The The Gansu Zokor (myospalax Cansus) Visual System Apoptosis

The significant differences shown in the evolution of the animals'visual system living in special circumstances is remarkable.As the Cansu zokor(Myospalax cansus) living in the dark underground tunnels over its life, the spatial pattern of life had a profound effect to the structure of their visual system and physiological functions. As a result of the long evolutionary adaptation, the visual system structure and function of the shape changes dramatically, the most notable of which is smaller eyes,and visual degradation. Studies show that the structure of the retina of Myospalax cansus is integrity.Why is Myospalx cansus'visual degradation and the process is still unclear.So we study Myospalax cansus for visual system to study apoptosis by use of cytology,immunohistochemistry and other methods. Results are as follows:1. From 0th day old apoptotic cells appeared in the retinal of Myospalax cansus. The apoptosis index is 26.9±0.441%. This indicates that after birth the retinal of Myospalax cansus associated with apoptosis.Apoptotic cells were in retinal rod and cone layer of the layers inward, in particular outer nuclear layer, inner nuclear layer and ganglion cell layer.This shows that the layer of rod and cone cells in each layer inward is the main visual pathway neurons.2.The apoptosis index of retinal cells gradually increased along with the dates growth of 0th,3th,5th,7th,9th,11th and 14th day old. The apoptosis index of 14th day old was the maximum, then decreased, and stabled a relative level. This shows that the apoptosis of retinal cells mainly occur within two weeks after birth and apoptotic peak appears at 14th day old, then apoptosis reduced.3. The ratio of Bax and Bcl-2 gradually increased along with the dates growth of 0th,3th,5th,7th,9th,11th and 14th day old, and the ratio of Bax and Bcl-2 in 14th day old was the largest.This shows that the degree of apoptosis gradually increased and the degree of apoptosis is the greatest in 14th day old.4. The ratios of Bax and Bcl-2 stabled a relative level. This shows that apoptosis also stable a relative level when internal environment of organism reaches stable. In addition, this result may be related with eye opening.5. The number of Bax expression of the dorsal lateral geniculate nucleus and the ventral lateral geniculate nucleus in each age section of Myospalax cansus were more than the one of other visual nucleus. This indicates that in the entire transmission process of visual information the lateral geniculate nucleus plays a extremely important role. In brief, this research indicated that apoptosis of the vision system of Myospalax cansus mainly occurres within two weeks after birth. The degree of apoptosis is the greatest in 14th day old and apoptotic peak appears at 14th day old. Then apoptosis stable a relative level.