ABSTRACT
Objective To clarify the expression and distribution of brain⁃derived neurotrophic factor (BDNF) in the cerebrum of plateau yaks and cattle, and to explore the relationship between BDNF function and the adaptability of altitude hypoxia. Methods Five yaks and five cattles were selected.The content and distribution of BDNF in frontal lobe, temporal lobe, parietal lobe, occipital lobe, cerebrum white matter and hippocampus of yak and cattle were analyzed by Real⁃time PCR, Western blotting and Immunohistochemistry. Results Real⁃time PCR result showed that BDNF mRNA expression in the cerebrum of yaks and cattles was highest in temporal cortex, followed by hippocampus, parietal cortex, occipital cortex and frontal cortex, and lowest in white matter. Western blotting results showed that the content of BDNF protein in the cerebrum of yaks was the highest in temporal cortex,followed by hippocampus. The content of BDNF protein in other tissues was parietal cortex, frontal cortex and cerebrum white matter, and the content of BDNF protein was the lowest in occipital cortex. The content of BDNF protein intlecerebrum of cattles was the highest in the temporal cortex, followed by the hippocampus. The content of BDNF protein in other tissues was parietal cortex, occipital cortex and frontal cortex in descending order, and the protein content in cerebrum white matter was the lowest. Immunohistochemical results showed that the positive expression of BDNF protein in the cerebrum of yaks and cattles was basically similar, mainly distributed in the granulosa cells and glial cells in the frontal cortex, temporal cortex, parietal cortex and occipital cortex, glial cells in cerebrum white matter, pyramidal cell layer and polyform cell layer in the hippocampus. There was the small amount of distribution in Martinotti cells and the molecular layer of hippocampus in the cerebral cortex. Conclusion BDNF mRNA and protein are distributed and expressed in different brain regions of yaks and cattles, but the expression level different, which is speculated to be closely related to the specific functions of different cerebrum regions. The expression level of the cerebrum of yak is higher than that of cattle except occipital cortex, suggesting that it is related to the altitude hypoxic environment. BDNF may play an important role in enhancing hypoxic tolerance and protecting internal environmental homeostasis in the process of animal adaptation to hypoxic environment.
ABSTRACT
Objective Saiga antelope is a small population inhabiting in desert and semi desert areas of national and world endangered protected animals, its wild population is extremely rare. In order to explore the correlation between hypoxic tolerance and neuroglobin (NGB) in Saiga antelope. A female Saiga antelope died of dystocia was used as the experimental animal, and the tissue samples were sampled repeatedly for 3 times to study the distribution and expression of NGB in brain of Saiga antelope in the process of adapting to hypoxia. Methods The distribution and expression of NGB in the parietal lobe, frontal lobe, temporal lobe, occipital lobe, hypothalamus, hippocampus, pear like leaf, cingulate gyrus, striatum and thalamus of Saiga antelope were detected by immunohistochemistry(IHC) and Real-time PCR. Results The result of IHC showed that NGB was positive in all parts of Saiga antelope brain, and the cells that had positive reactions in the parietal, frontal, temporal and occipital lobes of the cerebral cortex were mostly granular cells and martinotti cells. NGB was found in the granular cell layer, pyramidal cell layer and molecular cell layer in hippocampus, and the positive staining of pyramidal cell layer was the strongest. NGB positive expression in Pear like leaves and hypothalamus mainly occured in multi-type cells. NGB was expressed in the granulocytes and glial cells of cingulate gyrus, mainly in the granular cells. The positive expression of NGB in striatum was mainly located in granular cells, the positive expression of NGB in thalamus could be seen in the polymorphosis and glial cells, and the positive substance of the multi-type cells was obviously colored. The result of Real-time PCR showed that NGB was expressed in different regions of Saiga antelope brain, the highest expression in the frontal lobe of the cerebral cortex, the second in the parietal lobe, and the expression was significantly higher than that in the rest of the brain tissue (P0.05). Conclusion The expression of NGB in different regions of Saiga antelope has some selective differences in the long-term adaptation to hypoxia environment. The frontal and parietal lobes have the highest tolerance to hypoxia, followed by hippocampus, and the striatum is the weakest, which may be related to the specific functions of different regions of brain tissue, but the specific mechanism remains to be further explored.
