Molecular-based environmental risk assessment of three varieties of genetically engineered cows

A review of transgenic animal techniques and their applications

Nowadays, breakthroughs in molecular biology are happening at an unprecedented rate. One of them is the ability to engineer transgenic animals. A transgenic animal is one whose genome has been changed to carry genes from another species or to use techniques for animal genome editing for specific traits. Animal features can be changed by purposefully altering the gene (or genes). A mouse was the first successful transgenic animal. Then pigs, sheep, cattle, and rabbits came a few years later. The foreign-interested genes that will be used in animal transgenic techniques are prepared using a variety of methods. The produced gene of interest is placed into a variety of vectors, including yeast artificial chromosomes, bacterial plasmids, and cosmids. Several techniques, including heat shock, electroporation, viruses, the gene gun, microinjection, and liposomes, are used to deliver the created vector, which includes the interesting gene, into the host cell. Transgenesis can be carried out in the gonads, sperm, fertilized eggs, and embryos through DNA microinjection, retroviruses, stem cells, and cloning. The most effective transgenic marker at the moment is fluorescent protein. Although transgenesis raises a number of ethical concerns, this review concentrates on the fundamentals of animal transgenesis and its usage in industry, medicine, and agriculture. Transgenesis success is confirmed by the integration of an antibiotic resistance gene, western and southern blots, PCR, and ELISA. If technology solves social and ethical problems, it will be the most promising in the future.

An Event-Specific Real-Time PCR Method for Measuring Transgenic Lysozyme Goat Content in Trace Samples

Lysozymes are used in sterilisation, antisepsis, dairy additives, inflammation, and cancer. One transgenic goat line expressing high levels of human lysozyme (hLZ) in goat milk has been developed in China. Herein, we established an event-specific real-time polymerase chain reaction (real-time PCR) method to detect the transgenic hLZ goat line. The developed method has high specificity, sensitivity and accuracy, and a wide quantitative dynamic range. The limit of detection and limit of quantification was 5 and 10 copies per reaction, respectively. The practical sample analysis results showed that the method could identify and quantify transgenic lysozyme content in trace samples in routine lab analyses. Furthermore, the potential applicability in risk assessment, such as molecular characterisation and gene horizontal transfer, was confirmed. We believe that this method is suitable for the detection of transgenic hLZ goat line and its derivate.

Going wild for functional genomics: RNA interference as a tool to study gene-behavior associations in diverse species and ecological contexts

Identifying the genetic basis of behavior has remained a challenge for biologists. A major obstacle to this goal is the difficulty of examining gene function in an ecologically relevant context. New tools such as CRISPR/Cas9, which alter the germline of an organism, have taken center stage in functional genomics in non-model organisms. However, germline modifications of this nature cannot be ethically implemented in the wild as a part of field experiments. This impediment is more than technical. Gene function is intimately tied to the environment in which the gene is expressed, especially for behavior. Most lab-based studies fail to recapitulate an organism's ecological niche, thus most published functional genomics studies of gene-behavior relationships may provide an incomplete or even inaccurate assessment of gene function. In this review, we highlight RNA interference as an especially effective experimental method to deepen our understanding of the interplay between genes, behavior, and the environment. We highlight the utility of RNAi for researchers investigating behavioral genetics, noting unique attributes of RNAi including transience of effect and the feasibility of releasing treated animals into the wild, that make it especially useful for studying the function of behavior-related genes. Furthermore, we provide guidelines for planning and executing an RNAi experiment to study behavior, including challenges to consider. We urge behavioral ecologists and functional genomicists to adopt a more fully integrated approach which we call "ethological genomics". We advocate this approach, utilizing tools such as RNAi, to study gene-behavior relationships in their natural context, arguing that such studies can provide a deeper understanding of how genes can influence behavior, as well as ecological aspects beyond the organism that houses them.

Research and development on lactoferrin and its derivatives in China from 2011–2015

Lactoferrin (Lf), a multifunctional glycoprotein, is an important antimicrobial and immune regulatory protein present in neutrophils and most exocrine secretions of mammals. Lactoferricin (Lfcin) is located in the N-terminal region of this protein. In this review, the current state of research into Lf and Lfcin in China is described. Searching with HistCite software in Web Sci located 118 papers published by Chinese researchers from 2011–2015, making China one of the top 3 producers of Lf research and development in the world. The biological functions of Lf and Lfcin are discussed, including antibacterial, antiviral, antifungal, anticarcinogenic, and anti-inflammatory activities; targeted drug delivery, induction of neurocyte, osteoblast, and tenocyte growth, and possible mechanisms of action. The preparation and heterologous expression of Lf in animals, bacteria, and yeast are discussed in detail. Five Lf-related food additive factories and 9 Lf-related health food production companies are certified by the China Food and Drug Administration (CFDA). The latest progress in the generation of transgenic livestock in China, the safety of the use of transgenic animals, and future prospects for the uses of Lf and Lfcin are also covered.

Fungal pretreatment of raw digested piggery wastewater enhancing the survival of algae as biofuel feedstock

BACKGROUND

Understanding about the impact of white rot fungi on indigenous bacterial communities, NH₄⁺ and turbidity in digested piggery wastewater, will allow the optimization of wastewater treatment methods and its use as a feasible medium for algal growth. Here, the white rot fungi were inoculated into undiluted and unsterilized digested piggery wastewater under different temperatures and pH regimes in order to lower the pretreatment cost. Diversity and abundance of the bacterial communities in the pretreated wastewater were assessed by PCR-denaturing gradient gel electrophoresis coupled with 16S rDNA sequencing.

RESULTS

The research showed a significant reduction on the microbial diversity with the presence of white rot fungi which occur at pH 6. The distribution and presence of bacteria taxa were strongly correlated with NH₄⁺ concentration, pH, and the presence of white rot fungi. Variance partition analysis also showed that the effect on the chlorophyll content of algae in fungi-filtered wastewater was as the following hierarchy: bacterial diversity > NH₄⁺ > turbidity. Therefore, the algae in treated wastewater with less abundance of bacteria proliferated more successfully, indicating that bacterial community not only played an important role in algal growth but also imposed a strong top-down control on the algal population. The algae grown in wastewater treated with fungi reached the highest specific growth rate (0.033 day^-1), whereas the controls displayed the negative specific growth rate. The fatty acid composition varied markedly in C16:0 and C18:0 between these treatments, with a higher content of C16:0.

CONCLUSIONS

This study firstly showed that Chlorella can grow as cost-effective biofuel feedstocks in undiluted and unsterilized digested wastewater with high ammonium concentration and dark brown color because the bacterial abundance of digested piggery wastewater could be reduced greatly by the white rot fungi.

Effects of Genetically Modified Milk Containing Human Beta-Defensin-3 on Gastrointestinal Health of Mice

This study was performed to investigate the effects of genetically modified (GM) milk containing human beta-defensin-3 (HBD3) on mice by a 90-day feeding study. The examined parameters included the digestibility of GM milk, general physical examination, gastric emptying function, intestinal permeability, intestinal microflora composition of mice, and the possibility of horizontal gene transfer (HGT). The emphasis was placed on the effects on gastrointestinal (GI) tract due to the fact that GI tract was the first site contacting with food and played crucial roles in metabolic reactions, nutrition absorption and immunity regulation in the host. However, the traditional methods for analyzing the potential toxicological risk of GM product pay little attention on GI health. In this study, the results showed GM milk was easy to be digested in simulated gastric fluid, and it did not have adverse effects on general and GI health compared to conventional milk. And there is little possibility of HGT. This study may enrich the safety assessment of GM product on GI health.

Impacts of human lysozyme transgene on the microflora of pig feces and the surrounding soil

The rapid development of genetic engineering and extensive applications of genetically engineered (GE) animals have provided many research benefits, but concerns have been raised over the potential environmental impact of transgenic animals. We investigated the effects of human lysozyme (hLZ) transgenic pigs which can express hLZ in their mammary glands on the surrounding environment from the angle of the changes of pig feces and the surrounding soil, including the probability of horizontal gene transfer (HGT), the impact on microbial communities in pig gastrointestinal (GI) tracts and soil, and the influence on the total nitrogen (TN) and total phosphorus (TP) content of pig excrement and surrounding soil. Results showed that hLZ gene was not detected by polymerase chain reaction (PCR) or quantitative real-time PCR (Q-PCR) in gut microbial DNA extracts of manure or microbial DNA extracts of topsoil. PCR-Denaturing Gradient Gel Electrophoresis (PCR-DGGE) analysis and 16S rDNA sequence analysis showed that hLZ gene had no impact on the microflora structure of pig guts or soil. Finally, TN and TP contents were not significantly different in pig manure or soils taken at different distances from the pig site (P>0.25).

Transgenic milk containing recombinant human lactoferrin modulates the intestinal flora in piglets1This article is part of a Special Issue entitled Lactoferrin and has undergone the Journal’s usual peer review process

Lactoferrin (LF) is a beneficial multifunctional protein in milk. The objective of this study was to determine whether bovine transgenic milk containing recombinant human lactoferrin (rhLF) can modulate intestinal flora in the neonatal pig as an animal model for the human infant. We fed 7-day-old piglets (i) ordinary whole milk (OM), (ii) a 1:1 mixture of OM and rhLF milk (MM), or (iii) rhLF milk (LFM). LFM provided better average daily mass gain than OM (P = 0.007). PCR–denaturing gradient gel electrophoresis and 16S rDNA sequencing analysis revealed that the LFM piglets exhibited more diversity of the intestinal flora than the OM group. Except for the colon in the LFM group, an increasing trend in microbial diversity occurred from the duodenum to the colon. Fecal flora was not different across different ages or different treatment groups, but a cluster analysis showed that the fecal flora of OM- and MM-fed piglets had a higher degree of similarity than that of LFM-fed piglets. Based on culture-based bacterial counts of intestinal content samples, concentrations of Salmonella spp. in the colon and of Escherichia coli throughout the intestine were reduced with LFM (P < 0.01). Concentrations of Bifidobacterium spp. in the ileum and of Lactobacillus spp. throughout the intestine were also increased with LFM (P ≤ 0.01). We suggest that rhLF can modulate the intestinal flora in piglets.