Guizhou Miniature Pig Research Articles

Effects of metaraminol and norepinephrine on hemodynamics and kidney function in a miniature pig model of septic shock.

To compare the effects of metaraminol and norepinephrine on hemodynamics and kidney injury in the treatment of septic shock, and calculate the conversion dose ratio between the two vasopressors. This randomized controlled study was performed on 15 Guizhou miniature pigs. Septic shock was induced by fecal peritonitis in 10 animals, and 5 were used as a sham-operated group (shams). Fluid resuscitation and vasopressors were initiated 30 min after the onset of septic shock. The septic shock pigs were randomly assigned to receive one of the two drugs to restore and maintain mean arterial pressure (MAP) ≥ 65 mmHg for 3 h. Hemodynamics and heart rate were continuously monitored. There was no significant difference in MAP, heart rate, cardiac output (CO) and central venous pressure (CVP) between the two groups after treatment. No arrhythmias such as atrial fibrillation and ventricular fibrillation presented during continuous monitoring. After septic shock, the animals showed obvious kidney injury. In addition, compared with norepinephrine, the creatinine at 3 h was significantly lower with metaraminol. According to propensity score matching, the ratio of 6: 1 was considered appropriate for the dose equivalence calculation of metaraminol (μg·kg-1·min-1): norepinephrine (μg·kg-1·min-1). Metaraminol has a similar pressor effect to norepinephrine in septic shock; it does not increase heart rate and aggravate kidney injury after shock compared with norepinephrine. And our research may provide some laboratory evidence for the clinical usage of metaraminol.

Multiomic study of the protective mechanism of Persicaria capitata (Buch.-Ham. ex D.Don) H.Gross against streptozotocin-induced diabetic nephropathy in Guizhou miniature pigs

BackgroundPersicaria capitata (Buch.-Ham. ex D.Don) H.Gross (P. capitata, PCB), a traditional drug of the Miao people in China, is potential traditional drug used for the treatment of diabetic nephropathy (DN). PurposeThe purpose of this study is to investigate the function of P. capitata and clarify its protective mechanism against DN. MethodsWe induced DN in the Guizhou miniature pig with injections of streptozotocin, and P. capitata was added to the pigs’ diet to treat DN. In week 16, all the animals were slaughtered, samples were collected, and the relative DN indices were measured. 16S rRNA sequencing, metagenomics, metabolomics, RNA sequencing, and proteomics were used to explore the protective mechanism of P. capitata against DN. ResultsDietary supplementation with P. capitata significantly reduced the extent of the disease, not only in term of the relative disease indices but also in hematoxylin-eosin-stained tissues. A multiomic analysis showed that two microbes (Clostridium baratii and Escherichia coli), five metabolites (oleic acid, linoleic acid, 4-phenylbutyric acid, 18-β-glycyrrhetinic acid, and ergosterol peroxide), four proteins (ENTPD5, EPHX1, ARVCF and TREH), four important mRNAs (encoding ENTPD5, EPHX1, ARVCF, and TREH), six lncRNAs (TCONS_00024194, TCONS_00085825, TCONS_00006937, TCONS_00070981, TCONS_00074099, and TCONS_00097913), and two circRNAs (novel_circ_0001514 and novel_circ_0017507) are all involved in the protective mechanism of P. capitata against DN. ConclusionsOur results provide multidimensional theoretical support for the study and application of P. capitata.

Differentiation Potential Analysis of Bone Marrow Mesenchymal Stem Cells from Guizhou Miniature Pigs

In this study, different growth characteristics of hematopoietic stem cells and bone marrow mesenchymal stem cells were used to isolate and culture BMSCs by whole bone marrow adhesion method, and RT-PCR was used to detect cell surface markers CD29, CD31, CD34, CD44, CD71, CD73, CD90. The differentiation of osteocytes into adipocytes and osteoblasts was induced in vitro, and the differentiation ability was observed by staining with oil red O and rubinin. To investigate the isolation and culture methods of BMSCs from Guizhou miniature pigs (Sussa lvanius) in vitro, and to study their biological characteristics and potential for multi-differentiation. The results showed that a small number of adherent cells could be seen in the primary BMSCs cultured in vitro within 48 hours, and the confluent cells reached 90% in 5~6 days. The cell growth state was good, and the shape was spindle and polygonal. RT-PCR was used to detect the positive expression of CD29, CD44, CD71, CD73 and CD90 on the cell surface, and the negative expression of CD31 and CD34. Oil red O staining showed the formation of lipid droplets in the cells, and alizarine red staining showed calcium nodules in the cells, indicating that the cells isolated and cultured in this experiment had the ability of multidirection differentiation. It is consistent with the characteristics of BMSCs. The growth of BMSCs cultured in vitro was stable, and the expanded BMSCs had multidirectional differentiation potential, which was an ideal seed cell for tissue engineering.

Porcine Endogenous Retroviruses: Quantification of the Viral Copy Number for the Four Miniature Pig Breeds in China.

Domestic pigs has served not only as one of the most important economy livestock but also as ideal organ-source animals owing to similarity in anatomy, physiology, and organ size to humans. Howerer, the barrier of the cross-species transmission risk of porcine endogenous retrovirus (PERVs) blocked the pig-to-human xenotransplantation. PERVs are integrated into pigs’ genomes and cannot be eliminated by designated or specified pathogen-free breeding. PERVs are an important biosafety issue in xenotransplantation because they can be released from normal pig cells and infect human cells in vitro under certain conditions. Screening and analyzing the presence of PERVs in pig genome will provide essential parameters for pig breed sources. In China, four miniature pig breeds, such as Guizhou miniature pig (GZ), Bama miniature pig (BM), Wuzhishan miniature pig (WZS), and Juema miniature pig (JM), were the main experimental miniature pig breeds, which were widely used. In this study, PCR was performed to amplify env-A, env-B, and env-C for all individuals from the four breeds. The results revealed that PERV env-A and env-B were detected in all individuals and the lowest ratios of PERV env-C was 17.6% (3/17) in the GZ breed. Then, PERV pol and GAPDH were detected using the droplet digital PCR (ddPCR) method. As the reference of GAPDH copy number, the copy numbers of PERVs were at the median of 12, 16, 14, and 16 in the four miniature pig breeds (GZ, BM, WZS, and JM), respectively. Furthermore, the copy number of the PERV pol gene in many organs from the GZ breed was analyzed using ddPCR. The copy numbers of PERV pol gene were at the median of 7 copies, 8 copies, 8 copies, 11 copies, 5 copies, 6 copies, and 7 copies in heart, liver, spleen, lung, kidney, muscle, and skin, and the maximum number was 11 copies in the lung. The minimum number was 5 copies in the kidney as the reference of GAPDH. These data suggest that GZ breed has the lower PERVs copy number in the genome, and may be an ideal organ-source miniature pig breed for the study of the pig-to-human xenotransplantation.

Porcine skin damage threshold from mid-infrared optical parametric oscillator radiation at 3.743 µm.

There is increasing use of mid-infrared optical parametric oscillator radiation operating in the wavelength range of 3-5 µm. To expand existing damage data for skin exposure to lasers in this wavelength region, the in-vivo damage threshold at the wavelength of 3.743 µm was determined in a Guizhou miniature pig model for an exposure duration of 1.0 s. The irradiance of the laser spot was nearly Gaussian-distributed and the 1/e2 beam diameter on the animal skin surface was fixed at 0.94 and 0.88 cm along horizontal and vertical directions. Damage lesion determinations were performed at 1- and 24-hour post-exposure. The probit analysis was employed to establish the ED50 values. The ED50 expressed in peak radiant exposure for the Gaussian spot was 4.04 J/cm2 at the 24-hour post-exposure. Sufficient margin existed between the damage threshold and MPE from the current laser safety standard. The obtained data may contribute to the knowledge base for refinement of laser safety standard in the wavelength range of 2.6-1000 µm.

Regulation of left atrial fibrosis induced by mitral regurgitation by SIRT1

SIRT1 (silent information regulator 1) is a histone deacetylase. It can sense the energy level in cells and delay cell senescence, leading to resistance to external stress and improving metabolism. Mitral regurgitation (MR) is a common disease in cardiac surgery. However, there are no previous studies on SIRT1 and left atrial fibrosis caused by MR. In this study, we aimed to explore the regulatory effect of SIRT1 on left atrial fibrosis induced by MR. We used Guizhou miniature pigs to establish an MR model and a sham operation model after anaesthesia induction and respiratory intubation, and these model animals were followed for 30 months after the surgery. The differential distribution and expression of SIRT1 and collagen I in the left atrium was determined by immunofluorescence and Western blotting. Furthermore, we treated NIH3T3 fibroblasts (CFs) with resveratrol and Angiotensin II (Ang II) to analyse the specific mechanism involved in the development of myocardial fibrosis. The results showed that the MR model was successfully constructed. There were 8 pigs in the MR group and 6 pigs in the control group. In both the animal experiments and the cell experiments, the expression of collagen I in the MR group was increased significantly compared to that in the control group, while the expression of SIRT1 was decreased.

Porcine skin damage thresholds and histological damage characteristics from 1319-nm laser radiation.

.There is an increasing use of near-infrared lasers in biomedical applications operating in the spectrum between 1300 and 1400 nm. To corroborate and expand the existing safety data for skin exposure to lasers in this wavelength region, the in-vivo damage thresholds were determined in Guizhou miniature pigs for 1319-nm laser radiation. Exposure durations of 0.4, 1.0, and 3.0 s and beam diameters of 0.98 and 1.96 cm were employed. Damage lesion determinations were performed at 1- and 24 h post exposure. The Bliss probit analysis was employed to establish the damage thresholds. Histopathological studies of skin damage were performed at 48 h after irradiation to reveal the damage characteristics. The skin damage thresholds at 1 h post exposure, given in peak radiant exposure, were 35.5, 36.1, and at exposure durations of 0.4, 1.0, and 3.0 s with the spot diameter of 0.98 cm, and at exposure duration of 3.0 s with the spot diameter of 1.96 cm. At 24 h post exposure, the increased slightly. Histologically, the thermal damage characteristics at the near-threshold level included gathering of the nuclear chromatin and cell vacuolation in the epidermis and deposition of blood cells in the capillary vessels. However, at the apparently above-threshold level, the damage characteristics included obvious stretching of the nuclear chromatin in the epidermis, closing of the capillary lumen, structural change of collagen fibers, and coagulative necrosis of the hair follicle cells. The damage induced by this laser could go deep into the fatty tissue. The obtained results may contribute to the knowledge base for the damage mechanisms and expand the database for the refinement of laser safety standards in the wavelength range of 1300 to 1400 nm.

Comprehensive Profiles of mRNAs and miRNAs Reveal Molecular Characteristics of Multiple Organ Physiologies and Development in Pigs.

The pig (Sus scrofa) is not only an important livestock animal but also widely used as a biomedical model. However, the understanding of the molecular characteristics of organs and of the developmental skeletal muscle of the pig is severely limited. Here, we performed a comprehensive transcriptome profiling of mRNAs and miRNAs across nine tissues and three skeletal muscle developmental stages in the Guizhou miniature pig. The reproductive organs (ovary and testis) had greater transcriptome complexity and activity than other tissues, and the highest transcriptome similarity was between skeletal muscle and heart (R = 0.79). We identified 1,819 mRNAs and 96 miRNAs to be tissue-specific in nine organs. Testis had the largest number of tissue-specific mRNAs (992) and miRNAs (40). Only 15 genes and two miRNAs were specifically expressed in skeletal muscle and fat, respectively. During postnatal skeletal muscle development, the mRNAs associated with focal adhesion, Notch signaling, protein digestion, and absorption pathways were up-regulated from D0 to D30 and then down-regulated from D30 and D240, while genes with opposing expression patterns were significantly enriched in the oxidative phosphorylation and proteasome pathways. The miRNAs mainly regulated genes associated with insulin, Wnt, fatty acid biosynthesis, Notch, MAPK, TGF-beta, insulin secretion, ECM–receptor interaction, focal adhesion, and calcium signaling pathways. We also identified 37 new miRNA–mRNA interaction pairs involved in skeletal muscle development. Overall, our data not only provide a rich resource for understanding pig organ physiology and development but also aid the study of the molecular functions of mRNA and miRNA in mammals.

Effect of increased renal pelvis pressure on the kidney of young pigs

Objective To study what impact the elevated intrarenal pelvic pressure (IPP) may have on the childhood kidney. Methods The childhood Guizhou miniature pigs were taken as the subjects and the elevated IPP animal models were established. The IPP pressure was set at levels of 0, 30, 60, 90 mmHg (1 mmHg=0.133 kPa). After the contrast agent was administered intravenously, the left renal cortical microvasculature blood perfusion was measured using contrast-enhanced ultrasonography (CEUS) at each pressure level respectively for 5 minutes. The retrograde pyelography by CEUS was performed at each pressure level for 5 minutes on the same side after the renal cortical microvasculature blood perfusion measurement. Finally the left kidney specimens were sent for pathology. Statistical study was performed on the cortical microvasculature perfusion difference between the various IPP level of 0, 30, 60, 90 mmHg. Results In the 10 repetitions, analysis of variance suggested the Peak intensity (PI) under 4 IPP levels was not all the same statistically (F=58.947, P 0.05); AS for PI, there was statistical difference between the 60 mmHg level and 0 mmHg level (t=5.332, P<0.01). The PI between 0 mmHg level and 90 mmHg level was different statistically (t=10.507, P<0.01). Rank sum test showed that the area under curve (AUC) under four IPP levels was statistically different (χ2=28.876, P<0.01). Compared with AUC under 0 mmHg level, the AUC under 30, 60, 90 mmHg level was statistically different respectively. AS for AUC, there was statistical difference between 0 mmHg and 30 mmHg (Z=-2.497, P<0.05). there was statistical difference between the 60 mmHg level and 0 mmHg level (Z=-2.701, P<0.05). The AUC between 0 mmHg level and 90 mmHg level was different statistically (Z=-2.803, P<0.05). Both the PI and the AUC indicated that the renal blood flow decreased rapidly with the increase of IPP. The retrograde pyelography by CEUS suggested the contrast agent penetrated into the cortex in 60% of subjects, which turned out to be the cortex lacerations in cortex by pathology. The pathology showed fibrin exudation in the Bowman capsule in 70% of specimens. However, all the gross examination for the kidneys suggested no overt rupture. Conclusion Before obvious gross damage emerge the elevated IPP has impacted the kidney microscopically, physiological and pathologically. The hidden injury should be noticed by the clinical staff especially for the young children. Key words: Nephrolith; Intrarenal pelvic pressure; Kidney injury

Genome-wide profiling of Sus scrofa circular RNAs across nine organs and three developmental stages.

The spatio-temporal expression patterns of Circular RNA (circRNA) across organs and developmental stages are critical for its function and evolution analysis. However, they remain largely unclear in mammals. Here, we comprehensively analysed circRNAs in nine organs and three skeletal muscles of Guizhou miniature pig (S. scrofa), a widely used biomedical model animal. We identified 5,934 circRNAs and analysed their molecular properties, sequence conservation, spatio-temporal expression pattern, potential function, and interaction with miRNAs. S. scrofa circRNAs show modest sequence conservation with human and mouse circRNAs, are flanked by long introns, exhibit low abundance, and are expressed dynamically in a spatio-temporally specific manner. S. scrofa circRNAs show the greatest abundance and complexity in the testis. Notably, 31% of circRNAs harbour well-conserved canonical miRNA seed matches, suggesting that some circRNAs act as miRNAs sponges. We identified 149 circRNAs potentially associated with muscle growth and found that their host genes were significantly involved in muscle development, contraction, chromatin modification, cation homeostasis, and ATP hydrolysis-coupled proton transport; moreover, this set of genes was markedly enriched in genes involved in tight junctions and the calcium signalling pathway. Finally, we constructed the first public S. scrofa circRNA database, allowing researchers to query comprehensive annotation, expression, and regulatory networks of circRNAs.

Comprehensive analysis of long non-coding RNAs highlights their spatio-temporal expression patterns and evolutional conservation in Sus scrofa

Despite modest sequence conservation and rapid evolution, long non-coding RNAs (lncRNAs) appear to be conserved in expression pattern and function. However, analysis of lncRNAs across tissues and developmental stages remains largely uncharacterized in mammals. Here, we systematically investigated the lncRNAs of the Guizhou miniature pig (Sus scrofa), which was widely used as biomedical model. We performed RNA sequencing across 9 organs and 3 developmental skeletal muscle, and developed a filtering pipeline to identify 10,813 lncRNAs (9,075 novel). Conservation patterns analysis revealed that 57% of pig lncRNAs showed homology to humans and mice based on genome alignment. 5,455 lncRNAs exhibited typical hallmarks of regulatory molecules, such as high spatio-temporal specificity. Notably, conserved lncRNAs exhibited higher tissue specificity than pig-specific lncRNAs and were significantly enriched in testis and ovary. Weighted co-expression network analysis revealed a set of conserved lncRNAs that are likely involved in postnatal muscle development. Based on the high degree of similarity in the structure, organization, and dynamic expression of pig lncRNAs compared with human and mouse lncRNAs, we propose that these lncRNAs play an important role in organ physiology and development in mammals. Our results provide a resource for studying animal evolution, morphological complexity, breeding, and biomedical research.

Effects of Altered Intra-abdominal Pressure on the Upper Airway Collapsibility in a Porcine Model.

Background:Obstructive sleep apnea is strongly associated with obesity, particularly abdominal obesity common in centrally obese males. Previous studies have demonstrated that intra-abdominal pressure (IAP) is increased in morbid obesity, and tracheal traction forces may influence pharyngeal airway collapsibility. This study aimed to investigate that whether IAP plays a role in the mechanism of upper airway (UA) collapsibility via IAP-related caudal tracheal traction.Methods:An abdominal wall lifting (AWL) system and graded CO2 pneumoperitoneum pressure was applied to four supine, anesthetized Guizhou miniature pigs and its effects on tracheal displacement (TD) and airflow dynamics of UA were studied. Individual run data in 3 min obtained before and after AWL and obtained before and after graded pneumoperitoneum pressure were analyzed. Differences between baseline and AWL/graded pneumoperitoneum pressure data of each pig were examined using a Student's t-test or analysis of variance.Results:Application of AWL resulted in decreased IAP and significant caudal TD. The average displacement amplitude was 0.44 mm (P < 0.001). There were three subjects showed increased tidal volume (TV) (P < 0.01) and peak inspiratory airflow (P < 0.01); however, the change of flow limitation inspiratory UA resistance (Rua) was not significant. Experimental increased IAP by pneumoperitoneum resulted in significant cranial TD. The average displacement amplitude was 1.07 mm (P < 0.001) when IAP was 25 cmH2O compared to baseline. There were three subjects showed reduced Rua while the TV increased (P < 0.01). There was one subject had decreased TV and elevated Rua (P < 0.001).Conclusions:Decreased IAP significantly increased caudal TD, and elevated IAP significantly increased cranial TD. However, the mechanism of UA collapsibility appears primarily mediated by changes in lung volume rather than tracheal traction effect. TV plays an independent role in the mechanism of UA collapsibility.

Establishment of a hepatic cirrhosis and portal hypertension model by hepatic arterial perfusion with 80% alcohol.

To determine the feasibility and safety of establishing a porcine hepatic cirrhosis and portal hypertension model by hepatic arterial perfusion with 80% alcohol. Twenty-one healthy Guizhou miniature pigs were randomly divided into three experimental groups and three control groups. The pigs in the three experimental groups were subjected to hepatic arterial perfusion with 7, 12 and 17 mL of 80% alcohol, respectively, while those in the three control groups underwent hepatic arterial perfusion with 7, 12 and 17 mL of saline, respectively. Hepatic arteriography and direct portal phlebography were performed on all animals before and after perfusion, and the portal venous pressure and diameter were measured before perfusion, immediately after perfusion, and at 2, 4 and 6 wk after perfusion. The following procedures were performed at different time points: routine blood sampling, blood biochemistry, blood coagulation and blood ammonia tests before surgery, and at 2, 4 and 6 wk after surgery; hepatic biopsy before surgery, within 6 h after surgery, and at 1, 2, 3, 4 and 5 wk after surgery; abdominal enhanced computed tomography examination before surgery and at 6 wk after surgery; autopsy and multi-point sampling of various liver lobes for histological examination at 6 wk after surgery. In experimental group 1, different degrees of hepatic fibrosis were observed, and one pig developed hepatic cirrhosis. In experimental group 2, there were cases of hepatic cirrhosis, different degrees of increased portal venous pressure, and intrahepatic portal venous bypass, but neither extrahepatic portal-systemic bypass circulation nor death occurred. In experimental group 3, two animals died and three animals developed hepatic cirrhosis, and different degrees of increased portal venous pressure and intrahepatic portal venous bypass were also observed, but there was no extrahepatic portal-systemic bypass circulation. It is feasible to establish an animal model of hepatic cirrhosis and portal hypertension by hepatic arterial perfusion with 80% alcohol, however, the safety of this model depends on a suitable perfusion dose.

Contribution of PTHrP to mechanical strain-induced fibrochondrogenic differentiation in entheses of Achilles tendon of miniature pigs

BackgroundFibrochondrocytes are involved in entheses repair, but their response to mechanical strain (MS) is ill known. ObjectiveTo determine if parathyroid hormone-related protein (PTHrP) expression in fibrochondrocytes from fibrocartilaginous entheses is modulated by MS, and to further observe the regulatory effects of human (h) PTHrP on fibrochondrocyte differentiation. MethodsFibrochondrocytes from fibrocartilaginous entheses of Guizhou miniature pig׳s Achilles tendon were submitted or not to MS (4%, 8% or 12% cyclic tensile strain; 1Hz). Fibrochondrocytes were also exposed to: cyclopamine (Indian hedgehog (Ihh) inhibitor) (10μM), hPTHrP (10nM) or cyclopamine/hPTHrP (cyclopamine 10uM+hPTHrP 10nM). Types I, II and X collagen and PTHrP expressions were measured by real-time RT-PCR and Western blot. ResultUnder 4% strain load for 12h, types I and II collagen mRNA expressions were increased (+324% and +659%, P<0.001), while type X collagen was decreased (−89%, P<0.001). At 12%, types I and II collagen mRNA expressions were decreased (−62% and −62%, P<0.001), while type X collagen was increased (+375%, P<0.05). Under 4% strain load, PTHrP mRNA expression was increased in relation with strain duration (from 3 to 12h: +168%, P<0.001), while at 12%, PTHrP expression decreased with time (from 3 to 12h: −81%, P<0.001). Using cyclopamine for 24h, PTHrP mRNA expression was significantly decreased (−88%, P<0.05), types I and II collagen were decreased (−90% and −82%, P<0.001), and type X collagen was increased (+261%, P<0.001). ConclusionsDynamic MS modulate PTHrP expressions. Thus, PTHrP might play an important role in fibrochondrocyte differentiation, indirectly revealing a role in entheses׳ formation and repair.

CYTOLOGICAL STUDIES ON INBRED RYE

The phylogenetic relationship of five species of pigs including Guizhou miniature pig, Bama pig, Xisuangbanna inbred pig, Rongchang Pig and Landrance was studied by RAPD analysis. Thirty-nine single polymorphic primers were selected out of 190 primers. The amplified fragments of thirty-nine primers were analysed by the RAPDistance package version 1.04 and the phylogenetic tree was constructed using NJ method. The results indicated as the following: three strains of miniature pigs have close phylogenetic relationship and the phylogenetic relationship between Guizhou miniature pig and Bama miniature pig was much closer. Landrance and Rongchang pig have close phylogenetic relationship too, but their phylogenetic relationship is far from the three strains of miniature pigs.

Expression of CYP3A29 mRNA in Chinese experimental miniature pig’s livers quantitated with real-time reverse transcription polymerase chain reaction

CYP3A29 is the most important key enzyme for drug metabolism in pig's liver. Research of the characters of CYP3A29 mRNA expression in Chinese experimental miniature pig's livers is significant for evaluating it whether suitable for experimental model for drug metabolism mediated by human CYP3A4 enzyme. In this study, the levels of CYP3A29 mRNA expression in livers of Bama miniature pigs, Guizhou miniature pigs and Rongchang pigs were studied by TaqMan-mediated quantitative RT-PCR. Results indicated that the CYP3A29 mRNA expression levels in livers of these species were close to literatures of human. Levels of CYP3A29 mRNA expression were similar among livers of Bama miniature pigs, Guizhou miniature pigs and Rongchang pigs, but interindividual variations were quite large. It was suggested that Bama miniature pigs and Guizhou miniature pigs were both feasible for experimental animal model for evaluating drug metabolism in some degree.

The Degree of Inbreeding in 10 Chinese Indigenous Pig Breeds

The population inbreeding coefficients of 10 indigenous pig breeds were estimated by microsatellite markers. Results showed that: the inbreeding coefficient of Guizhou miniature pig was the highest (0.1992), and that of Hanzhong black pig the lowest (0.0727) among random mating populations. F test showed no significant difference in inbreeding coefficient among the 8 breeds (P >0.05). The inbreeding coefficient of the Guizhou miniature pig and Bama miniature pig inbreeding lines was 0.5907 and 0.4761, respectively.