Studies On Adaptive Evolution Of Visual Genes Of Lasiopodomys Mandarinus And L.brandtii

Vision is one of the important senses which animals can use to obtain information,in the higher animals,the visual system to dominate the sensory system;The information of mammals obtained by visual system occupies 70-90%,underground rodents lifelong live in light of the dark environment,degradation of visual,characterized by eye shrink or completely degraded,Mandarin vole(Lasiopodomys mandarinus)is a kind of lifelong live camp rodents,their relatives to Brandt's vole species(Lasiopodomys brandtii)which is a major relying on the ground of the ground mouse.They have similar morphological structure,but their visual system has obvious difference in handling the the dark environment,which make them become the ideal object of comparative research of rodents visual degradation.L.mandarinus as the main research object,the L.brandtii as a contrast,we sequenced the genome data of L.mandarinus and L.brandtii,geted 316 visual genes,and the results were calssified by the function: eye development?photographic?developmental genes related to visual development of the lens,and the retina.By sequencing data of vision gene coding sequence,we counted the mutated visual gene in L.mandarinus and L.brandti We detected the pseudogene in visual system.We download the sequences of homologous species from NCBI,constructing phylogenetic trees,and the different function of visual gene selection pressure analysis.The main results were as follows:1)By sequencing data acquisition vision gene coding sequence,we found that the number of L.mandarinus' s visual mutation genes in eye's development and developmental lens is greater than L.brandtii.It indicated that the two types of genes for underground life were sensitived.2)We detected the pseudogene in visual system and found a pseudogene FAT3 in the genome of L.mandarinus.3)In terms of eye structure development related genes,L.mandarinus and L.brandtii weren't detected positive selection pressure,but the blind mole rat and golden mole were detected positive selection pressure;L.mandarinus failed to form associated with rodents visual convergent evolution,that may be related to its shorted.differentiation time.4)In terms of photosensitive vision gene,L.mandarinus and L.brandtii weren't detected positive selection pressure.But L.mandarinus' s dark visual genetic evolution rate obviously accelerated,showed that it has formed corresponding adaptive evolution to the dark environment;L.mandarinus' s color vision gene were detected purifying selection.Main conclusions are as follows:L.mandarinus has the closely classification status of L.brandti.They have no significant difference on the visual genes,which could be the differentiation time is too short(about 5.2 MYA).The number of L.mandarinus' s visual mutation genes in eye developmen and developmental lens is greater than L.brandtii.It reflected the dark underground rodents early adaptation and evolution to the dark environment;L.mandarinus' s dark visual genetic evolution rate obviously accelerated,which showed that it has formed corresponding adaptive evolution to the dark environment.This research helps to reveal the underground rat visual system adaptation mechanism to the dark environment.