Reproductive characteristics of transgenic (TG) chickens caping an exogenous gene

An exogenous gene (lacZ/MiwZ) introduced into the germinal crescent region (GCR) of avian embryos was con-firmed to be successfully transferred to the gonads via the primordial germ cells (PGCs). Following hatching, the chickswere raised until the stage of sexual maturation. The incorporation of MiwZ DNA was detected in male and female trans-genic chickens, respectively. The normal male and female transgenic birds were subjected to artificial insemination ac-cording to routine methods. Fertilized eggs obtained from female transgenic chickens were incubated for 72 h and the em-bryos removed from the yolk were examined by X-gal staining to detect the introduction of MiwZ in the offspring. As aresult, the expression of MiwZ was detected in the offspring. Furthermore, the presence of MiwZ in the extracts fromembryos was also detected by polymerase chain reaction (PCR) analysis. In male transgenic chickens, the presence of in-jected MiwZ in the extracts from sperm was also confirmed. The exogenous gene introduced into the GCR migrated suc-cessfully to the gonad resulting in its incorporation into the offspring and spermatozoa of transgenic chickens. (Asian JAndrol 1999 Sep ; 1: 139 - 144)

Exogenous reference gene normalization for real-time reverse transcription-polymerase chain reaction analysis under dynamic endogenous transcription

Quantitative real-time reverse transcription-polymerase chain reaction （qPCR） is widely used to investigate transcriptional changes following experimental manipulations to the nervous system. Despite the widespread utilization of qPCR, the interpretation of results is marred by the lack of a suitable reference gene due to the dynamic nature of endogenous transcription. To address this inherent deficiency, we investigated the use of an exogenous spike-in mRNA, luciferase, as an internal reference gene for the 2ct normalization method. To induce dynamic transcription, we systemically administered capsaicin, a neurotoxJn selective for C-type sensory neurons expressing the TRPV-1 receptor, to adult male Sprague-Dawley rats. We later isolated nodose ganglia for qPCR analysis with the reference being either exogenous luciferase mRNA or the commonly used endogenous reference 13-111 tubulin. The exogenous luciferase mRNA reference clearly demonstrated the dynamic expression of the endogenous reference. Furthermore, variability of the endogenous reference would lead to misinterpretation of other genes of interest. In conclusion, traditional reference genes are often unstable under physiologically normal situations, and certainly unstable following the damage to the nervous system. The use of exogenous spike-in reference provides a consistent and easily implemented alternative for the analysis of qPCR data.

The establishment of stable transfection of human breast cancer cell line MDA-MD-468 with exogenous PTEN gene

To investigate exogenous PTEN gene transfected human breast cancer cell line MDA-MD-468.Methods Using the lipofectamine 2000 transfection technique,wild type PTEN gene was transducted into an in vitro cultured highly metastatic breast cancer cell line MDA-MD-468.After transfection,the cells were selected by G418.The resistant clones were chosen and expanded in DMEM culture medium.RT-PCR,immunohistochemical method and western blot were used to determine the expression of target genes.Results An anti-G418 cell clone was established and expanded in culture.The transfected PTEN gene MDA-MD-468 cells showed expression of PTEN mRNA and PTEN protein.Conclusion Human breast cancer cell line MDA-MB-468 established in this study expresses consistently exogenous PTEN genes.4 refs,6 figs.

Biological effect of expression of exogenous human nuclear receptor hLRH-1 in SW480 cells and its molecular mechanism

Objective： To explore the possible biological function of human nuclear receptor hLRH-1 in tumorigenesis and progress of colon cancer. Methods： Plasmids pcDNA3-hLRH-1 were introduced into SW480 cells via lipofectamine. The expression of mRNA and protein of exogenous hLRH-1 were detected by RT-PCR and western blotting, respectively. MTT assay was carried out to survey the proliferation of SW480 cells with overexpression of hLRH-1. Meanwhile, the expression of proliferation-related genes cyclin E1 and cyclin D1, and apoptosis-related genes PTEN and Rbl, were analyzed by realtime RT-PCR. Results： The proliferation of SW480 cells was promoted under the condition of overexpression of hLRH-1. The expression of cyclin E1 was up-regulated significantly, while that of PTEN and Rbl were down-regulated in SW480 cells with overexpressed hLRH-1. Conclusion： The expression of exogenous hLRH-1 in SW480 cells induced the proliferation resulting form up-regulation of cyclin E1, as well as participated in the regulation of apoptosis via influencing the expression of PTEN and Rb1.

EXPRESSION OF rhBMP-7 GENE IN TRANSDUCED BONE MARROW DERIVED STROMAL CELLS

OBJECTIVE: To explore the possibility of expression of exogenous gene in transduced bone marrow derived stromal cells (BMSCs). METHODS: The marker gene, pbLacZ, was transferred into cultured BMSCs and the expression of transduced gene by X-gal staining was examined. Then plasmid pcDNA3-rhBMP7 was delivered to cultured BMSCs. Through immunohistochemical staining and RT-PCR assay, the expression of rhBMP7 gene was detected. RESULTS: The exogenous gene could be expressed efficiently in transduced BMSCs. CONCLUSION: The present study provided a theoretical basis to gene therapy on the problems of bone and cartilage tissue.

Alphaherpesvirus-vectored vaccines against animal diseases: Current progress

Recombinant virus-vectored vaccines are novel agents that can effectively activate specific and nonspecific immunity,are multivalent and multieffective,and have high safety ratings.Animal alphaherpesviruses have a large genome,contain multiple nonessential regions that do not affect viral replication and are capable of accepting the insertion of an exogenous gene and expressing the antigen protein.Furthermore,animal alphaherpesviruses have a wide host spectrum,can replicate in the host and continuously stimulate the animal to produce immunity to the corresponding pathogen,thus making them ideal carriers for recombinant virus-vectored vaccines.With the development of gene-editing technology,recombinant viruses capable of expressing foreign genes can be constructed by various methods.Currently,studies on recombinant virusvectored vaccines constructed based on animal alphaherpesviruses have involved poultry,pigs,cattle,sheep,and companion animals.Studies have shown that the construction of recombinant animal alphaherpesviruses enables the acquisition of immunity to multiple diseases.This article mainly summarizes the current progress on animal alphaherpesvirus-vectored vaccines,aiming to provide reference for the development of new animal alphaherpesvirus-vectored vaccines.

Characteristics of Pollen from Transgenic Lines of Apple Carrying the Exogenous CpTI Gene

It is fundamental for gene transformation and ecosystem hazard evaluation to study the pollen characteristics of transgenic plants. In this research,the characteristics of pollen from 7-or 8-year-old transgenic apple plants carrying an exogenous Cp TI gene were analyzed. The results showed that there was no significant difference in terms of size,morphology,or exine ornamentation between the pollen of the transgenic plants and the non-transgenic control. However,the transgenic plants had more abnormal pollen grains. Of the 13 transgenic lines tested,12 had a significantly lower amount of pollen and six exhibited a significantly lower germination rate when cultured in vitro. The pollen viability of three transgenic lines was determined,with two showing significantly lower viability than the control. The transgenic Gala apple pollen grains germinated normally via controlled pollination on Fuji apple stigmas. However,the pollen tubes extended relatively slowly during the middle and late development stages,and another 8 h were needed to reach the ovules compared with the control. The gibberellic acid concentration in transgenic Gala apple flowers was lower than in the non-transgenic control during all development stages tested. The abscisic acid concentration in the transgenic flowers was lower during the pink stage,and higher during the ball and fully open stages. Microscopic observation of the anther structure showed no difference. The tapetum of the pollen sac wall in transgenic plants decomposed late and affected pollen grain development,which could be one of the reasons for the lower number of pollen grains and poor viability in the transgenic plants.

Advances in Transgenic Breeding of Anthurium andraeanum

At present, transgenic technologies have become important means of plant breeding, and the application and promotion of transgenic technologies have created huge economic and social benefits. Transgenic plant products have significantly affected human life. Anthurium andraeanum is the second major tropical potted flower and its transgenic breeding has a promising prospect of application. In this paper, acceptors, transformation methods and introduced exogenous genes （ including reporter genes, selectable marker genes and target genes） of Anthurium andraeanum were summarized; in addition, several issues related to transforma- tion of Anthurium andraeanum were analyzed, aiming at providing reference for transgenic breeding of Anthurium andraeanum.

A Viral Expression Vector from Foxtail mosaic virus to Express Green Fluorescent Protein

[Objective]Foxtail mosaic virus(FoMV)infects gramineous and dicotyledonous plants.In this study,we sought to construct a viral vector based on FoMV to express exogenous proteins in plants.[Method]A recombinant viral expression vector was constructed by inserting the promotor of Potato virus X(PVX)and exogenous gene sequences into the 3’non-coding region of the FoMV coat protein gene.[Results]The plasmid pCB301-FoMV-CP-PVXprom-GFP expressed green fluorescent protein in inoculated Nicotiana benthamiana leaves.[Conclusion]A recombinant viral expression vector was constructed successfully.

Efficient and genotype independent maize transformation using pollen transfected by DNA-coated magnetic nanoparticles

Current gene delivery methods for maize are limited to specific genotypes and depend on timeconsuming and labor-intensive tissue culture techniques.Here,we report a new method to transfect maize that is culture-free and genotype independent.To enhance efficiency of DNA entry and maintain high pollen viability of 32%-55%,transfection was performed at cool temperature using pollen pretreated to open the germination aperture(40%–55%).Magnetic nanoparticles(MNPs)coated with DNA encoding either red fluorescent protein(RFP),β-glucuronidase gene(GUS),enhanced green fluorescent protein(EGFP)or bialaphos resistance(bar)was delivered into pollen grains,and female florets of maize inbred lines were pollinated.Red fluorescence was detected in 22%transfected pollen grains,and GUS stained 55%embryos at 18 d after pollination.Green fluorescence was detected in both silk filaments and immature kernels.The T1 generation of six inbred lines showed considerable EGFP or GUS transcripts(29%–74%)quantitated by polymerase chain reaction,and 5%–16%of the T1 seedlings showed immunologically active EGFP or GUS protein.Moreover,1.41%of the bar transfected T1 plants were glufosinate resistant,and heritable bar gene was integrated into the maize genome effectively as verified by DNA hybridization.These results demonstrate that exogenous DNA could be delivered efficiently into elite maize inbred lines recalcitrant to tissue culture-mediated transformation and expressed normally through our genotype-independent pollen transfection system.