Ghrelin gene can generate various bioactive molecules besides Ghrelin. In this review, not only the Ghrelin derived peptide were introduced, but the physiological functions, distributions and the factors which affect secretion of Des-acyl ghrelin and Obestatin were reviewed. This paper aimed to provide theoretical basis for future researches on Des-acyl ghrelin and Obestatin in the field of animal production.

This study aimed to investigate the expression of the lipid metabolism related genes, and the association between the lipid metabolism related genes and triglyceride(TG) content in intramuscular fat cells of Diannan Small-ear pigs with different H-FABP genotypes. The kit was used to determine the triglyceride(TG) content and to investigate the level of mRNA expression of lipid catabolism genes by reverse transcription quantitative real-time PCR(RT-qPCR). The results showed that significantly higher expression levels of carnitine palmitoyl transferase 1(CPT-1), lipoprotein lipase(LPL) and preoxisome proliferator-activated receptor γ(PPARγ) mRNA were found in the HH genotype individuals comparing with that in hh genotype individuals(P<0.05). The expression levels of CPT-1, LPL, PPARγ genes and TG content in intramuscular adipocytes were positively correlated. The expression of fat catabolism related genes in Diannan Small-ear pigs with different H-FABP genotypes is discrepant, the expression level of the pig with HH genotype is higher. As the lipid metabolic activity is stronger, this may increase intramuscular fat deposition relatively.

 The aim of the present study was to narrow down the range of previous genome wide association study (GWAS) , and to provide valid candidate genes for the large-scale group validation. Seven immune traits including four blood parameters(hematocrit (HCT), hemoglobin(HGB), mean corpuscular hemoglobin (MCH), mean cell volume (MCV)) and three T lymphocyte subpopulation parameters(CD4+CD8-CD3+, CD4-CD8+CD3+ and CD4+CD8-CD3+/CD4-CD8+CD3+)were measured in a porcine intercross population(Large White×Min zhu). Six haplotype blocks were built using the significant SNPs tested in the previous GWAS. Association studies between the haplotype blocks and the immune traits were performed. The result showed that the three blocks on SSC7 were significantly associated with the three T lymphocyte subpopulation parameters, the block7-3 on SSC7 was significantly associated with HGB and HCT, and the three blocks on SSC8 were significantly associated with MCH and MCV. The six blocks contained five genes ABCF1, PPP1R10, GRM4, ALB and AFP. Combination of these results, the five genes could be used as potential candidate genes for the study on immune traits.

 The objective of this study is to elucidate effects of CART on estradiol (E₂) production in vitro in follicular granulosa cells of sheep ovaries. The ovarian granulosa cells were cultured for 7 days by using the Long-term method. The cell growth status in each well was observed under a microscope after cultured of 48, 96, 144 and 168 h, respectively under different concentrations of CART and FSH. The concentration of estradiol was assayed by ABC-ELISA. After 168 h of culture, culture medium with different concentrations of FSH (5, 25 and 50 ng·mL^-1) was added, the concentration of estradiol was significantly increased. When adding 5 ng·mL^-1 FSH, the concentration of estradiol was the highest (5 694.5±40.5 pg·mL^-1). When the concentrations of FSH was 5 ng·mL^-1, with the different concentrations of CART (0.01, 0.10 and 1.00 μmol·L^-1) was added, the production of estradiol in granulosa cells were inhibited in different degrees. When the concentrations of FSH was 25 and 50 ng·mL^-1 respectively, and CART was 0.10 μmol·L^-1 in the culture media, the inhibition was significant for the production of estradiol in FSH-induced sheep ovarian granulosa cells. The generation of estradiol in sheep ovarian granulosa cells needs FSH induction. CART inhibits the estradiol production of FSH-induced sheep follicular granulosa cells in vitro.

The objective of the study was to identify whether the combination of FSH and 17-beta-estradiol regulated the mRNA expression of Cyclin D1 and Cyclin E1 in the cultured immature boar Sertoli cells. Cultured immature boar Sertoli cells were treated with the combination of 17-beta-estradiol (10^-9 mol·L^-1) and FSH (50 ng·mL^-1) and added a variety of different signaling pathway inhibitors. And Real-time PCR was applied to detect the mRNA expression of Cyclin D1 and Cyclin E1. Compared to FSH (50 ng·mL^-1) or 17-beta-estradiol (10^-9 mol·L^-1) alone, the combination of FSH and 17-beta-estradiol had no significant effect on the mRNA expression of Cyclin D1 mRNA and Cyclin E1(P>0.05). In addition, Rp-cAMP (cAMP inhibitor), Verapamil (L-type Ca²⁺ ionic channel inhibitor) or U0126 (ERK1/2 inhibitor) alone had no significant effect on the mRNA expression of Cyclin D1 and Cyclin E1 in comparison to the control group (no FSH or17-beta-estradiol) (P>0.05). However, three inhibitors could reduce the mRNA expression of Cyclin D1 and Cyclin E1 in a dose-dependent way (P<0.05, for all) when compared to the combined FSH (50 ng·mL^-1) and 17-beta-estradiol (10^-9 mol·L^-1). cAMP, Ca²⁺ and ERK1/2 were involved in the effect of the combination of FSH and 17-beta-estradiol regulating the mRNA expression of Cyclin D1 and Cyclin E1.

 To explore the effects of goat endometrial cells and sex hormones on secretion content of VEGF and IFN-γ in uNK cells. Using immortalized goat endometrial stromal cells (ESC) and epithelial cells (EEC) as an in vitro research model, the effects of the endometrial cells and sex hormones (E₂, P₄) on secretion content of VEGF and IFN-γ in uNK cells was detected by ELISA assay. When uNK cells co-cultured with EEC, estrogen alone or together with P₄ significantly inhibited the secretion levels of IFN-γ and VEGF in uNK cells (P<0.05), while the P₄ alone had no significant effect. When uNK cells co-cultured with ESC, P₄ alone or together with E₂ can significantly enhance the secretion of IFN-γ in uNK cells (P<0.05), whereas E₂ alone or together with P₄ significantly inhibited the secretion level of VEGF (P<0.05). These results indicated that the sex hormones play a role in regulatoring secretion of uNK cells co-cultured with EEC or ESC.

The objective of this study were to optimize a set of microsatellite markers in Simmental paternity testing, establish an accurate, efficient and economic paternity testing system, and provide a scientific basis for genetic evaluation and breeding of Simmental. Based on fluorescent primer and automatic sequencing techniques, genetic polymorphisms of 11 microsatellite markers were genotyped in 107 Simmental from Mongolia Ulgai. Finally 8 loci were selected as core loci to establish paternity testing system of Simmental, and paternity testing power was detected in the validation group of 10 fathers-sons and 1 no related father by likelihood-based methods. The result showed that the average of allele number, observed heterozygosity, expected heterozygosity and polymorphism information content were 11.4, 0.804, 0.828 and 0.807, respectively. Their cumulative exclusion probability reached 0.99, 0.999 5 and 0.999 998 on three different occasions. The assignment result of validation group was consistent with pedigree records and LOD varied from 9.29 to 14.66 with 95% confidence. This set of STRs have a high genetic polymorphism and an excellent value in paternity testing of Simmental, which can validate paternity efficiently with a lower cost.

 This study aimed to investigate the regulation of IGF-1 on promoting hair growth and development by studying the effect of IGF-1 on alpaca skin fibroblasts. In this study: (1)Analyzing the expression of IGF-1 and its receptor IGF-1R in the alpaca skin and cultured fibroblasts by using immunohistochemical and immunocytochemistry techniques. (2) Observing the effect of recombinant human IGF-1 in vitro with different concentrations on the proliferation and morphological changes of cultured alpaca skin fibroblasts. (3) Detecting the expression quantity of IGF-1,TGF-β1 and KGF genes in fibroblasts cultured in different IGF-1 concentrations by using QRT-PCR technology. Result: (1)The result of IGF-1 and its receptor IGF-1R protein expression was positive in the alpaca skin and cultured fibroblasts. (2) Adding IGF-1 had significant growth promoting effect on the quantity and morphology of fibroblasts, especially the addition of 10 ng·mL^-1. (3)IGF-1 could affect the gene expression of IGF-1R,transforming growth factor β1(TGF-β1) and keratinocyte growth factor(KGF) in alpaca skin fibroblasts. Compared with the control group, when IGF-1 at the concentration of 10 ng·mL^-1, the expression level of KGF was 3.332 times and IGF-1R expression level was 4.479 times. TGF-β1 gene expression level was the lowest, 0.405 times at 10 ng·mL^-1,0.813 times at 1 ng·mL^-1 and 0.434 times at 100 ng·mL^-1. The results indicate that alpaca skin fibroblasts are the target organ of IGF-1,as well as endocrinal organ.IGF-1 can induce the proliferation of alpaca skin fibroblasts, while improving expression level of IGF-1R and KGF genes, reducing the expression of TGF-β1 gene, which indicate that IGF-1 can modulate the growth and development of alpaca hair by regulating the expression of its receptor and endocrine factors.

The study aimed to study the relationship between the melanocortin 1 receptor gene (MC1R) and the coat color in rex-rabbits. According to the sequence of MC1R in GenBank，a pair of specific primer was designed to amplify the cDNA sequence of MC1R of rex-rabbits using RT-PCR technique. The results showed that the 951 bp cDNA sequence encoded 317AA, isoelectric point of MC1R protein was 9.26. Compared with the published sequence in GenBank, there were 7 transmembrane domains. Homology of nucleotide sequence and deduced amino acid was higher than 95% and 93% with cattle, horse, yak, sheep, camel, and so on, which was confirmed by the analysis of phylogenetic tree. The mutation frequency of 14 loci were higher, and 5 amino acid substitutions were detected in rex-rabbits, which lies on the transmembrane domains, which showed that the sequence of MC1R was highly conservative in mammalian. These mutation loci provide the theotrtical basis for studying the relationship between MC1R and coat color in rex-rabbits.

This experiment was conducted to evaluate the effects of various concentrations of coated ZnO on diarrhea index and intestinal morphology of weaned piglets. A total of 72 crossbred (Duroc×Landrace×Yorkshire) weaned piglets were allotted randomly, on initial BW((7.72±0.65)kg), to six groups with 4 replicates per group and 3 pigs per replicate in a completely randomized design for 28 days. Groups consisted of a low-zinc control group (LZ) fed 250 mg·kg^-1 Zn of diet as ZnO, a high-zinc control group (HZ) fed 2 250 mg·kg^-1 Zn of diet as ZnO (during 15-28 d, Zn concentration of HZ reduced to 250 mg·kg^-1) and 4 experimental groups in which coated ZnO was added at 250, 380, 570 and 760 mg·kg^-1 Zn of basal diet, respectively. The results showed as follows: 1) In 1-14 days, adding 380 and 570 mg·kg^-1 coated ZnO significantly decreased diarrhea index (P<0.05), and which had no significant differences with that of HZ；the diarrhea index, adding 510 mg·kg^-1 Zn of basal diet, was the lowest. 2) No significant increase in liver and kidney Zn concentrations were observed between groups adding 250, 380, 570 and 760 mg·kg^-1 coated ZnO (P>0.05); adding 380, 570 and 760 mg·kg^-1 coated ZnO significantly increased fecal Zn concentrations (P<0.05). 3) Adding 250, 380 and 570 mg·kg^-1 coated ZnO significantly increased duodenum villi height (P<0.05), and which had no significant differences with that of HZ (P>0.05); V/C values of duodenum, jejunum and ileum, compared with that of LZ, were greater (P<0.05)when feeding the diets adding 570 or 760 mg·kg^-1 coated ZnO. It is concluded that adding 380-570 mg·kg^-1 coated ZnO, as pharmacological concentrations of ZnO does, can protect intestinal morphology and decrease diarrhea effectively, moreover,can save Zn source and reduce environmental pollution.

The experiment was conducted to study the effects of different surface tension (ST) of fermentation liquid and specific surface area (SSA) of neutral detergent fiber (NDF) on the processes of in vitro fermentation and to explore the mechanism. Three types of SSA (3.27, 3.73 and 4.44 m²·g^-1) of NDF distracted from rice straw, and four levels of ST (54, 46, 43 and 36 mN·m^-1) were assigned to a 3 × 4 factorial design. The samples were collected to determine the NDF disappearance rate, pH and ammonia nitrogen (NH₃-N) concentration at the fermentation time of 6, 12, 24, 36, 48 and 72 h, and to determine the total gas production at each fermentation time. The results as following: The gas production of fast and slow degradable fraction increased (P<0.001) with the decreasing of SSA of NDF particle. The NDF disappearance rate increased (P<0.001), but pH and the NH₃-N concentration decreased (P<0.001) as the increasing SSA of NDF. ST had significant (P<0.01) effect on gas production, pH and NH₃-N concentration and NDF disappearance rate. Gas production of fast fermentable parts and lag time significantly (P<0.001) decreased, but gas production of slow fermentable parts significantly (P<0.001) increased with the decreasing of ST, NDF disappearance rate had been prominently decreased (P<0.001), but the pH had been increased when ST below to 36 mN·m^-1. Those results indicate that substrate’s specific surface area and liquid surface tension directly influenced in vitro fermentation characteristics of fiber, and the rumen fermentation and feedstuff utilization could be regulated by adjust the SSA of substrate and the ST of rumen liquor.

A novel electrochemical immunosensor for sensitive detection of avian influenza virus (AIV) H5N1 was described. A graphene oxide (GO) carrying H5N1-polychonal antibodies (PAb-H5N1) and Bovine serum albumin (BSA) were used as signal amplification materials. On the basis of the signal amplification strategy of PAb-H5N1-GO-BSA nanocomposite, the developed immunosensor showed a 256-fold increase in detection limit compared to the immunosensor without PAb-H5N1-GO-BSA nanocomposite amplification. The developed method could detect 2^-15 HA unit·50 μL^-1 H5N1 with a linear calibration range from 2^-15 to 2^-8 HA unit·50 μL^-1. This immunosensor has a good specificity and high sensitivity, and it is promising for rapid detection of pathogenic microorganisms.

At the beginning of 2012, a disease occurred in a goat farm in Heze City and two strains of pathogen were isolated from the infected goats. In order to identify the infected bacteria and analyze the homology between isolated strains and heterologous strains, bacteria were isolated from infected goats internal organs and were identified by morphologic characteristics, cultural characteristic, biochemistry test, serologic test and pathogenicity test; A pair of universal primers was designed to amplify 16S-23S rRNA ISR (intergenic spacer region) gene and three visible straps were observed when PCR products were cut by HinfⅠ, at the same time the main strap of PCR straps was sequenced and analyzed by phyletic evolution. The results showed that isolated strains were Proteus mirabilis; the result of PCR-RFLP of isolated strains and Proteus mirabilis from rabbit and chicken was the same; The homology was 94.8% between isolated strains from goat and Proteus mirabilis from rabbit, 96.0%-98.2% between isolated strains from goat and Proteus mirabilis from chicken and 96.9% between isolated strains from goat and Proteus mirabilis from human. Therefore primary bacterium of the case was Proteus mirabilis; the genetic relationship of isolated strains with Proteus mirabilis from rabbit, chicken and human was closer.

The present study was undertaken to screen antigen proteins with high specificity and sensitivity in Mycoplasma hyopneumoniae. Swine were vaccinated intramuscularly and intrapulmonary with Mycoplasma hyopneumoniae inactivated vaccine and attenuated M. hyopneumoniae 168 strain live vaccine. Serum samples were collected on 7, 15, 30 and 56 d post immunization. Antibody occurrence was detected using each and all of P97R1, P36, P46, DnaK proteins as specificity antigenic protein, respectively. And the further compare detection test was investigated. The results showed that P36 and P97R1 proteins based ELISA could detect relatively high maternal antibody levels; Antibody occurrence detected by DanK protein based ELISA was in accordance with that of P46 protein, and both had long-term high antibody titers. Compared with other proteins, mix proteins antigen based ELISA could detect high antibody titers on 56 d after immunization. Mix proteins based ELISA was satisfactory and high complicated with IDEXX antibody detection kit. But it has higher sensitivity than IDEXX antibody detection kit. And antibody occurrence detected by mixed proteins based ELISA was more in accordance with antibody occurrence regularity than IDEXX antibody detection kit. The results showed that the mix proteins based ELISA has high detection sensitivity, which indicated that this method can more accurately monitoring the infection status and animal immune status.

The present study was undertaken to compare and analyze the microscopic characteristics of helminth eggs of ruminants, such as cattle and sheep, and realize the digital description of helminth egg images. Nine kinds of identified helminth were selected for obtaining abundant eggs from cloaca in this study. To establish helminth egg images database, the mature eggs were selected and photographed by biological microscope. The sizes and shapes of all helminth eggs were compared and the Pseudo-Jacobi-Fourier Moments were used for feature extraction and digital description. The result showed that, the length and width of different helminth eggs all have significant differences, the invariant moment values of the same kind of eggs were almost the same, but different kinds of eggs revealed large difference in the invariant moment values. The reconstruction images of the helminth eggs is satisfied, and they are much similar to original images, hence, the PJFM’s is suitable to extract the key feature point of eggs images. Therefore, our study can provide important technologic basis for digitization description and intellegent identification of helminth eggs.

To investigate the role of RBP4 during the differentiation of porcine preadipocytes and the biological function of RBP4, we constructed porcine RBP4 lentivirus interfering vector, then infected the porcine preadipocytes. The changes in morphology and gene expression levels were studied to evaluate the effects of RBP4 expression on preadipocyte differentiation by BODIPY, Oil Red O staining and real-time PCR analysis. The results showed that RBP4 lentivirus interfering vector was constructed correctly, virus titer was 6.5×10⁷ pfu·mL^-1. RBP4 mRNA and protein expression was remarkably reduced by approximate 60% in porcine preadipocytes infected with shRBP4. Moreover, preadipocytes differentiation was promoted and the mRNA expression levels of PPARγ, SREBP-1c and aP2 were increased in adipocytes by knocking down of RBP4. Therefore, adipogenic differentiation of porcine preadipocytes are inhibited by RBP4, which would help the further exploration of the biological mechanism of RBP4 during the adipogenesis.

The aim of the study was to establish the expression profiles of miR-200 family in mammary gland tissues of Xinong Saanen dairy goats, and to analyze the correlation between miR-200 family and milk composition. Real-Time qPCR was used for detecting the expression of miR-200 family in mammary gland during mid-lactation and dry period. Pearson’s correlation coefficient analysis was used to determine the correlations of different miR-200 family members and goat milk composition. MiRanda, TargetScan 6.2, RNAhybrid, and PITA software were used for predicting the target genes of miR-200 family. Results showed that the expression levels of all miR-200 family members during mid-lactation were significantly higher than that during dry period (P < 0.01). Correlation analysis showed the significant correlations between miR-200a and miR-141 (P<0.05), and miR-200b and miR-200c (P<0.01). Furthermore, the expression levels of miR-200c significantly correlated with the contents of goat milk protein, solids-not-fat (SNF), and Freezing point depression (FPD) (P<0.05). We also found STAT4, a key regulator for milk fat synthesis, was a predicted target genes of miR-200a and miR-141. We concluded that miR-200 family might regulate milk protein and fatty acid synthesis in lactating goats.

To explore the effect of flavonoids from flowers of Paulownia tomentosa on the ultrastructure of spleen and thymus in mice, 120 Kunming mice were randomly divided into four groups (n = 30, half male and half female). Using daily intragastric administration of flavonoids from Paulownia tomentosa flower according to the weight to establish the experimental animal model: Mice in flavonoid group Ⅰ, flavonoid group Ⅱ and flavonoid group Ⅲ were drenched (once daily for 28 days) with 40, 120 and 360 mg·(kg·d)^－1 flavonoid, respectively. Mice in control group were gavaged with equal volume PBS containing 0.5% CMC-Na. On the 28^th day of the treatment, spleens and thymuses were collected and organ index was calculated. Proliferation and transformation of spleen lymphocytes induced by ConA were determined by MTT method. Phagocytosis of peritoneal macrophages was tested by neutral red test. The ultrastructure of spleen and thymuses were observed through scanning electron microscope. The results showed that different doses of flavonoids from Paulownia tomentosa flowers can significantly improve the thymus and spleen index and lymphocyte proliferation response (P<0.05) in a dose-dependent manner. Compared with the control group, the number of mature lymphocytes in mice spleen and thymus increased significantly in the three flavonoid-treated groups, especially in high dose group. The results suggest that flavonoids from Paulownia tomentosa flowers affect the ultrastructure of spleen and thymus by increasing immune organ quality, immune organs mature lymphocyte number. In addition, lymphocyte proliferation response, flavonoids from Paulownia tomentosa flowers has a certain regulation effect on the immune function in mice by reinforcing the T lymphocyte proliferation response of spleen and thymus to the cellular immune function.

 In order to explore the relationship of regulatory pathways between progesterone’s endocrine regulation and autonomic nerve’s neuroregulation on gastrointestinal function, the distribution of progesterone receptor (PR) in celiac superior mesenteric ganglion of female goat was detected by immunohistochemical SP method. The results showed that PR immunoreactive products distributed widely in the celiac superior mesenteric ganglion of female goat, and mainly in nerve cells. The cell membrane of neurons was brown as strong positive, and cytoplasm was strong or moderate positive. 43.40% neurons’ karyoplasm was tawny, but the nucleolus was clear vacuoles; 56.60% neurons’ karyoplasm had no staining, but nucleolus was moderate positive. Image analysis showed that PR in the nerve cells was extremely significant compared with other non-nerve cells (P＜0.01). The result proved that the neurons in celiac superior mesenteric ganglion were the main target cells of progesterone, and PR in celiac superior mesenteric ganglion might be the network node to coordinate the endocrine regulation of progesterone and neuroregulation of autonomic nerve on gastrointestinal function.

The aim of this study was to study the ultrastructure of tibia growth plate in broiler chickens with a thiram (Tetramethylthiuram disulfide)-feeding procedure at the different stages. Seven-day-old AA broiler chickens were fed a regular diet containing thiram 100 mg·kg^－1 for 48 h, then were dissected quickly, and growth plates were fixed in 2.5% glutaric dialdehyde solution in 4 ℃ when they were 8, 9, 13 day-old. The ultrastructure of chondrocyte was observed by transmission electron microscope. The results showed that proliferative chondrocytes were slightly necrotic, increased numbers of swollen mitochondrion appeared electron-dense particles and vesiculated cisternae of the endoplasmic reticulum were in rounding at 8 day-old, and swollen mitochondrion, breaked and dilated cisternae of the endoplasmic reticulum were more severe at 9 day-old; plasmolysis and doubtful apoptotic prehypertrophic chondrocytes were discovered at 8, 9 day-old, moreover, lighten necrotic prehypertrophic chondrocytes with complete cellular structure and increased secretory vacuoles with fine particles of proteoglycans emerged at 13 day-old. In conclusion, both proliferative cells and prehypertrophic chondrocytes of growth plates were damaged by thiram in a short time, especialy to prehypertrophic chondrocytes. We supposed that this changes would influence normal chondrocyte development. It was possible that thiram could disturb the energy metabolism and cellular signal transduction which confused the cell cycle, and resulted in tibial dischondroplasia.

 To explore the relationships of the degree of mastitis, total bacteria count, and bacterial infection pattern with milk composition and somatic cell count, the identifying medium and plate counting method were used for identification of bacteria and total bacteria count, and subclinical mastitis and dairy herd improvement (DHI) were also tested in 187 dairy cows with different degree of mastitis in this experiment. The results showed that: 1) Patterns of bacterial infection exerted insignificant effects on somatic cell count, milk protein and fat rate (P＞0.05), but had significant impact on the determination of daily milk yields (P<0.05); 2) Total bacteria count had no significant effect on protein content (P＞0.05), but had extremely significant effect (P<0.01) on daily milk yield, milk fat content and somatic cell count; 3) Under the same bacterial infection pattern, total bacteria count had significant impact (P<0.05) on the determination of daily milk yields, somatic cell count, milk protein and fat content; 4) the degree of mastitis had significant effect (P<0.05) on somatic cell count, daily milk yield, milk fat and protein content, and the total bacteria count; 5)The somatic cell count had extremely significant effect (P<0.01) on daily milk yield milk fat and protein content. These findings demonstrated that pattern of bacterial infection exerted insignificant effects on somatic cell count, and the degree of mastitis and somatic cell count had significant effect on milk component. We could use somatic cell count and the total number of colonies to monitor the mastitis risks and the possible changes in milk composition.

Platycodon grandiflorum has "direct medicines ascending" action documented in the ancient Chinese medicinal book. For studying medicinal direct theory of Platycodon grandiflorum, we have added Platycodon grandiflorum on chicken’s drinking water, and then injected tilmicosin in order to investigate the effect of Platycodon grandiflorum on concentration of tilmicosin residues in lung tissues. We have offered drinking water containing different concentrations of Platycodon grandiflorum to experimental chickens for 4 weeks, and then the control group and experimental group were injected tilmicosin. Tilmicosin was extracted from lung tissues and detected by using high performance liquid chromatography (HPLC). The results showed that Platycodon grandiflorum can improve tilmicosin concentration in chicken lung tissue. These results conformed that Platycodon grandiflorum does have "direct medicines ascending" property.

 The study was to investigate the regulation mechanism of miR-21 in skeletal muscle development. Using computational target prediction programs, we identified TSC1 and PPP3CA genes as the potential targets of miR-21 which can specify bind to their 3′ UTR regions. The 3′UTR regions of these two genes were amplified by PCR from Tongcheng pigs genomic DNA. The PCR productions were digested by double digestion with Not I and Xho I. We got the pCHE-TSC1-3′UTR and pCHE-PPP3CA-3′UTR vectors after digested products were ligated into the vector psiCHECK with the dual-luciferase gene. These vectors were transfected into porcine iliac endothelial cell line (PIEC) and porcine kidney epithelial cell line (PK15), and then the luciferase activity was tested by a dual-luciferase reporter assay. The results showed that the luciferase activity of experimental group was significantly lower than that of the control（P<0.05）both in PIEC and PK15. This study demonstrated that TSC1 and PPP3CA were the possible target genes of miR-21 and provides basic for further research the function of miR-21.