[p6, column 2, §2]
These pathways will “induce” either legs, antennas, halteres, or wings along the body by nucleation of appendage primordia at intersections of genetic boundaries. However, wings and halteres are more dorsal (hence the wings “on the back”), while antennas and legs are more ventral (hence legs hanging below the abdomen). Antennas can be genetically “upgraded” into legs, and halteres into wings, but more ventral appendages like legs cannot be morphed into more dorsal appendages, because the diﬀerence is not only a diﬀerence of genetic expressions: there is also a topological diﬀerence (what matters is both the nature of the proteins, and the spatial organization of the primordia).
How hard could it be to check for homeotic transformations of legs to wings, or halteres, that is: ventral to dorsal appendages ?
First paper on the results’
a ten years old paper1, cited by 130 (not really a secret, isn’t it?), direct access:
Ultrabithorax regulates genes at several levels of the wing-patterning hierarchy to shape the development of the Drosophila haltere, Scott D. Weatherbee, Georg Halder, Jaeseob Kim, Angela Hudson, and Sean Carroll, Genes Dev. May 15, 1998 12: 1474-1482; doi:10.1101/gad.12.10.1474
Figure 5 of the paper (click image to navigate to the source)
What really matters, is reality check, to avoid wishful thinking, wrong assertions and being __________2 in front of his colleagues.
1. Plenty of time to find it and read it for someone really interested by the subject.
2. Shall we play Hangman?