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Objective: This study aims to explore the association between the density of Himalayan marmot (Marmota himalayana) and climatic factors such as temperature, precipitation, humidity, vapour pressure, sunshine percentage, wind velocity, which are closely associated with global climate change, and to provide a reference for plague prevention and control. Methods: We conducted a regression analysis to find the possible climate factors associated with the density of Himalaya marmot, and analyzed the response characters of Himalayan marmot to climate change. Results:Daily precipitation days (>=0.1 mm) and sunshine percentage were significantly associated with the density of Himalayan marmot ( p<0.01). Conclusion:Climate change was associated with the risk of plague. This phenomenon is valuable for Himalayan marmot and plague prevention. More studies are needed to understand the impact of climate change on Himalayan marmot and plague.
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Objective To investigate the 23 bp and 12 bp insertion/deletion (indel) mutations within the bovine prion protein (PRNP) gene in Chinese dairy cows, and to detect the associations of two indel mutations with BSE susceptibility and milk performance.
Methods Based on bovine PRNP gene sequence, two pairs of primers for testing the 23 bp and 12 bp indel mutations were designed. The PCR ampliifcation and agarose electrophoresis were carried out to distinguish the different genotypes within the mutations. Moreover, based on previous data from other cattle breeds and present genotypic and allelic frequencies of two indels mutations in this study, the corrections between the two indel mutations and BSE susceptibility were tested, as well as the relationships between the mutations and milk performance traits were analyzed in this study based on the statistical analyses.
Results In the analyzed Chinese Holstein population, the frequencies of two“del”alleles in 23 bp and 12 bp indel muations were more frequent. The frequency of haplotype of 23del-12del was higher than those of 23del-12ins and 23ins-12del. From the estimated r2 and D’ values, two indel polymorphisms were linked strongly in the Holstein population (D’=57.5%, r2=0.257). Compared with the BSE-affected cattle populations from the reported data, the signiifcant differences of genotypic and allelic frequencies were found among present Holstein and some BSE-affected populations (P<0.05 or P<0.01). Similarly, there were signiifcant frequency distribution differences of genotypes and alleles among Chinese Holstein and several previous reported healthy dairy cattle (P<0.05 or P<0.01). Moreover, association of genotype and combined genotypes of two indel polymorphisms with milk performance and resistant mastitis traits were analyzed in Holstein population, but no signiifcant differences were found (P>0.05).
Conclusions These observations revealed that the inlfuence of two indel mutations within the bovine PRNP gene on BSE depended on the breed and they did not affect the milk production traits, which layed the foundation for future selection of resistant animals, and for improving health conditions for dairy breeding against BSE in China.