Team:Evry/Biology/CellCharacterization/TransformationProtocol

From 2014.igem.org

Revision as of 13:13, 17 October 2014 by NoémieBC (Talk | contribs)

Transformation Protocol




Blabla chimio impossible


  • Washing test
    Blabla proto + schéma
    Table X: Results of washing test, number of CFU for the different washes.
    text to print if image not found


  • Voltage test
    Blabla proto+schéma
    Table Y: Results of voltage test, number of CFU for the different voltage.
    Table


  • Test with PSB1C3
    Blabla différents test+mutations envisagées
    plasmides testés (rappel des collabo)
    Figure
    Figure Z: Maps of PSB1C3.

    Blabla échec

  • Other plasmids tested

    Figure
    Figure N: Maps of PBBR1MCS and pRhoKHI-2.


  • Create a new plasmid
    After trying to transform Pseudovibrio denitrificans with the PSB1C3 whic didn't work, we had several hypothesis:
    -The promoter of the Chloramphenicol resistance gene doesn't work in our bacteria
    -The origin of replication doesn't work in our bacteria
    -There is a system degrading exogene DNA in Pseudovibrio
    To check these hypothesis, we chose to find specific constitutive promoter and origin of replication in another member of the genus Pseudovibrio, which has been sequenced, the FOBEG1 strain. (lien article)

    A strong constitutive promoter of FOBEG1 was looked for with the genome browser. Upstream sequences of vital and cell cycle independant genes were explored. We were interested by the transkelotase, key enzyme of the way of pentoses phosphates.
    We can suspect that this enzyme has to have a good constitutive promoter, or at least led a reliable and consequent expression. To be sure to have the whole promoter sequence, we exported the sequence (fasta format) from the beginning of the ORF of the transkelotase, until the end of the previous ORF. This sequence was amplified with primers 5 and 6 (see primers table in Protocols).

    After a PCR, we obtained a 6000pb band for Pseudovibrio ascidiaceicola, and no band for Pseuvibrio denitrificans. These PCR product was sequenced, as show in figure M.

    Figure
    Figure M: Result of promoter sequencing.

    Thus, there is 94.1% of identity between the transketolase promoter of the Pseudovibrio FOBEG1 strain ans the Pseudovibrio ascidiaceicola strain.

    For the replication origin, the aim was here to find the replication origin of the plasmid of the reference strain FOBEG1. In this way, repA, repB and repC genes were looked for on NCBI. Those three genes follow each other in the genome.
    This sequence was amplified with primers 49 and 50 (see primers table in Protocols).

    Figure
    Figure Q: Result of ORI amplification in Pseudovibrio denitrificans (Pd), Pseudovribrio ascidiaceicola (Pa) and E.coli DH5a.

    The negative control with E.coli DH5a confirms that there is no amplification. For Pseudovibrio strains, we obtain one band for Pseudovibrio denitrificans and two for Pseudovibrio ascidiaceicola.


    Meanwhile the plasmide of the transposase was tested, and the project to create a viable plasmide for pseudovibrio was abandoned (Transposons ).
    Moreover, our third hypothesis of a system which degrade exogen DNA was nourishing by BLAST data, and the presence of the enzyme EcoK1 in the genome (see section DNAseq in Cell Charactherizaion ). This enzyne is in deed kwnon to degrade DNA withour a certain pattern of methylation.