Chick embryo neural tissue

Fig. 1. (A) Cells labeled with Dil and DiA in the chick embryo neural plate and viewed immediately after iontophoretic applications. About four cells are labeled with Dil (red) and one cell with DiA (green). Bar is 10 gm. (B) After 48 h of development, the descendants of cells labeled as in (A) are still visible and their two colors distinct. Bar is 50 gm. (C) Motor neurons retrogradely labeled from their peripheral nerves in fixed tissue. One nerve was labeled with Dil, and the adjacent nerve with DiA. Bar is 40 gm. [See Color Plate)...

Newgreen, D.F., Ritterman, M. and Peters, E.A. (1979) Morphology and behaviour of neural crest cells of chick embryos in vitro. Cell Tissue Res. 203 115-140. 

Diazinon produces visible Type I and II ter-atisms when injected into chicken embryos. Type I teratisms (related to tissue NAD depression) included abnormal beaks, abnormal feathering, and shortened limbs. Type II teratisms, which included short and wryneck, leg musculature hypoplasia, and rump-lessness were associated with dismptions in the nicotinic cholinergic system. The severity of effects depended on embryo age and was dose related. Chick embryos (age 48 h) receiving 25.0 xg or more of diazinon/embryo had cervical notochord and neural tube malformations at 96 h, and short neck at 19 days. Wryneck occurred at doses ranging from... 

This amount corresponds to the inhibitor isolated from 3 gm of fresh tissue (trunk of chick embryo) 700 fig of DNA corresponds to the amount DNA obtained from about 3 gm of tissue. Inhibition of the vegetalizing factor is observed only in the presence of the inhibitor fraction from chick embryos or DNA, not in the presence of polyanions such as tRNA, double-stranded homo- and heteropolymeres of nucleotides or polysaccharides. The neuralizing activity of the crude protein is not inhibited by DNA (not shown in the table). 

Exchange of brain vesicles The transfer of brain vesicles from the quail to the chick and vice versa (or from a mutant to a normal chick embryo) is made using a calibrated glass micropipet. The piece of neural tissue is inserted into the groove made by the excision, with the normal rostro-caudal and dorso-ventral orientation, and then adjusted (see Note 18). 

Excision of precise pieces of the neural fold or neural plate in the chick host Very thin microscalpels (made up from insect pins or steel needles sharpened on an oil stone) are used to excise precise fragments of the folds and neural plate in 0- to 5-somite stage chick embryos in ovo. An ocular micrometer is used to measure the pieces of tissue to be removed. 

The differentiation potential of stem cells in tissues of the adult has been thought to be limited to cell lineages present in the organ from which they were derived, but there is evidence that some stem cells may have a broader differentiation repertoire. It was shown that neural stem cells from the adult mouse brain can contribute to the formation of chimerical chick and mouse embryos, and give rise to cells of all germ layers. This demonstrates that an adult neural stem cell has a very broad developmental capacity and may potentially be used to generate a variety of cell types for transplantation in different dis-eases. ... 

This protocol works well on intact embryos up to at least mouse embryonic d 12, chick Hamburger and Hamilton (3) stage 24, and zebrafish to 72h (see also Note 7 for zebrafish modifications). For older embryos, it is likely that some block dissection is required prior to fixation to keep background levels low. Alternatively, some tissues, such as the neural tube, can be dissected after performing the procedure on intact older embryos. 

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