Transgenic Pigs Carrying a Synthesized Fatty Acid Desaturase Gene Yield High Level of ω-3 PUFAs

Polyunsaturated fatty acids （PUFAs） are essential for normal growth in mammals, especially the ω-3 PUFAs, which play important roles in preventing several life-threatening diseases, such as coronary heart disease and diabetes. In this study, we aimed to investigate whether the sFat-1 gene from Caenorhabditis briggsae could be functionally expressed in transgenic pigs, and whether the transgenic could synthesize high quality ω-3 PUFAs endogenously. In this study, a gene construct consisting of CMV promoter and 1.9 kb cDNA of ω-3 fatty acid desaturase gene （sFat-1） from C. briggsae was injected into the male pronucleus of pig embryos by microinjection. The piglets were screened for the transgene by PCR, Southern blot and reverse transcription-PCR analysis. Pigs that give positive results were mated with wild-type pigs to produce the next generation and the transmission of transgene was examined by PCR analysis. Fatty acids compositions of various tissues in the transgenic pigs were then analyzed by gas chromatograph. A total of 878 embryos were transferred into 42 recipients, among which 29 successfully got pregnant and gave birth to a total of 162 piglets, and 8 of them were identified to be transgenic. Fatty acid compositions in the transgenic pigs were altered, and the levels of ω-6：ω-3 ratios were decreased from 14.53 in the control to 2.62 in Fat-1 transgenic pigs. A number of primary sFat-1-transgenic pigs were bred in this study, which lays the foundation for cultivation of new varieties of transgenic pigs.

Study of Swine Leukocyte Antigen Class I-3 (SLA-3) Gene for Inbreeding Wuzhishan Pig

To elucidate the structure of SLA-3 alleles on inbred line of Wuzhishan pig （WZSP） population, we examined the partial exon 1, completed exon 2, and partial exon 3 of SLA-3 loci using the reverse transcription-polymerase chain reaction （RT- PCR） and the sequencing-based method in 32 WZSPs. According to pedigree and amplification results, PCR products of 8 WZSPs were selected to clone and sequence. Nine different nucleotide sequences were obtained. After comparing the DNA and protein sequences of the WZSPs SLA-3 alleles with the published GenBank SLA sequences, it was found that the SLA-3 alleles in WZSPs were all novel, but there were very few variations among them. Comparision of SLA-3 and HLA-A protein sequences indicated that there was more sequence homology. Meanwhile, the construction of a phylogenetic tree using the nucleotide sequences of 23 SLA-3 alleles and 1 HLA-A allele represented that the WZSP population owns its unique genetics resource. In this study, the alleles of SLA-3 on WZSP group were successfully detected and analyzed, which provided the firm basis on the genotype of SLA-3 for breeding specific haplotypes WZSPs.

Pig Liver Esterase-catalyzed Hydrolysis of Three Diesters of meso-Bicyclic Dicarboxylic Acid and Three Tetraesters of Tetrahydrofuran -2,3,4,5-tetracarboxylic Acid

Three diesters of exo- syn-meso-oxabicyclo (2, 2, 1 ) -hept- 5- ene- 2, 3- dicarboxylic acid and three tetraesters of tetrahydrofuran-2, 3, 4, 5-tetracarboxylic acid were synthesized and tested with enantioselective hydrolysis catalyzed by pig liver esterase(PLE). The results of the PLEcatalyzed hydrolysis were discussed.

Effects of Electrical Stimulation During Absolute Refractory Period on Contraction and Relaxation of Cardiomyocytes from Normal Guinea - pigs

Objectives To investi-gate the effect of electrical stimulation during absolute refractory period on contraction and relaxation of ventricular myocytes from normal guinea - pigs. Methods The guinea - pig ventricular myocytes were obtained by enzyme digesting, and the extent of its contraction and relaxation and Ca2+ transient were recorded through the motion edge detection system. Results (1) The contracting extent of guinea - pig ventricular myocytes increased 15.45±6.48% , and the peak velocity of shorting (contraction) and the peak veloci ty of relengthening (relaxation) increased 15.97 ± 8.37% and 21. 63±8. 06% respectively (n = 10); (2) The extent of ventricular myocytes fluorescence ra tio(360/380) (F360/F380) increased 22. 55±9. 08%, and the peak velocity of ventricular myocytes F360 /F380 increased 36. 75 ± 9. 77% and 23. 62±4. 47% during shorting and relengthening respectively (n = 6) . Conclusions Appropriate electrical stimulation may strengthen the contracting and relaxing function of normal guinea - pig ventricular myocytes.

Morphology and Chemical Phenotype of the Ovarian Intrinsic Neurons in Neonate and Sexually Mature Reproductive Guinea Pig

Introduction: The existence of ovarian intrinsic neurons is well established. However, the morphology and chemical phenotype are not completely characterized and are even unknown for some species used in medical research. The purpose of this work was to determine the morphology and chemical phenotype of intrinsic neurons of the guinea pig ovary at two ages: neonates (0 days old) and sexually mature reproductive animals (90 days old). Materials and Methods: For the morphological analysis, we employed the modified Golgi-Cox impregnation technique. For the chemical phenotype, we used immunohistochemistry and the following antibodies;tyrosine hydroxylase (TH), calcitonin gene-related peptide (CGRP), transient receptor potential type 1 (TRPV1), neuron-specific nuclear protein (NeuN) and proto-oncogene product of the cFos gene (cFos). We also used enzyme histochemistry for NADPH-diaphorase detection. Results: The number of intrinsic neurons in the neonate ovary was low in comparison to the adult guinea pig ovary. The intrinsic neurons were located in the cortex and the ovarian medulla;some were isolated or clustered, forming ganglia, and others were interconnected and formed networks. The neurons were small, medium or large. In the cortex of neonate vs adult ovaries, the small and medium neurons comprised 23% vs 36% and 5.2% vs 11.6%, respectively. In the medulla, the percent of the same neurons was 10.1% vs 10.1% and 1.1% vs 2.2% in the neonate and adult, respectively. In both cortex and medulla < 1% were large neurons at two ages. Also, the neurons were rounded, fusiform or multipolar. In the cortex, they were 12.7% vs 20.9%, 14.9% vs 24.2% and 1.1% vs 3.0%, respectively. In the medulla, the percent of small vs medium neurons was 6% vs 7.1% and 4.1% vs 4.8% in the neonate and adult ovary, respectively, and <1% were large neurons at both ages. The chemical phenotypes were in the neonate and adult: TH/NeuN-positive neurons, 16.3% vs 26.5%;CGRP/NeuN, 13.5% vs 35.8%;TRPV1/NeuN, 10.2% vs 38.6%;and cFos/NeuN, 4.6% vs 5.4%, respectively.The percent of NADPHd-positive cells in the cortex was 9.5% vs 25.1% and 3.2% vs 62.2% in the medulla in the neonate and adult, respectively. Conclusion: Altogether, these data showed that the number of ovarian intrinsic neurons was low at birth and increased in the sexually mature reproductive guinea pig. The chemical phenotype was rich and peptidergic, catecholaminergic and nitrergic in nature and positive for cFos immunoreactivity. Therefore, intrinsic neurons can be chemical sensors inside of the gonad and transmit signal to the central nervous system.

浅谈盈亏平衡分析在养猪企业投资决策管理中的应用

养猪企业要生存、有效益,投资是关键,特别是规模猪场,一是投资分散、周期长、风险大、效益差。开始饲养投资比例小,到商品猪出售时投资达到最高,从仔猪购进到产仔再到养成出栏的育肥猪,需要一年的时间。二是投资时机与商品猪市场呈周期性的变化很难把握,过去是五年、三年一个周期,现在是几个月。在这种环境下养猪企业投资如何科学决策,本文认为利用盈亏平衡分析是养猪企业投资一种比较好的方法。

African Swine Fever Virus MGF-110-9L-deficient Mutant Has Attenuated Virulence in Pigs

African swine fever virus(ASFV)is the etiological agent of African swine fever(ASF),an often lethal disease in domestic and wild pigs.ASF represents a major threat to the swine industry worldwide.Currently,no commercial vaccine is available because of the complexity of ASFV or biosecurity concerns.Live attenuated viruses that are naturally isolated or genetically manipulated have demonstrated reliable protection against homologous ASFV strain challenge.In the present study,a mutant ASFV strain with the deletion of ASFV MGF-110-9L(ASFV-D9L)was generated from a highly virulent ASFV CN/GS/2018 parental strain,a genotypeⅡASFV.Relative to the parental ASFV isolate,deletion of the MGF-110-9L gene significantly decreased the ability of ASFV-D9L to replicate in vitro in primary swine macrophage cell cultures.The majority of animals inoculated intramuscularly with a low dose of ASFV-D9L(10 HAD50)remained clinically normal during the 21-day observational period.Three of five ASFV-D9L-infected animals displayed low viremia titers and low virus shedding and developed a strong virus-specific antibody response,indicating partial attenuation of the ASFV-D9L strain in pigs.The findings imply the potential usefulness of the ASFV-D9L strain for further development of ASF control measures.