(Downloading may take up to 30 seconds.
If the slide opens in your browser, select File -> Save As to save it.)
Click on image to view larger version.

Fig. 1. Conditional inactivation of TrkA. (A) Diagram of the replacement vector
strategy used to generate the TrkAneo allele and re-activation of
TrkA expression by Cre recombinase. The pGKneobpA cassette flanked by loxP
sites was placed into intron 11. (B) Southern blot analysis of tail DNA from
three-week-old mice with a 5' external probe shows the switch of the
wild-type (WT) BamHI fragment from 12 kb (WT) to a 7 kb restriction fragment
(TrkAneo) after neo insertion. (C) Northern blot analysis of total
RNA extracted from Dorsal Root Ganglia (DRG) neurons of E13.5 embryos either
WT (+/+), heterozygous for the neo insertion (+/neo), homozygous for the neo
insertion (neo/neo), or homozygous for the allele after neo removal with
ß-actin cre (loxP/loxP), hybridized with a TrkA-kinase domain-specific
probe (exon 14-17). Note that neo insertion completely eliminates
TrkA-specific transcripts whereas TrkA-transcription is restored to WT levels
after neo-excision by Cre recombination. (D) RT-PCR analysis of the same
samples analyzed by northern blot. Specific primers for actin, neo, and TrkA
exon 10 and 14 were used. Samples were treated with (+) and without ()
RT. Note the complete absence of the 609 bp TrkA-specific PCR product in
TrkAneo/neo mice. (E) Wholemount lacZ staining of a
Rosa-26 E11.5 embryo with the T
1-cre transgene. Note the specific
staining in both central and peripheral nervous system. (F) lacZ
staining of sections from spleen, thymus and bone marrow of adult Rosa-26 mice
carrying the T
1-Cre (top panels) or a ß-actin-Cre
transgene with mosaic expression used as control (bottom panels)
(Ma et al., 2003). Cre
recombinase under the control of the T
-1 promoter is only expressed in
the nervous system (E) and not in organs of the immune system (F).