Biomedical subjects

R Jiao

Publications and source records attributed to R Jiao.

7 recordsLinked to original sources

PubMed2001

Headless flies generated by developmental pathway interference.

Ectopic expression of transcription factors in eye-antennal discs of Drosophila strongly interferes with their developmental program. Early ectopic expression in embryonic discs interferes with the developmental pathway primed by Eyeless and generates headless flies, which suggests that Eyeless is necessary for initiating cell proliferation and development of both the eye and antennal disc. Interference occurs through a block in the cell cycle that for some ectopic transcription factors is overcome by D-CycE or D-Myc. Late ectopic expression in cone cell precursors interferes with their differentiation. We propose that this developmental pathway interference is a general surveillance mechanism that eliminates most aberrations in the genetic program during development and evolution, and thus seriously restricts the pathways that evolution may take.

Animals↗

PubMed1996

Signal transduction pathways in guinea pig sperm.

Trifluoperazine (TFP), the antagonist of calmodulin (CaM), significantly stimulated the capacitation and acrosome reaction of guinea pig spermatozoa at the concentration of 10-100 mumol/L, independent of the external Ca2+. Forskolin, dbcAMP and caffeine evidently promoted the occurrence of acrosome reaction of spermatozoa at early capacitation stage (5 h) in nonsynchronous system but not in synchronous system. If the spermatozoa were capacitated for 15 h in synchronous system, the above three drugs significantly stimulated acrosome reaction in a Ca(2+)-independent manner. Protein kinase C activators, i.e. phorbol 12-myristate 13-acetate (PMA) and phorbol 12,13-dibutyrate (PDB) did not influence the occurrence of acrosome reaction of spermatozoa at early capacitation stage, but significantly increased the acrosome reaction rate in capacitated spermatozoa in a Ca(2+)-independent manner. In contrast, PKC inhibitor staurosporine significantly inhibited the occurrence of acrosome reaction.

Acrosome↗

PubMed1994

Nitrite reductase gene cloning of Amycolatopsis mediterranei U-32.

Southern blot analysis showed great homology existed between niaD (NR gene) of Aspergillus nidulans and A. mediterranei U-32 chromosome DNA. A 5.0kb PstI fragment from A. mediterranei U-32 complementary to A. nidulans niaD gene was cloned in E. coli NM522 using niaD as a probe. An identical DNA band was observed through back-hybridization of the cloned DNA fragment to PstI digest of A. mediterranei U-32 chromosome DNA. Its 2.1 kb SmaI-EcoRV fragment can only hybridize with total RNA from nitrate-cultured mycelium but not with that from ammonia-cultured mycelium. These data suggested that the cloned DNA fragment contains NR gene of A. mediterranei U-32. This is the first report on NR gene cloning from a aerobic bacterium. It was deduced from the molecular weight of the nitrate reductase that the coding sequence of NR gene is almost 1.5 kb in size. Further hybridization analysis indicated that the cloned DNA fragment covers the full-length NR gene of A. mediterranei U-32. We also constructed the physical map of the recombinant plasmid pJL1 with various restriction endonucleases, among them ten with no restriction site, six with unique site and two with double sites on the insert.

Actinobacteria↗

PubMed1992

Localization of adenovirus DNA by in situ hybridization electron microscopy.

Biotinylated deoxyadenosine triphosphate (dATP) (Bio-7-dATP) and 3H deoxythymidine triphosphate (dTTP) labeled adenovirus DNA were hybridized in situ to thin sections of Lowicryl K4M-embedded and whole-mount extracted HeLa cells infected with adenovirus. The biotinylated probe was detected by exposing the extracted cells or sections to antibodies against biotin followed by colloidal gold-conjugated secondary antibodies and then critical-point dried while 3H-dTTP labeled probe by electron microscopic autoradiography. On Lowicryl K4M sections, gold particles and silver grains were mainly restricted in the nucleus. Furthermore, whole-mount results suggested that replicating adenovirus DNA is localized on the nuclear matrix of its host cell. In this paper, the described non-radioactive procedures for hybrid detection offered several advantages: a) rapid signal detection; b) superior morphological preservation and spatial resolution; c) precise localization; and d) on Lowicryl K4M sections, signal to noise equivalent to radiolabeling.

Acrylic Resins↗

PubMed1992

Restriction mapping and localization of GL-7-ACA acylase gene.

This paper presents the results about the restriction mapping of recombinant plasmids pMR5 and pMR6 containing GL-7-ACA acylase gene from Pseudomonas sp. 130, gene localization and its expression under the control of different promoters, tet, tac or lac/tac, in Escherichia coli. The analysis of gel electrophoresis of pMR5 cleaved with several kinds of restriction enzymes indicated that there is no sites of EcoRI, HindIII and ClaI but the presence of following sites: one HpaI, two XhoI, three EamHI and four PstI on the cloned gene fragment. The restriction maps of pMR5 and pMR6 were determined by comparative digestion of various endonucleases. The gene of GL-7-ACA acylase was localized on a 3.0kb fragment of B2-B3-HpaI from the studies on a serial subcloning. Expression of subclones pMR9, pMR10 and pMR11 in E. coli was compared. Higher yield of acylase was obtained when the gene fragment was placed downstream of the tac promoter. The expression of Pseudomonas gene in E. coli was also discussed.

Amidohydrolases↗

PubMed1991

[The study of Bacillus sphaericus Ts-1 protoplast-plasmid transformation of electroporation].

This report gave the best conditions of Bacillus sphaericus Ts-1 protoplast-plasmid pHV33 electroporation. The highest transformation frequency and transformation efficiency induced by three pulse of 21 KV/cm and 10 microseconds duration applied at an interval of one sec., was 2.44 x 10(2) transformants/micrograms DNA and 3.16 x 10(-6) respectively. The saturated concentration of DNA absorbed by the protoplast was 5 micrograms DNA/10(9) cells/ml. By means of this method, pJB417, a recombinant mosquito larvicide clone, was introduced into B. subtilis 168M and B. sphaericus Ts-1. The transformants of B. subtilis 168M with biocide activity were obtained, but the toxicity of B. sphaericus Ts-1 was not increased.

Animals↗

PubMed1990

[The relationship of Sindbis virus assembly and the viral protein 6K with intermediate filaments].

The relationship of Sindbis virus (Sbv) assembly with intermediate filaments was studied by means of whole-mount and DGD embedment-free technique of EM together with the procedure of gentle extraction. In the early stage of Sbv infection, the "virus assembly center" was suspended in the intermediate filament network. In the late stage, the assembling and assembled virus nucleocapsids were associated with intermediate filaments. It is presumable that the virus nucleocapsids may move from the "virus assembly center" to cytoplasmic membrane along the intermediate filaments. Further study using immunolabelling technique indicated that the nonstructural protein 6K of Sbv was probably associated with intermediate filaments as well.

Cell Line↗