ISSN:
1432-0568
Keywords:
Interrenal tissue
;
Chick embryo
;
Freeze fracture
;
Intercellular junction
;
Macula occludens
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary The fine structural development of the intercellular junctions in the interrenal tissue of chick embryos and hens was studied using freezefracture and thin section images. In thin sections, junctional complex-like structures consisting of desmosomes and gap junctions are already seen between the interrenal cells in the 8 day-old embryo. In the freeze-fracture image, small gap junctions are already present between the interrenal cells of 8–10 day-old embryos. After 11 days of incubation, two types of gap junctions are noticeable; type I belongs to a common kind of the gap junction and type II is made of a group of many small rectangular or oval gap junctions and has an irregular meshwork configuration. Incomplete maculae occludentes, consisting of only a few linear arrays of membrane particles thought to be derived from type II gap junctions, appear on the plasma membrane around 15 days of incubation. Typical maculae occludentes belonging to a so-called “inverted type” are distinctly seen around 21 days. In view of the fact that the cell arangement of the interrenal tissue in the early stage of development is somewhat similar to that of a tubular gland, and that the macula occludens exists in the older embryo and adult hen, it is considered that the interrenal cell of this animal retains more or less an epithelial property originating from the mesodermal epithelium. No zonulae occludentes are recognizable between the interrenal cells throughout all the stages from embryo to adult.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00306487
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