Hedgehog plays a vital role in most ectodermal organs such as teeth, hair follicles etc.
Interestingly this doesn't seem to be the case with mammary gland development.
http://dev.biologists.org/cgi/content/full/133/18/3661
Gli2, a transcription factor and target of Hedgehog signalling is expressed during mammary development, and the same is true for gli3. Gli3 being a translational repressor for Hh target genes and gli2 acting as an Hh target inducer. Oh the fun they have together!
This fun is usually reflected in gli1 expression levels since gli1 activity reflects the outcome of gli2 activation and gli3 repression of Hh target genes.
No gli1 in the embryonic mammary bud though or in any stage.
make a transgenic mouse where gli3 is knocked out (gli3 -/-) and we see aberrant placode development and the lack of two pairs of mammary buds. Quite radical.
So they made another mouseline where both Gli2 copies were replaced by Gli1 (under the gli2 promotor) and voila...the 2 mammary buds disappear again!
so in short:
Marvelous.
Interestingly this doesn't seem to be the case with mammary gland development.
http://dev.biologists.org/cgi/content/full/133/18/3661
Gli2, a transcription factor and target of Hedgehog signalling is expressed during mammary development, and the same is true for gli3. Gli3 being a translational repressor for Hh target genes and gli2 acting as an Hh target inducer. Oh the fun they have together!
This fun is usually reflected in gli1 expression levels since gli1 activity reflects the outcome of gli2 activation and gli3 repression of Hh target genes.
No gli1 in the embryonic mammary bud though or in any stage.
make a transgenic mouse where gli3 is knocked out (gli3 -/-) and we see aberrant placode development and the lack of two pairs of mammary buds. Quite radical.
So they made another mouseline where both Gli2 copies were replaced by Gli1 (under the gli2 promotor) and voila...the 2 mammary buds disappear again!
so in short:
Marvelous.
