The copy number and integration site analysis of IGF-1 transgenic goat

RNA-seq and nuclear proteomics provide insights into the lactation regulation mechanism of goat transfected IGF-I and GH recombinant vectors

There exists little available information on the mechanisms of lactation regulation until now. In order to explore the underlying mechanism, we injected IGF-I and GH recombinant vectors into the mammary gland, then RNA-seq analysis and nuclear proteomics were used for rapid high-throughput screening of DEGs and DEPs in the two groups linked to lactation regulation. KEGG analysis of 206 DEGs showed that the same 4 of top 10 enrichment pathways (ECM receptor interaction, protein digestion and absorption, focal adhesion and phagosome) involved in 4 co-expressed genes (IDO, BTG1, ITGB6 and keratin 83), the two groups enriched different metabolic pathways yet. Nuclear proteomics analysis showed 75 and 36 DEPs in the IGF-I and GH group respectively; Sixteen common proteins were identified between the IGF-I group and GH group, four of which (ALB, TPT1, CXXC-5 and ACTR2) significantly decreased and three of which (PRP1, PAG-9 and Hsp70) significantly increased. Similarly, DEPs in the two groups were enriched in same one of top 10 enrichment pathways (PI3K-Akt signaling pathway). Protein-protein interaction networks highlighted the contribution of glycosphingolipid biosynthesis, porphyrin and chlorophyll metabolism and the Jak-STAT signaling pathway to lactation regulation of GH and IGFI. GH and IGF-I improve milk yield, which may be linked to important nodal proteins (ALB and ACTB). Our research advances the understanding of the mammary gland transcriptome and nuclear proteomics during GH and IGF-I overexpression. Individual genes, proteins and pathways in this study point towards potential targets for lactation regulation.

Sheep and Goat Genome Engineering: From Random Transgenesis to the CRISPR Era

Sheep and goats are valuable livestock species that have been raised for their production of meat, milk, fiber, and other by-products. Due to their suitable size, short gestation period, and abundant secretion of milk, sheep and goats have become important model animals in agricultural, pharmaceutical, and biomedical research. Genome engineering has been widely applied to sheep and goat research. Pronuclear injection and somatic cell nuclear transfer represent the two primary procedures for the generation of genetically modified sheep and goats. Further assisted tools have emerged to enhance the efficiency of genetic modification and to simplify the generation of genetically modified founders. These tools include sperm-mediated gene transfer, viral vectors, RNA interference, recombinases, transposons, and endonucleases. Of these tools, the four classes of site-specific endonucleases (meganucleases, ZFNs, TALENs, and CRISPRs) have attracted wide attention due to their DNA double-strand break-inducing role, which enable desired DNA modifications based on the stimulation of native cellular DNA repair mechanisms. Currently, CRISPR systems dominate the field of genome editing. Gene-edited sheep and goats, generated using these tools, provide valuable models for investigations on gene functions, improving animal breeding, producing pharmaceuticals in milk, improving animal disease resistance, recapitulating human diseases, and providing hosts for the growth of human organs. In addition, more promising derivative tools of CRISPR systems have emerged such as base editors which enable the induction of single-base alterations without any requirements for homology-directed repair or DNA donor. These precise editors are helpful for revealing desirable phenotypes and correcting genetic diseases controlled by single bases. This review highlights the advances of genome engineering in sheep and goats over the past four decades with particular emphasis on the application of CRISPR/Cas9 systems.

Transgenic overexpression of human LY6K in mice suppresses mature T cell development in the thymus

Lymphocyte antigen 6 family member K (LY6K) is upregulated in a number of types of cancer and promotes tumor cell proliferation and metastasis. In addition, LY6K is involved in tamoxifen resistance in breast cancer. However, the in vivo molecular mechanism of LY6K has not yet been investigated. In the present study, transgenic mice overexpressing human LY6K (hLY6K) were generated using the pMAMneo vector, and the effect of LY6K upregulation in vivo was investigated. A total of 4 transgenic mice were generated, and the gene copy number was examined using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). RT-qPCR demonstrated that mRNA of hLY6K was overexpressed in the thymus and spleen of the transgenic mice compared with wild-type mice. Flow cytometric analysis demonstrated that the proportions of B and T cells in the spleen were similar in wild-type and transgenic mice; however, the proportion of thymic mature T cells decreased in the transgenic mice, while there was an increase in the proportion of naïve T cells. These findings suggest that the overexpression of LY6K suppresses T cell development, and that LY6K is a potential therapeutic target for cancer.

The transgenic animal platform for biopharmaceutical production

The recombinant production of therapeutic proteins for human diseases is currently the largest source of innovation in the pharmaceutical industry. The market growth has been the driving force on efforts for the development of new therapeutic proteins, in which transgenesis emerges as key component. The use of the transgenic animal platform offers attractive possibilities, residing on the low production costs allied to high productivity and quality of the recombinant proteins. Although many strategies have evolved over the past decades for the generation of transgenic founders, transgenesis in livestock animals generally faces some challenges, mainly due to random transgene integration and control over transgene copy number. But new developments in gene editing with CRISPR/Cas system promises to revolutionize the field for its simplicity and high efficiency. In addition, for the final approval of any given recombinant protein for animal or human use, the production and characterization of bioreactor founders and expression patterns and functionality of the proteins are technical part of the process, which also requires regulatory and administrative decisions, with a large emphasis on biosafety. The approval of two mammary gland-derived recombinant proteins for commercial and clinical use has boosted the interest for more efficient, safer and economic ways to generate transgenic founders to meet the increasing demand for biomedical proteins worldwide.