title: Molecular-based environmental risk assessment of three varieties of genetically engineered cows.
abstract: The development of animal biotechnology has led to an increase in attention to biosafety issues. Here we evaluated the impact of genetically engineered cows on the environment. The probability of horizontal gene transfer and the impact on the microbial communities in cow gut and soil were tested using three varieties of genetically engineered cows that were previously transformed with a human gene encoding lysozyme, lactoferrin, or human alpha lactalbumin. The results showed that the transgenes were not detectable by polymerase chain reaction (PCR) or quantitative real-time PCR in gut microbial DNA extracts of manure or microbial DNA extracts of topsoil. In addition, the transgenes had no impact on the microbial communities in cow gut or soil as assessed by PCR-denaturing gradient gel electrophoresis or 16S rDNA sequencing. Furthermore, phylogenetic analyses showed that the manure bacteria sampled during each of the four seasons belonged primarily to two groups, Firmicutes and Bacteroidetes, and the soil bacteria belonged to four groups, Firmicutes, Bacteroidetes, Actinobacteria, and α-proteobacteria. Other groups, such as β-proteobacteria, γ-proteobacteria, δ-proteobacteria, ε-proteobacteria, Spirochaetes, Acidobacteria, Chloroflexi, and Nitrospira, were not dominant in the manure or soil.
authors.affiliation: State Key Laboratory of Agrobiotechnology, China Agricultural University, 100193 Beijing, China.
authors.forename: Jianxiang
authors.initials: J
authors.lastname: Xu
authors.forename: Jie
authors.initials: J
authors.lastname: Zhao
authors.forename: Jianwu
authors.initials: J
authors.lastname: Wang
authors.forename: Yaofeng
authors.initials: Y
authors.lastname: Zhao
authors.forename: Lei
authors.initials: L
authors.lastname: Zhang
authors.forename: Mingxing
authors.initials: M
authors.lastname: Chu
authors.forename: Ning
authors.initials: N
authors.lastname: Li
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified / Q000235:genetics / Q000382:microbiology / Q000502:physiology*; D001483:Base Sequence; D002417:Cattle / Q000235:genetics / Q000382:microbiology / Q000502:physiology*; D055669:Ecological and Environmental Phenomena; D022761:Gene Transfer, Horizontal; D006801:Humans; D007768:Lactalbumin / Q000235:genetics / Q000378:metabolism; D007781:Lactoferrin / Q000235:genetics / Q000378:metabolism; D008372:Manure / Q000382:microbiology; D008969:Molecular Sequence Data; D009113:Muramidase / Q000235:genetics / Q000378:metabolism; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics*; D018570:Risk Assessment; D012988:Soil Microbiology; D019076:Transgenes / Q000235:genetics
chemical_list: D008372:Manure; D012336:RNA, Ribosomal, 16S; D007768:Lactalbumin; D009113:Muramidase; D007781:Lactoferrin