The Gansu Zokor (myospalax Cansus) Visual System Of Apoptosis

Visual system in animal's communications occupys a dominant position,and its evolutionary adaptation has been the focus of attention.Owning to adapting to subterranean dark ecotope, morphologic structures and functions of visual system in subterranean rodents show high convergence,such as small visual organs,regressive visual ability and even no such ability,which provides ideal materials for the studies on visual system evolution of these animals.And it will assist in revealing the adaptive evolutionary mechanism of visual system of subterranean rodents.Using Giemsa-Wright staining to observe the form and the number of apoptotic cells of retinal and immunohistochemical method to measure the number of Bax and Bcl-2 of every visual nucleus in different day old groups of Myospalax cansus,and to explore the apoptosis of visual system.The 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.2.Most of apoptotic cells in the retina appeared inside photoreceptor outer segment, especially outer nuclear layer,inner nuclear layer and ganglion cell layer.This indicates that cells which inside photoreceptor outer segment are the major neurons of visual pathway.3.The apoptosis index of retinal cells gradually increased along with the dates growth of 0th, 7th 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.4.The ratio of Bax and Bcl-2 gradually increased along with the dates growth of 0th,7th and 14th day old.,and the ratio of Bax and Bcl-2 was the largest.This shows that the degree of apoptosis gradually increased and the degree of apoptosis is the greatest in 14th day old.5.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.6.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 indicates 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.