Recent advances in transgenic technology

Advances in Mechanism and Application of Molecular Breeding of Medicinal Mushrooms: A Review

With the development of molecular biology and genomics technology, mushroom breeding methods have changed from single traditional breeding to molecular breeding. Compared with traditional breeding methods, molecular breeding has the advantages of short time and high efficiency. It breaks through the restrictive factors of conventional breeding and improves the accuracy of breeding. Molecular breeding technology is gradually applied to mushroom breeding. This paper summarizes the concept of molecular breeding and the application progress of various molecular breeding technologies in mushroom breeding, in order to provide reference for future research on mushroom breeding.

A Novel Approach of Transducing Recombinant Baculovirus into Primary Lymphoid Cells of Penaeus monodon for Developing Continuous Cell Line

Cell line development from shrimp is not a novel venture as researchers across the globe have been trying to have crustacean cell lines over 30 years. The reason for not attaining a crustacean or precisely a shrimp cell line is believed to be the replicative senescence and the inability to maintain telomere length in vitro. Moreover, spontaneous in vitro transformations do not happen in shrimp cells. Oncogenic induction in primary cell culture is one of the ways to attain in vitro transformation by way of disrupting the mechanisms which involve cellular senescence. In this context, a recombinant baculovirus with shrimp viral promoter IHHNV-P2 was used for the transduction aimed at immortalization. An oncogene, H-ras, was successfully amplified and cloned in to the baculoviral vector, downstream to shrimp viral promoter IHHNV-P2 and upstream to GFP. Recombinant baculovirus with H-ras was generated and used for transduction into shrimp lymphoid cells during early dividing stage. Accordingly, fibroblast-like primary cell culture got developed, and H-ras and GFP expression could be confirmed. The study suggests that the simple method of incubating recombinant baculovirus with minced tissue enables in vitro transduction during early dividing stage of the cells, and the transduction efficiency gets enhanced by adding 5 mM sodium butyrate to the culture medium.

Transgenesis via permanent integration of genes in repopulating spermatogonial cells in vivo

Current techniques for making transgenic mice are cumbersome, requiring trained personnel, costly infrastructure and collection of many zygotes from mice that are then killed. We developed a reproducible nonterminal technique for transfecting genes in undifferentiated spermatogonia through in vivo electroporation of the testis; about 94% of male mice electroporated with different transgenes successfully sired transgenic pups. Such electroporated males provide a valuable resource for continuous production of transgenic founders for more than a year.

Stable expression of the alkaline phosphatase marker gene by neural cells in culture and after transplantation into the CNS using cells derived from a transgenic rat

Multipotent stem cells and more developmentally restricted precursors have previously been isolated from the developing nervous system and their properties analyzed by culture assays in vitro and by transplantation in vivo. However, the variety of labeling techniques that have been used to identify grafted cells in vivo have been unsatisfactory. In this article we describe the characteristics of cells isolated from a transgenic rat in which the marker gene human placental alkaline phosphatase (hPAP) is linked to the ubiquitously active R26 gene promoter. We show that hPAP is readily detected in embryonic neuroepithelial stem cells, neuronal-restricted precursor cells, and glial-restricted precursor cells. Transgene expression is robust and can be detected by both immunocytochemistry and histochemistry. Furthermore, the levels of hPAP on the cell surface are sufficient for live cell labeling and fluorescence-activated cell sorting. Expression of hPAP is stable in isolated cells in culture and in cells transplanted into the spinal cord for at least 1 month. We submit that cells isolated from this transgenic rat will be valuable for studies of neural development and regeneration.