ABSTRACT
Objective To explore the effects of high fat diet on insulin resistance ( IR) and the expression of liver insulin receptor substrate ( IRS) 1 and 2 in Tibet minipigs. Methods Ten Tibet minipigs were randomly divided into 2 groups, normal control (Ctr, n=5) group was fed with normal diet, and IR model (n=5) group fed with high fat/choles-terol diet for 12 weeks. After the establishment of pig models for 12 weeks, the body weight and body length were measured and body mass index ( BMI) was calculated, and the changes of total cholesterol ( TC) , low density lipoprotein ( LDL?C) , high density lipoprotein ( HDL?C) , triglyceride ( TG) , free fatty acids ( FFA) , fasting blood glucose ( FBG) , fasting insu?lin ( insulin) and homeostasis model assessment?insulin resistance ( HOMA?IR) were detected. Glucose tolerance test was performed, the area under the curve of glucose tolerance ( AUC) was also calculated, and the expressions of IRS?1 and IRS?2 gene and protein in liver tissue were detected. The lipid deposition, liver glycogen and pathological changes were ex?amined by pathology using oil?red O, PAS and HE staining, respectively. Results Compared with the control group, the body weight, BMI index, TC, LDL?C, HDL?C, FFA, FBG, insulin and HOMA?IR were significantly increased ( P <0. 05, P<0. 01). Intravenous glucose tolerance test showed that the curve of blood glucose and insulin levels were slowed down, while AUCglucose and AUCinsulin were significantly increased (P<0. 05, P<0. 01). Lipid deposition and liver glyco?gen were increased, and partial hepatocyte swelling, part of the nuclei disappeared or were pushed to one end, occasionally scattered infiltration of lymphocytes in the liver tissue. Furthermore, the expressions of IRS?1 and IRS?2 mRNA and protein were significantly decreased (P<0. 05, P<0. 01). Conclusions High fat diet can induce insulin resistance in Tibet minipigs. The decreased IRS?1 and IRS?2 expression in the liver may be one of the molecular mechanisms involved in the effects of high fat diet on insulin sensitivity in Tibet minipigs.
ABSTRACT
Objective To provide original reference data for oral ecosystem research, Tibet minipigs, beagle dogs, rhesus monkey, New Zealand white rabbits and Wistar rats were selected to study their respective characteristics of oral microbial mmunities and compared with normal data of humans.Methods Total DNA was extracted from the specimens of oral microbial communities of Tibet minipigs, beagle dogs, rhesus monkey, New Zealand white rabbits and Wistar rats, and used to amplify 16S rRNA V4 fragments with labeled universal primers.The diversity and structure of microbial communities from those animals were compared with that of humans using BIPES and QIIME analysis after Illumina sequencing of 16S rRNA V4 fragments.Results The richness of the oral microbial communities of humans and the five species of laboratory animals was significantly different (P <0.05).Different species of animals have their own unique oral flora, among which the oral flora of the monkey is the most similar to that of humans.Conclusions Among the five species of laboratory animals, the oral microbial communities of rhesus monkeys and humans have highest similarity. Specifically, the Fusobacterium and Porphyromonas levels of rhesus monkeys is most similar to those of humans.Our findings indicate that rhesus monkeys may be suitable animal model for studies of human oral microbial communities.Tibet minipigs may be suitable animal model for Proteobacteria studies, while beagle dogs may be appropriate for modeling of diseases related to Spirochaetes.
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Objective To amplify the encoding full-length sequence of Tibet mini-pigs myostatin ( MSTN) gene and analysis the sequence by bioinformatics software.Method The RNA of liver tissues from Tibet mini-pig was extracted, and reversely transcribed into cDNA.The gene coding region sequence of myostatin gene was amplified through RT-PCR, and then the purified product of PCR was ligated with a pMD19-T and transferred into the bacterium DH5αfor replication.The positive clones were screened and sequenced. The sequence characters were analyzed by using bioinformatics method and phylogeny evolution tree was constructed with other twelve species.Results The coding redion of MSTN gene was 1128bp, and coded 375 amino acids.The amino acid homology analysis showed that the homology rate of amino acid sequence was 99%.Conclusions Molecular phylogeny evolution indicated that it had a close relation with human, dog, banna minipig, sheep, goat, cattle, horse, chimpanzee, rat, mouse except chick and zebrafish, and the most closely related with banna minipig.
ABSTRACT
Objective To analyze the Cyt b gene sequences in Tibet mini-pigs and clarify the differences and genetic relationship with other Chinese pigs.Method The sequence of Cyt b gene was amplified from genome DNA of Tibet mini-pig,Bama miniature pigs,Guizhou xiang pigs and Wuzhishan (WZS) pigs.After sequencing,the base sequences were compared and analysed.The blood relationship tree and evolution position of Tibet mini-pig were established.Result There were 14 mutation sites between domestic pigs in China and pigs from Europe.Besides there was a significant differenee in two nucleotide site:a T→C switch in site 420 and the G→A switch in site 883 at the same time.Conclusion Chinese pigs include Bama miniature pigs,Guizhou xiang pigs and WZS pigs,have a very close blood relationship with some of Tibet mini-pigs.It has been confirmed that there is a certain genetic differentiation in the Tibet mini-pig.