海洋源性胶原蛋白用做组织工程材料的研究进展

胶原蛋白因具有高生物相容性、可降解性、易得性及低免疫原性等,现已作为理想的生物材料被广泛应用于组织工程器官/组织的体外构建。目前使用的胶原蛋白主要来源于陆生哺乳动物,但该来源存在宗教限制及人畜共患疾病传染风险。海洋源性胶原蛋白(Marine collagen,mCOL)不但在氨基酸组成和生物相容性方面与陆生动物胶原蛋白高度相似,更胜在来源广泛、易于提取、不存在病原微生物污染且具有稳定的化学和物理特性等。然而目前对于其作为生物材料在组织工程中的应用尚没有系统的论述。本文对mCOL的来源、特性及提取工艺进行了概述,并对其目前作为生物材料在组织工程中的应用进展进行了重点阐述,同时展望了mCOL作为理想器官和组织再生材料来源的可能性,为开发利用mCOL应用于组织工程器官和组织再生提供建议与参考。

Establishment and Characterization of a New Cell Line from the Kidney of Spotted Halibut Verasper variegates

A cell line, SHK, was derived from the kidney of spotted halibut Verasper variegates. The cell line was subcultured more than 40 passages in minimum essential medium （MEM） supplemented with fetal bovine serum （FBS） and 10 ng ml4 basic fibroblast growth factor （bFGF）. Cell morphology from primary culture and subculture was observed continuously by microscopy. The SHK cell line consisted predominantly of fibroblast-like cells. The cell line was able to grow between 20℃ and 30℃ with the optimum growth at 24℃ and with a reduced growth between 12℃ and 20℃. The growth rate of the cells increased as the proportion of FBS increased from 10% to 20% at 28℃ with optimum growth at the concentration of 20%. The doubling time of the cells was determined to be 44.8 h. Chromosome analysis revealed that 52% of the SHK cells maintained a normal diploid chromosome number （2n=46）. The cells were successfully transfected with green fluorescent protein （GFP） reporter plasmids and the expression of GFP gene in the cells indicated the possible utility of the cells in gene expression studies. The cells were infected by lymphosystis disease virus （LCDV） and found to be susceptible to the virus in cytopathic effect （CPE） observation. The infection was confirmed by PCR and electron microscopy experiments, which proved the existence of the viral particles in the cytoplasm of the virus-infected cells.

Establishment and Characterization of a New Marine Fish Cell Line from Ovary of Barfin Flounder(Verasper moseri)

A novel continuous ovary cell line from barfin flounder(Verasper moseri)(BFO cell line) was established with its primitive application in transgenic expression demonstrated in this study. Primarily cultured cells grew well at 22℃ in Dulbecco's modified Eagle medium/F12 medium(DMEM/F12, 1:1; p H 7.2) supplemented with 20% fetal bovine serum(FBS), carboxymethyl chitooligosaccharide, basic fibroblast growth factor(b FGF) and insulin-like growth factor-I(IGF-I). The primary BFO cells in fibroblastic morphology proliferated into a confluent monolayer about 2 weeks later, and were able to be subcultured. Impacts of medium and temperature on the growth of the cells were examined. The optimum growth was found in DMEM/F12 with 20% FBS and at 22℃. The BFO cells can be continuously subcultured to Passage 120 steadily with a population doubling time of 32.7 h at Passage 60. Chromosome analysis revealed that 72% of BFO cells at Passage 60 maintained the normal diploid chromosome number(46) with a normal karyotype of 2st+44t. The results of gene transformation indicated that green fluorescence protein(GFP) positively expressed in these cells after being transformed with pc DNA3.1-GFP. Therefore, a continuous and transformable BFO cell line was successfully established, which may serve as a useful tool for cytotechnological manipulation and transgenic modification of this fish.

Development of an Inactivated Iridovirus Vaccine Against Turbot Viral Reddish Body Syndrome

Turbot(Scophthalmus maximus L.) reddish body iridovirus(TRBIV) was propagated in turbot fin cells(TF cells) and inactivated as the TRBIV vaccine with its protection efficiency evaluated in this study.TF cells were cultured in 10% bovine calf serum(BCS)-containing MEM medium(pH7.0) at 22℃,in which TRBIV propagated to a titer as high as 105.6 TCID50 mL-1.The TRBIV was inactivated with 0.1% formalin and formulated with 0.5% aluminum hydroxide.The inactivated vaccine caused neither cytopathogenic effect(CPE) on TF cells nor pathogenic effect on turbots.After being administered with the vaccine twice via muscle injection,the turbot developed high-tittered TRBIV neutralizing antibodies in a dose-dependent manner.The vaccine protected the turbot from dying with an immunoprotection rate of 83.3% as was determined via subcutaneous vaccination in the laboratory and 90.5% via bath vaccination in turbot farms,respectively.The inactivated vaccine was very immunogenic,efficiently preventing tur-bot from death.It holds the potential of being applied in aquaculture.

Development of 57 Novel Polymorphic Microsatellite Markers in Half-Smooth Tongue Sole(Cynoglossus semilaevis)

Half-smooth tongue sole (Cynoglossus semilaevis) is a promising species for aquaculture in China.The wild population of C. semilaevis is under threat from environmental factors. Microsatellite markers are very suitable for assessing genetic diversity. Four microsatellite-enriched libraries of half smooth tongue sole (Cynoglossus semilaevis) were constructed,from which 57 polymorphic microsatellites were isolated and characterized.The polymorphism of these microsatellites was assessed by genotyping in 30 individual fish.The number of alleles ranged from 2 to 11, with an average of 4.614 alleles per locus.The values of observed and expected heterozygosities ranged from 0.1000 to 1.0000 and from 0.0966 to 0.8847 respectively. Polymorphism information content (PIC) ranged from 0.0905 to 0.862.These markers would be useful for population structure assessment,genetic linkage map construction and parentage analysis for this species.

从贫困脆弱性到发展韧性:农户家庭生计策略演进的文献综述

随着脱贫攻坚的胜利,农户家庭的生计策略随之改变,以往农户基于贫困脆弱性进行家庭生计策略的选择,但随着农户保障和风险负担机制的不断完善,农户家庭生计策略发生转变且呈现出多样性。文献分析结果表明,相比于贫困脆弱性,发展韧性更关注对风险冲击的抵御能力以及事后恢复能力,从而能够以全面、动态的视角研究农户家庭生计,对促进农户生计可持续性、增强农户自身发展动力具有重要意义。本文将基于国内外已有研究,对发展韧性的定义、分析框架、测量方法以及相关实证研究等进行梳理和总结,以期为学界研究发展韧性以及乡村振兴背景下农户生计模式的选择提供更为翔实的参考。