An autoradiographic study of DNA synthesis in the retina of chick embryo
1986
Gunarso, W. (Institut Pertanian Bogor (Indonesia). Fakultas Perikanan) | Nagata | Shimizu | Segawa
The incorporation of 3H-thymidine into DNA was examined in the chick embryo retina in early development during the period of the optic vesicle formation (day 2) to prior formation of the basic layers of the retina (day 7) by means of both light and electron microscopic autoradiography. Labelling index with 3H-thymidine reached the maximum value on day 2 and declined thereafter. The pattern of localization of labelled cells and average grain counts were compared in three different regions of the retina; the anterior, the equatorial and the posterior region. On day 2, more labelled cells were found in the posterior region in comparison with the other two regions. Most of the labelled cells occupied the outer portion of the retinal layer through out the retina. The labelling pattern then changed on day 3, where the labelled cells were predominately found in the anterior and less in the posterior region. On day 4, the presence of the labelled cells in the anterior and equatorial regions were still dominant. In these two regions, more labelled cells occupied the outer portion of the retinal layer, while in the posterior region they switched into the inner portion of the retinal layer. The results of the average grain count of cells labelled with 3H-thymidine were inherent with the labelling pattern of each embryo group examined.
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