Black Opsin Gene Regulation, The Circadian Rhythm Of The The Gansu Zokor (myospalax Cansus)

Circadian rhythm is the most common type of mammalian circadian rhythm.It is one biological functions of the day and night in order to adapt to Earth's rotation changes in the environment. The biological Clock in animals body coordinate the circadian rhythm of a variety of different tissues and organs. Animal's circadian rhythm began in the perception of the light cycles outside world. In the past we think there are only cone and rod cells two paths in the animals to perceiving the light cycles outside world. But in recent scientists research on the mice which lost cone and rod cells.they found that the third path may exist, the melanopisn geneâ†'melanopisnâ†'Suprachiasmatic nucleusâ†'circadian rhythm regulation.Melanopsin as the opsin is a new class of vitamin A. In mammals,it is mainly scattered in the retinal ganglion cells. From that date, its physiological functions have been concerned of scientists, they speculate it has a variety of physiological functions, including regulation of circadian rhythms, pupillary light response, sleep and behavior. The melanopisn gene code melanopisn, the melanopisn gene symbol is OPN4, Recent studies have found that there are two types of vertebrate opsin genes of the melanopisn: OPN4m and OPN4x. Studies have shown that OPN4x may lose prematurely in mammalian evolution because of chromosomal rearrangements.In this paper,we will determine and analyse the melanopsin gene of Myospalax cansus using conventional PCR and sequencing, Building a model of cone and rod cells loss in the use of intraperitoneal injection N-methyl-N-nitrosourea so as to interdict the introduction of cone and rod cells layer. We preliminary discuss the role of the Myospalax cansus's melanopsin gene in the regulation of circadian rhythm using the behavioral methods. the conclusions are as follows:1. Myospalax cansus's melanopisn gene is not disappear because of their special and living environment. In comparison with other species of the same genes we found: the melanopisn gene of Myospalax cansus and predicted protein sequence has highest homology with the same gene of Spalax ehrenbergi.2. The exons and introns in Myospalax cansus's melanopisn gene sequences are similar to other rodents. However, a repeat CT of 23 microsatellite sequence structure appear between the first and second exons, this sequence does't found in other species.3. In the predicted protein sequence, there are distinct difference between Myospalax cansus, Spalax ehrenbergi, Mus musculus,Rattus norvegicus and Phodopus sungorus's amino acid sequences,some species show the absence of some amino acids.4. Recording behaviour actions experiments show that Myospalax cansus animal is active day and night, it has a significant rhythm, their night activitiy time is longer than day time. Rest and sleep time account about 70% of the total time, activities time account about 30%. they are able to identify light and dark environments and have a functional biological clock to respond to the periodic light stimulation.5. There is no different in frequency and duration of rest,moving,feeding,nesting between normal and cone/rod cells layer lost Myospalax cansus. That proved retinal perceiving the light cycles outside world is not only dependent on cone and rod cells layer.The melanopsin gene and coding protein control the circadian rhythm.In short, these results above show that the melanopisn gene of Myospalax cansus don't degenerate, the function is not lost,and it has the highest homology with the same gene of Spalax ehrenbergi. Moreover, through behavioral actions recording methods.we observed in the cone/rod cells layer lost and normal Myospalax cansus at rest and sleep,moving\nesting,feeding and other important activities,there is no significant difference between the two groups. This shows that after adminis Myospalax cansus cone and rod cells lossing. retinal perceiving the light cycles outside world is not only dependent on cone and rod cells layer.As light-sensitive opsin,melanopsin may play the role of photosensitive material and play an important role in the circadian rhythm pathway. However, further studies need to prove.