the human ATOH1 lineage, the precursor of excitatory cerebellar neurons, from human pluripotent stem cells (hPSC). Upon transplantation into juvenile mice, hPSC-derived cerebellar granule cells migrated along glial fibers and integrated into the cerebellar cortex. By Translational Ribosome Affinity Purification-seq, we identified an unexpected temporal shift in the expression of RBFOX3 (NeuN) and NEUROD1, which are classically associated with differentiated neurons, in the human outer external granule layer. This molecular divergence may enable the protracted development of the human cerebellum compared to mice.

Ectoderm-mesoderm interactions in relation to limb-bud chondrogenesis in the chick embryo: transfilter cultures and ultrastructural studies

Development ◽  
1981 ◽  
Vol 65 (1) ◽  
pp. 73-87
Author(s):  
Madeleine Gumpel-Pinot
Keyword(s):  
Chick Embryo ◽  
Basement Membrane ◽  
Culture Conditions ◽  
Limb Bud ◽  
Mesodermal Cell ◽  
Ultrastructural Studies ◽  
Cartilage Differentiation ◽  
Mesodermal Origin ◽  
Cell Processes

Limb ectoderm induces cartilage differentiation in mesoderm from chick embryo limb buds. Transfilter cultures have shown that this interaction requires ‘contact’ conditions and cannot take place at a distance. In vivo, a basement membrane is always present between ectoderm and mesoderm. The present paper demonstrates that the relationship between ectoderm and mesoderm is similar in vivo and in transfilter cultures. In culture conditions, the filter appears to be infiltrated by mesodermal cell outgrowths which form a continuous mesodermal cover on the filter. A basement membrane is always present between the mat of mesodermal cell processes and the ectoderm. Mesodermal cell processes are able to cross the Nuclepore filters (pore size 0·6–0·8 µm) within 15 min. After 2 h in culture, the surface of the filter opposite to the mesodermal explant is completely covered with mesodermal outgrowths. The extracellular material accumulating at the ectoderm-mesoderm interface appears to be mainly of mesodermal origin.

Effect of ethanol on the morphohistogenesis and differentiation of cerebellar granule cells in the chick embryo

Alcohol ◽  
1990 ◽  
Vol 7 (5) ◽  
pp. 419-428 ◽  
Author(s):  
A. Quesada ◽  
F.A. Prada ◽  
A. Espinar ◽  
J.M. Génis-Gálvez
Keyword(s):  
Chick Embryo ◽  
Granule Cells ◽  
Cerebellar Granule Cells ◽  
Cerebellar Granule

scholarly journals ULTRASTRUCTURAL ORGANIZATION OF CILIA AND BASAL BODIES OF THE EPITHELIUM OF THE CHOROID PLEXUS IN THE CHICK EMBRYO

1966 ◽  
Vol 29 (2) ◽  
pp. 333-345 ◽  
Author(s):  
Paul F. Doolin ◽  
Wesley J. Birge
Keyword(s):  
Chick Embryo ◽  
Basal Body ◽  
Osmium Tetroxide ◽  
Basal Plate ◽  
Ultrastructural Organization ◽  
Basal Bodies ◽  
Typical Pattern ◽  
Ultrastructural Studies ◽  
Choroidal Epithelium ◽  
Abnormal Cilia

Ultrastructural studies were performed on normal and abnormal cilia and basal bodies associated with the choroidal epithelium of the chick embryo. Tissues were prepared in each of several fixatives including: 1% osmium tetroxide, in both phosphate and veronal acetate buffers; 2% glutaraldehyde, followed by postfixation in osmium tetroxide; 1% potassium permanganate in veronal acetate buffer. Normal cilia display the typical pattern of 9 peripheral doublets and 2 central fibers, as well as a system of 9 secondary fibers. The latter show distinct interconnections between peripheral and central fibers. Supernumerary fibers were found to occur in certain abnormal cilia. The basal body is complex, bearing 9 transitional fibers at the distal end and numerous cross-striated rootlets at the proximal end. The distal end of the basal body is delimited by a basal plate of moderate density. The tubular cylinder consists of 9 triple fibers. The C subfibers end at the basal plate, whereas subfibers A and B continue into the shaft of the cilium. The 9 transitional fibers radiate out from the distal end of the basal body, ending in bulblike terminal enlargements which are closely associated with the cell membrane in the area of the basal cup. One or 2 prominent basal feet project laterally from the basal body. These structures characteristically show several dense cross-bands and, on occasion, are found associated with microtubules.

Ultrastructure of Cercarial Tails

1974 ◽  
Vol 32 ◽  
pp. 180-181
Author(s):  
Richard S. Demaree ◽  
Donald M. Wootton
Keyword(s):  
Schistosoma Japonicum ◽  
Intermediate Hosts ◽  
Suitable Host ◽  
Ultrastructural Studies ◽  
Tail Structure

Cercariae (juvenile trematodes with tails) emerge from mollusk intermediate hosts and swim toward definitive hosts or encystment objects. The locomotor power is furnished by the tail. Upon reaching a suitable host or encystment object, the tail is cast off and the cercariae penetrate and/or encyst. Ultrastructural studies of cercariae are sparse. There is even lessUltrastructural studies of cercariae are sparse. There is even less information about the tail structure; and body-to-tail morphology has been documented only for Acanthatrium oregonense and Schistosoma japonicum.

Scanning and Transmission Electron Microscopy of Endomentrium in Women Wearing TCu-380-A IUD 's

1977 ◽  
Vol 35 ◽  
pp. 666-667
Author(s):  
A. Gonzalez Angulo ◽  
R. Berlioz ◽  
R. Aznar
Keyword(s):  
Copper Wire ◽  
Uterine Cavity ◽  
Morphological Evidence ◽  
Secretory Phase ◽  
Ultrastructural Studies ◽  
Proliferative Phase ◽  
Contraceptive Devices ◽  
Transmission Electron ◽  
Intrauterine Contraceptive ◽  
Myelin Figure

Recent ultrastructural studies on endometrial tissues from women wearing copper, wire intrauterine devices have disclosed morphological evidence of impaired glycogen degradation and secretion resulting in interference with the viability of blastocysts. Reduced microapocrine secretion observed with the scanning electron microscope supports this (1). In addition, organelle modifications have been observed in the epithelial cells of these women. The changes are seen in biopsies taken in the proliferative phase of the cycle and consist of mitochondrial vacuolation and myelin figure formation. These modifications disappear in the secretory phase and therefore have been regarded as reversible (2).The aim of the present studies was to investigate surface epithelial changes as well as organelle modifications in relation to the site of contact with an IUD that releases greater amounts of copper. Endometrial tissue was obtained from the uterine cavity of four young women wearing TCu-380-A intrauterine contraceptive devices for 4-6 weeks.

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