African swine fever virus (ASFV) causes a lethal, haemorrhagic disease in domestic swine that threatens pig production across the globe. Unlike domestic pigs, warthogs, which are wildlife hosts of ...the virus, do not succumb to the lethal effects of infection. There are three amino acid differences between the sequence of the warthog and domestic pig RELA protein; a subunit of the NF-κB transcription factor that plays a key role in regulating the immune response to infections. Domestic pigs with all 3 or 2 of the amino acids from the warthog RELA orthologue have been generated by gene editing. To assess if these variations confer resilience to ASF we established an intranasal challenge model with a moderately virulent ASFV. No difference in clinical, virological or pathological parameters were observed in domestic pigs with the 2 amino acid substitution. Domestic pigs with all 3 amino acids found in warthog RELA were not resilient to ASF but a delay in onset of clinical signs and less viral DNA in blood samples and nasal secretions was observed in some animals. Inclusion of these and additional warthog genetic traits into domestic pigs may be one way to assist in combating the devastating impact of ASFV.
Although there is a range of systems available for production of therapeutic proteins, there are valid reasons for developing transgenic chickens as an additional method that has specific advantages.
...The potential of using transgenic animals for the synthesis of therapeutic proteins was suggested over twenty years ago. Considerable progress has been made in developing methods for the production of transgenic animals and specifically in the expression of therapeutic proteins in the mammary glands of cows, sheep and goats. Development of transgenic hens for protein production in eggs has lagged behind these systems. The positive features associated with the use of the chicken in terms of cost, speed of development of a production flock and potentially appropriate glycosylation of target proteins have led to significant advances in transgenic chicken models in the past few years.
Scientists have long sought a technology to humanely control populations of damaging invasive pests in a species-specific manner. Gene drive technology could see this become a reality. This review ...charts the twists and turns on the road to developing gene drives in vertebrates. We focus on rodents, as these will likely be the first targets, and trace the journey from the early understanding of selfish genetic elements to engineering gene drives in mice; before discussing future research focuses and the crucial role that public perception and governance will play in the application of this technology. The realisation of robust gene drive strategies in vertebrate pests has the potential to revolutionise biocontrol.
The global demand for animal-based food products is anticipated to increase by 70% by 2050. Meeting this demand in a way that has minimal impact on the environment will require the implementation of ...advanced technologies. Genome editing of livestock is a tool that will allow breeders to improve animal welfare, performance and efficiency, paving the way to a more sustainable future for livestock agriculture. Currently, genome editing of livestock is limited to specialized laboratories due to the complexity of techniques available for the delivery of genome editing reagents into zygotes and reproductive cells. The emergence of three cutting-edge reproductive technologies—(i) zygote electroporation, (ii) zygote transduction of recombinant adeno-associated virus (rAAV), and (iii) surrogate sire technology—will provide livestock breeders with a new toolkit of delivery strategies for genome editing. The simplicity of these technologies will enable widespread on-farm application in major livestock species by seamlessly integrating into current breeding systems. We believe it is timely to highlight these three cutting-edge reproductive technologies for genome editing and have outlined pipelines for their implementation in on-farm settings. With a nuanced regulatory framework these technologies could fast-track livestock genetic gain and help secure a sustainable future for livestock.
The impact of neurological disorders is recognised globally, with one in six people affected in their lifetime and few treatments to slow or halt disease progression. This is due in part to the ...increasing ageing population, and is confounded by the high failure rate of translation from rodent-derived therapeutics to clinically effective human neurological interventions. Improved translation is demonstrated using higher order mammals with more complex/comparable neuroanatomy. These animals effectually span this translational disparity and increase confidence in factors including routes of administration/dosing and ability to scale, such that potential therapeutics will have successful outcomes when moving to patients. Coupled with advancements in genetic engineering to produce genetically tailored models, livestock are increasingly being used to bridge this translational gap.
In order to aid in standardising characterisation of such models, we provide comprehensive neurological assessment protocols designed to inform on neuroanatomical dysfunction and/or lesion(s) for large animal species. We also describe the applicability of these exams in different large animals to help provide a better understanding of the practicalities of cross species neurological disease modelling.
We would encourage the use of these assessments as a reference framework to help standardise neurological clinical scoring of large animal models.
•Direct comparing two surrogate reporter systems for enriching genome edited cells.•RGS reporter was proved to be more effective than the SSA reporter.•Both reporter systems enrich Cas9 induced ...mutations more effective than ZFNs.•RGS reporter can select Cas9 induced mutations at frequencies as high as 70%.
Genome editors are powerful tools that allow modification of the nuclear DNA in eukaryotic cells both in vitro and in vivo. In vitro modified cells are often phenotypically indistinguishable from unmodified cells, hampering their isolation for analysis. Episomal reporters encoding fluorescent proteins can be used for enrichment of modified cells by flow cytometry. Here we compare two surrogate reporters, RGS and SSA, for the enrichment of porcine embryonic fibroblasts containing mutations induced by ZFNs or CRISPR/Cas9. Both systems were effective for enrichment of edited porcine cells with the RGS reporter proving more effective than the SSA reporter. We noted a higher-fold enrichment when editing events were induced by Cas9 compared to those induced by ZFNs, allowing selection at frequencies as high as 70%.
The major physiological function of milk is the transport of amino acids, carbohydrates, lipids and minerals to mammalian offspring. Caseins, the major milk proteins, are secreted in the form of a ...micelle consisting of protein and calcium-phosphate.We have analysed the role of the milk protein α-casein by inactivating the corresponding gene in mice. Absence of α-casein protein significantly curtails secretion of other milk proteins and calcium-phosphate, suggesting a role for α-casein in the establishment of casein micelles. In contrast, secretion of albumin, which is not synthesized in the mammary epithelium, into milk is not reduced. The absence of α-casein also significantly inhibits transcription of the other casein genes. α-Casein deficiency severely delays pup growth during lactation and results in a life-long body size reduction compared to control animals, but has only transient effects on physical and behavioural development of the pups. The data support a critical role for α-casein in casein micelle assembly. The results also confirm lactation as a critical window of metabolic programming and suggest milk protein concentration as a decisive factor in determining adult body weight.
Pluripotential stem cells from livestock offer an exciting prospect for the biotechnology industry. Applying strategies established for the derivation of murine induced pluripotential stem cells ...(iPSCs), we have isolated ovine iPSCs that can give rise to cells characteristic of all three germ cell layers both in vitro from embryoid bodies and in teratomas in vivo. Furthermore, although at a low level, these ovine iPS cells can contribute to live-born chimeric lambs. Colonies derived from ovine embryonic fibroblasts transfected with murine cMyc, Klf4, Oct4, and Sox2 displayed smooth domes with sharp edges when grown in human embryonic stem cell (ESC) medium but not in mouse ESC medium. These ovine iPSCs were alkaline phosphatase positive, expressed Nanog, and had a normal karyotype. These cells represent an important step in the understanding of mechanistic nature of pluripotency in ungulates.
Genetically engineering milk Whitelaw, C. Bruce A.; Joshi, Akshay; Kumar, Satish ...
Journal of dairy research,
02/2016, Letnik:
83, Številka:
1
Journal Article
Recenzirano
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It has been thirty years since the first genetically engineered animal with altered milk composition was reported. During the intervening years, the world population has increased from 5bn to 7bn ...people. An increasing demand for protein in the human diet has followed this population expansion, putting huge stress on the food supply chain. Many solutions to the grand challenge of food security for all have been proposed and are currently under investigation and study. Amongst these, genetics still has an important role to play, aiming to continually enable the selection of livestock with enhanced traits. Part of the geneticist's tool box is the technology of genetic engineering. In this Invited Review, we indicate that this technology has come a long way, we focus on the genetic engineering of dairy animals and we argue that the new strategies for precision breeding demand proper evaluation as to how they could contribute to the essential increases in agricultural productivity our society must achieve.
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