Popov D V, Kalistratova E N, Efimenko N N, Golichenkov V A
Arkh Anat Gistol Embriol. 1982 Sep;83(9):70-7.
The dynamics of the external cornea pigmentation in Rana temporaria L. larvae at the 22d developmental stage have been studied under conditions favourable for various course of certain morphological reactions in the pigment system. The cornea together with the surrounding skin is transferred on the dorsal surface of the larva body, and the piece of the dorsal surface skin is put instead of the cornea removed. When using the reciprocal transplantation method and preserving the organism's integrity (without disturbing melanocyte-stimulating source--namely, the hypophysis, and melatonine sources--namely, the pineal gland and the lateral eyes) the corneal pigmentation is observed on the background of perfect morphological reactions in the pigment system, while the larvae are maintained on the dark and light substrates, that is at various density of the pigment cells (120 larvae have been used). The pigmentation dynamics have been studied from the 6th up to the 20th day in total preparations. The epidermal melanophores density is estimated in 4 areas of each preparation. The melanin amount is estimated by means of the electron paramagnetic resonance-spectrometry according to the contents of free radicals expressed in relative units. A direct proportional dependence between the significantly higher melanin contents (1.5-fold) and a significantly quicker (1.5-fold) process of the corneal pigmentation is revealed, that agrees with an increasing number of the pigment cells per one unit of the body surface in the larvae maintained on the dark substrate. In the larvae maintained on the light substrate, the dependence is of a reverse character. It is probable that the factors forcing the pigmented cells, at cultivation the neural crest cells in vitro to reject from each other, affect the pigmentation of the larval cornea in vivo. If it is the case, the processes specific for the embryonal period, transgress during the cornea pigmentation at the larval stages of development.
在有利于色素系统特定形态反应呈现不同过程的条件下，研究了22日龄林蛙幼虫外部角膜色素沉着的动态变化。将角膜连同周围皮肤转移到幼虫身体的背表面，并用一块背表面皮肤代替移除的角膜。当使用相互移植方法并保持生物体的完整性（不干扰促黑素细胞来源——即垂体，以及褪黑素来源——即松果体和侧眼）时，在色素系统完美的形态反应背景下观察角膜色素沉着，同时将幼虫饲养在黑暗和明亮的底物上，即处于不同密度的色素细胞（共使用了120只幼虫）。在总共制备的样本中研究了从第6天到第20天的色素沉着动态。在每个样本的4个区域估计表皮黑素细胞密度。通过电子顺磁共振光谱法根据以相对单位表示的自由基含量估计黑色素量。揭示了黑色素含量显著更高（1.5倍）与角膜色素沉着过程显著更快（1.5倍）之间的直接比例关系，这与饲养在黑暗底物上的幼虫每单位体表色素细胞数量增加一致。在饲养在明亮底物上的幼虫中，这种关系具有相反的特征。很可能在体外培养神经嵴细胞时迫使色素细胞相互排斥的因素，在体内影响幼虫角膜的色素沉着。如果是这种情况，胚胎期特有的过程在发育的幼虫阶段角膜色素沉着期间会发生变化。
