To rapidly and accurately manipulate genome such as gene deletion, insertion and site mutation, the whole genome of a very virulent strain Md5 of Marek's disease virus (MDV) was inserted into bacterial artificial chromosome (BAC) through homogeneous recombination. The recombinant DNA was electroporated into DH10B competent cells and identified by PCR and restriction fragment length polymorphism analysis. An infectious clone of Md5BAC was obtained following transfection into chicken embryo fibroblast (CEF) cells. Furthermore, a lorf10 deletion mutant was constructed by two step Red-mediated homologous recombination. To confirm the specific role of gene deletion, the lorf10 was reinserted into the original site of MDV genome to make a revertant strain. All the constructs were rescued by transfection into CEF cells, respectively. The successful packaging of recombinant viruses was confirmed by indirect immunofluorescence assay. The results of growth kinetics assay and plaques area measurement showed that the lorf10 is dispensable for MDV propagation in vitro. Overall, this study successfully constructed an infectious BAC clone of MDV and demonstrated its application in genome manipulation; the knowledge gained from our study could be further applied to other hepesviruses.
Animals ; Chick Embryo ; Chickens ; Chromosomes, Artificial, Bacterial ; DNA, Recombinant ; Herpesvirus 2, Gallid/genetics* ; Marek Disease

OBJECTIVETo assess the value of combined chromosomal karyotyping and BACs-on-Beads(BoBs) assay for the prenatal diagnosis of high risk gravida from Ningbo.

METHODSFor 2779 women, results of conventional karyotyping analysis and BoBs assay were compared.

RESULTSFor common aneuploidies involving chromosomes 13, 18, 21, X and Y, the two methods have yielded a concordance rate of 98.78%. Eight cases detected with microduplication by BoBs were missed by karyotyping analysis. On the other hand, 17 structural chromosomal abnormalities, 10 chimeras and 1 triploidy detected by karyotyping analysis were missed by BoBs.

CONCLUSIONThe BoBs technology has featured high throughput and rapidity, and can detect 9 microdeletion syndromes, which can improve the quality of prenatal diagnosis and provide an ideal complementary for conventional chromosomal karyotyping.

Adult ; Chromosome Aberrations ; Chromosome Deletion ; Chromosomes, Artificial, Bacterial ; genetics ; Female ; Humans ; Karyotyping ; methods ; Pregnancy ; Prenatal Diagnosis ; methods

OBJECTIVETo determine the origin of a supernumerary small marker chromosome found in a fetus using prenatal BACs-on-Beads (BoBs) and single nucleotide polymorphism array (SNP-array) assays.

METHODSThe fetal sample was subjected to chromosomal karyotyping and BoBs analysis, and the results were validated with genome-wide scanning using a SNP microarray.

RESULTSThe fetus was found to have a 47,XX,+mar karyotype. BoBs analysis indicated that there was an amplification between 18p11.32 and 18p11.21, which was verified by the SNP-array assay as a 18.3 Mb duplication occurring at 18p11.32q11.1.

CONCLUSIONThe karyotype of the fetus was determined as 47,XX,+der18(18p11.32?18q11.1::18q11.1?18p11.32). The duplication has involved important genes including SMCHD1, LPIN2 and TGIF1, which may result in severe malformations in the fetus.

Adult ; Aneuploidy ; Chromosomes, Artificial, Bacterial ; genetics ; Chromosomes, Human, Pair 18 ; genetics ; Female ; Humans ; Karyotyping ; Microarray Analysis ; methods ; Polymorphism, Single Nucleotide ; Pregnancy ; Prenatal Diagnosis ; methods

OBJECTIVETo establish a strategy for screening and diagnosing common microdeletion and microduplication syndromes among children with idiopathic mental retardation and development abnormalities.

METHODSPotential chromosomal variations among patients with unexplained mental retardation, cardiac anomalies, particular facial features, learning disabilities and other clinical characteristics were detected with bacterial artificial chromosome BACs-on-Beads (BoBs) technique and karyotyping. Positive results were verified with array-based comparative genomic hybridization (Array-CGH).

RESULTSFifty eight of the 60 patients had a normal chromosome karyotype. Ten patients with microdeletion and microduplication syndromes were detected by BoBs, which included two positive cases identified through chromosome karyotyping. Two patients were respectively diagnosed as Smith-Magenis syndrome and Prader-Willi/Angelman syndrome by BoBs and the results were confirmed by Array-CGH.

CONCLUSIONBoBs is capable of detecting chromosome microdeletion and microduplication with high specificity and throughput, which can compensate the shortcomings of conventional cytogenetic technology and will be widely applied for clinical diagnosis.

Adolescent ; Child ; Child, Preschool ; Chromosome Deletion ; Chromosome Duplication ; Chromosomes, Artificial, Bacterial ; genetics ; Comparative Genomic Hybridization ; Cytogenetic Analysis ; methods ; Female ; Humans ; Infant ; Infant, Newborn ; Karyotyping ; Male ; Oligonucleotide Array Sequence Analysis

The Cashmere goat is mainly used to produce cashmere, which is very popular for its delicate fiber, luscious softness and natural excellent warm property. Keratin associated protein (KAP) and bone morphogenetic protein (BMP) of the Cashmere goat play an important role in the proliferation and development of cashmere fiber follicle cells. Bacterial artificial chromosome containing kap6.3, kap8.1 and bmp4 genes were used to increase the production and quality of Cashmere. First, we constructed bacterial artificial chromosomes by homology recombination. Then Tol2 transposon was inserted into bacterial artificial chromosomes that were then transfected into Cashmere goat fibroblasts by Amaxa Nucleofector technology according to the manufacture's instructions. We successfully constructed the BAC-Tol2 vectors containing target genes. Each vector contained egfp report gene with UBC promoter, Neomycin resistant gene for cell screening and two loxp elements for resistance removing after transfected into cells. The bacterial artificial chromosome-Tol2 vectors showed a high efficiency of transfection that can reach 1% to 6% with a highest efficiency of 10%. We also obtained Cashmere goat fibroblasts integrated exogenous genes (kap6.3, kap8.1 and bmp4) preparing for the clone of Cashmere goat in the future. Our research demonstrates that the insertion of Tol2 transposons into bacterial artificial chromosomes improves the transfection efficiency and accuracy of bacterial artificial chromosome error-free recombination.
Animals ; Bone Morphogenetic Proteins ; genetics ; Chromosomes, Artificial, Bacterial ; DNA Transposable Elements ; Fibroblasts ; Goats ; genetics ; Keratins ; genetics ; Transfection

To construct an HSV-1 vector vaccine carrying HIV-1 antigens, HIV-1 gp160, gag, protease and the expression elements were chained together, and then inserted into the internal inverted repeat sequence region of HSV-1 by bacterial artificial chromosome technology. Firstly, HIV-1 gp160 (including type B and C), gag and protease genes were cloned into pcDNA3 in series to generate the pcDNA/gBgp and pcDNA/gCgp, then the recombinant plasmids were transfected into 293FT cells, and HIV-1 antigen was detected from transfected cells by Western blotting. Then the expression cassettes from pcDNA/gBgp and pcDNA/gCgp, comprising HIV-1 antigen genes and expression elements, were cloned into pKO5/BN to generate the shuttle plasmids pKO5/BN/gBgp and pKO5/BN/gCgp. The shuttle plasmids were electroporated into E. coli cells that harbor an HSV-BAC, the recombinant bacteria were screened, and the recombinant DNA was extracted and transfected into Vero cells. The recombinant virus was purified through picking plaques, the virus' DNAs were identified by Southern blotting; HIV-1 antigen was detected from the recombinant HSV-1 infected cells by Western blotting, and the virus' replication competent was analyzed. As the results, gp160 and gag proteins were detected from 293FT cells transfected with pcDNA/gBgp and pcDNA/gCgp by Western blotting. The recombinant bacteria were generated from the E. coli electroporated with pKO5/BN/gBgp or pKO5/BN/gCgp. The recombinant HSV was purified from the Vero cells transfected with the recombinant DNA, the unique DNA fragment was detected from the genome of recombination HSV by Southern blotting; gp120 and gp41 were detected from the infected cells by Western blotting, and the recombinant HSV retained replication competent in mammalian cells. The results indicate that the recombinant HSV carrying HIV-1 gp160, gag and protease genes was generated, the virus retains replication competent in mammalian cells, and could be used as a replicated viral vector vaccine.
Animals ; Cercopithecus aethiops ; Chromosomes, Artificial, Bacterial ; DNA, Recombinant ; genetics ; DNA, Viral ; genetics ; Escherichia coli ; HIV Antigens ; genetics ; immunology ; HIV Envelope Protein gp160 ; genetics ; immunology ; HIV Protease ; genetics ; immunology ; Herpes Simplex Virus Vaccines ; immunology ; Herpesvirus 1, Human ; physiology ; Plasmids ; Transfection ; Vero Cells ; Virus Replication ; gag Gene Products, Human Immunodeficiency Virus ; genetics ; immunology

Interleukin-7 (IL-7) is an essential cytokine for T cells. However, IL-7 is not produced by T cells themselves such that T cells are dependent on extrinsic IL-7. In fact, in the absence of IL-7, T cell development in the thymus as well as survival of naive T cells in the periphery is severely impaired. Furthermore, modulating IL-7 availability in vivo either by genetic means or other experimental approaches determines the size, composition and function of the T cell pool. Consequently, understanding IL-7 expression is critical for understanding T cell immunity. Until most recently, however, the spatiotemporal expression of in vivo IL-7 has remained obscured. Shortage of such information was partly due to scarce expression of IL-7 itself but mainly due to the lack of adequate reagents to monitor IL-7 expression in vivo. This situation dramatically changed with a recent rush of four independent studies that describe the generation and characterization of IL-7 reporter mice, all utilizing bacterial artificial chromosome transgene technology. The emerging consensus of these studies confirmed thymic stromal cells as the major producers of IL-7 but also identified IL-7 reporter activities in various peripheral tissues including skin, intestine and lymph nodes. Strikingly, developmental and environmental cues actively modulated IL-7 reporter activities in vivo suggesting that IL-7 regulation might be a new mechanism of shaping T cell development and homeostasis. Collectively, the availability of these new tools opens up new venues to assess unanswered questions in IL-7 biology in T cells and beyond.
Animals ; Biology ; Chromosomes, Artificial, Bacterial ; Consensus ; Cues ; Homeostasis ; Indicators and Reagents ; Interleukin-7 ; Intestines ; Lymph Nodes ; Mice ; Organothiophosphorus Compounds ; Skin ; Stromal Cells ; T-Lymphocytes ; Thymus Gland ; Transgenes

To construct the plasmid of BAC-HSV-1 with GFP reporter gene and research the biological property of its infectious progeny virus. We constructed the plasmid C223-UL43-left-arms-UL47-right-arms which carried the homologous sequences of HSV-1. Liposome embedding method was used to transfect HSV-1 genome and the plasmid C223-UL43-left-arms-UL47-right-arms linearized by Mlu I digestion into Vero cells. After the successful homologous recombination in the eukaryotic cells, the recombinant BAC-HSV-1 with GFP reporter gene was generated. Then, the positive CPE were taken by plaque purification and by hirt extraction during the moment of the circularization of HSV-1 DNA, and the plasmid of BAC -HSV-1 was acquired. Electroporation was used to transfect the BAC -HSV-1 into DH10B, and then the single colonies of interest were confirmed both by MluI digestion and PCR. Experimental group and the control group cells were given BAC-HSV-1 plasmid and HSV-1 genomic DNA respectively to produce the BAC-HSV-1 and HSV-1 progeny virions. Vero cells were inoculated with the progeny virions at MOI = 0.1 and then a TCID50 assay was performed to determine the titers of virons in the two groups at 48 hours post inoculation. The plasmid BAC-HSV-1 was successfully constructed by the restriction enzyme analysis and the PCR. The titers of progeny virions were calculated by the TCID50 assay. No significant difference in the titers of virions between two groups was observed (P > 0.05). The infectious BAC-HSV-1 shuttle virus/plasmid between eukaryotic and prokaryotic cells was successfully constructed.
Animals ; Cercopithecus aethiops ; Chromosomes, Artificial, Bacterial ; Green Fluorescent Proteins ; genetics ; Herpesvirus 1, Human ; genetics ; pathogenicity ; Recombination, Genetic ; Vero Cells

Genetic manipulation of human pluripotent stem cells (hPSCs) provides a powerful tool for modeling diseases and developing future medicine. Recently a number of independent genome-editing techniques were developed, including plasmid, bacterial artificial chromosome, adeno-associated virus vector, zinc finger nuclease, transcription activator-like effecter nuclease, and helper-dependent adenoviral vector. Gene editing has been successfully employed in different aspects of stem cell research such as gene correction, mutation knock-in, and establishment of reporter cell lines (Raya et al., 2009; Howden et al., 2011; Li et al., 2011; Liu et al., 2011b; Papapetrou et al., 2011; Sebastiano et al., 2011; Soldner et al., 2011; Zou et al., 2011a). These techniques combined with the utility of hPSCs will significantly influence the area of regenerative medicine.
Cell Line ; Chromosomes, Artificial, Bacterial ; genetics ; Deoxyribonucleases ; genetics ; Dependovirus ; genetics ; Gene Targeting ; methods ; Genetic Engineering ; methods ; Genetic Vectors ; Genome, Human ; Humans ; Mutagenesis, Insertional ; Mutation ; Plasmids ; Pluripotent Stem Cells ; cytology ; metabolism ; Zinc Fingers ; genetics

EphA/ephrin-A mediated signaling has emerged as a key mechanism regulating axon guidance and topographic mapping, particularly in the well-characterized visual system from the retina to the superior colliculus (SC). In this study, EphA8 bacterial artificial chromosome (BAC) was manipulated to contain a floxed eGFP and human ephrin-A5 expression cassette using homologous recombination method. In the mice containing the recombinant BAC, it was shown that GFP is expressed in an anterior>posterior gradient in the SC. Furthermore, when these mice were crossed with the transgenic mice expressing Cre under the EphA8 promoter, it was evident that a GFP expression cassette was eliminated, and that human ephrin-A5 was ectopically expressed in the anterior region of the SC. This transgenic model would be useful to analyze the role of ephrin-A5 in the SC during the retinocollicular topography formation.
Animals ; Axons ; Chromosomes, Artificial, Bacterial ; Ephrin-A5 ; Homologous Recombination ; Humans ; Mice ; Mice, Transgenic ; Retina ; Superior Colliculi