转基因制品及其安全性问题探讨

概述了转基因生物的历史和现状,介绍了转基因制品存在的安全性问题,分析了转基因制品潜在的风险和危害,提出了对我国转基因制品进行科学管理的方法。     

利用微滴式数字PCR技术检测大豆毛油中的转基因成分

我国是转基因大豆的进口大国,由转基因大豆加工而成的大豆油成为进入消费者生活的食用油,判定食用的大豆油是否含有转基因成分,是国家监管部门和公众消费者密切关心、关注的问题。大豆油在制备精炼过程中破坏了大豆的DNA,造成检验时DNA富集难度增加,严重影响了大豆油转基因成分检测的准确度。到目前为止,国家已经颁布的标准中没有涉及转基因大豆油的检测标准。本研究利用高灵敏度、精确度的数字PCR技术,并通过优化大豆毛油DNA提取方法和PCR反应体系,对大豆毛油样品进行外源转基因成分检测。检测结果显示,大豆毛油外源转基因成分被成功检测到。实验结果表明,本研究建立的大豆毛油转基因成分检测方法准确可靠,可进行推广应用。     

生物工程牛羊肉的质量和安全性研究进展

生物工程动物在畜牧业生产以及生物医学上具有广阔和诱人的应用前景,但是生物工程肉制品的安全性在世界范围内备受关注。综述生物工程技术的应用及生物工程牛羊肉的质量和安全性研究进展,并介绍了生物工程动物的社会化进程。     

Isolation of a pollen specific promoter in tritordeum

The promoter is an important cis-acting element in regulating gene expression. Tissue specific promoters play a key role in genetic engineering. A promoterless plasmid containing UidA gene was transformed into tritordeum by barmbadment. Histochemical analysis of various tissues in transgenic tritordeum was carried to examine tissue-specific expression of GUS activity. The pollen-specific promoter was trapped and identified successfully in a transformant line. PCR method was used to isolate this pollen-specific promoter with DNA extracted from leaves as templates, using primer P1 of rice pollen specific promoter as forward primer, a fragment of UidA gene as the reverse primer P2. By sequencing and analyzing the amplified 1052bp DNA fragment from PCR reaction, a part of UidA gene and a flanking sequence were obtained. Some essential elements of plant promoters were found in the sequence. To determine the function of this promoter, the cloned promoter fragment was fused with uidA gene, then cloned into a plasmid and transformed into Triticum durum. The transgenic plant transformed by this vector showed GUS expression only in pollen. Therefore a pollen-specific promoter was trapped and isolated successfully, and it could be used in gene regulation study and genetic engineering.     

Investigating Immune Responses to the scAAV9-HEXM Gene Therapy Treatment in Tay–Sachs Disease and Sandhoff Disease Mouse Models

GM2 gangliosidosis disorders are a group of neurodegenerative diseases that result from a functional deficiency of the enzyme β-hexosaminidase A (HexA). HexA consists of an α- and β-subunit; a deficiency in either subunit results in Tay–Sachs Disease (TSD) or Sandhoff Disease (SD), respectively. Viral vector gene transfer is viewed as a potential method of treating these diseases. A recently constructed isoenzyme to HexA, called HexM, has the ability to effectively catabolize GM2 gangliosides in vivo. Previous gene transfer studies have revealed that the scAAV9-HEXM treatment can improve survival in the murine SD model. However, it is speculated that this treatment could elicit an immune response to the carrier capsid and “non-self”-expressed transgene. This study was designed to assess the immunocompetence of TSD and SD mice, and test the immune response to the scAAV9-HEXM gene transfer. HexM vector-treated mice developed a significant anti-HexM T cell response and antibody response. This study confirms that TSD and SD mouse models are immunocompetent, and that gene transfer expression can create an immune response in these mice. These mouse models could be utilized for investigating methods of mitigating immune responses to gene transfer-expressed “non-self” proteins, and potentially improve treatment efficacy.     

生物技术食品的安全性及其评价方法

生物技术食品是指利用基因工程技术将外源性基因转移至各种微生物、植物和动物体内,或通过改变现有基因表达等方式所生产的食品。本文简要介绍了生物技术食品安全性评价的实质等效性概念,并就转基因及其产物的内在毒性,新的遗传物质插入宿主基因组所造成的意外影响两大主要问题从理论推测和实验结果评述两个方面对生物技术食品安全性进行全面的分析和探讨。另外叙述并分析了目前的安全性评价方法的现状和挑战。     

Development of a polymerase chain reaction assay for detection of three canola transgenes

Many countries are developing or implementing regulatory requirements to monitor for the presence of genetically modified (GM) materials in seeds, grain, and derived food products using DNA and protein-based methods. There is no published report on the detection of different GM transgenes in canola, and this study is aimed at developing qualitative PCR methods for the three major GM transgenes commercially available in canola. Primer sequences were generated from Gen-Bank and previously published information to develop a polymerase chain reaction (PCR) detection method for Roundup Ready (glyphosate tolerance, GT73 event), Liberty Link (glufosinate ammonium tolerance, HCN92 event), and BX (Bromoxynil tolerance, OXY235 event) canola varieties. On using PCR, two primer pairs for each of the GT73 and HCN92 and one primer pair for OXY235 amplified specific amplicons for the three GM transgenes. All three GM transgenes were detected simultaneously by multiplexing the five primer pairs in a single PCR reaction. Multiplexing of the five primer pairs for DNA prepared at 1% (one GM seed in 99 non-GM seeds) and 0.5% (one GM seed in 199 non-GM seeds) levels generated the expected DNA fragments for GT73, HCN92, and OXY235. This information will lay the groundwork for the development of a quantitative PCR assay for canola transgenic events.     

舟山口岸进境玉米转基因情况分析

转基因农产品安全一直是国家和社会群众高度关注的问题。通过回顾转基因玉米的发展历程,分析国际上主要国家针对转基因农产品的管理情况和相关法律法规,结合舟山口岸近几年转基因玉米检验的工作情况,以及现阶段针对转基因产品监管存在的问题和面临的风险,提出针对性建议以便于检验检疫部门更好地进行转基因玉米的进出口监管工作。     

Recombinant Silk Proteins with Additional Polyalanine Have Excellent Mechanical Properties

This paper explores the structures of exogenous protein molecules that can effectively improve the mechanical properties of silkworm silk. Several transgenic vectors fused with the silkworm fibroin light chain and type 3 repeats in different multiples of the ampullate dragline silk protein 1 (MaSp1) from black widow spider with different lengths of the polyalanine motifs were constructed for this study. Transgenic silkworms were successfully obtained by piggyBac-mediated microinjection. Molecular detection showed that foreign proteins were successfully secreted and contained within the cocoon shells. According to the prediction of PONDR^® VSL2 and PONDR^® VL-XT, the type 3 repeats and the polyalanine motif of the MaSp1 protein were amorphous. The results of FTIR analysis showed that the content of β-sheets in the silk of transgenic silkworms engineered with transgenic vectors with additional polyalanine was significantly higher than that of wild-type silkworm silk. Additionally, silk with a higher β-sheet content had better fracture strength and Young’s modulus. The mechanical properties of silk with longer chains of exogenous proteins were improved. In general, our results provide theoretical guidance and technical support for the large-scale production of excellent bionic silk.