In brief, 1 mL of sponge liquid was washed twice with PBS containing 0.1% bovine serum albumin; as an inhibition control, pellet was resuspended in 50 [micro]L PBS with 0.1% bovine serum albumin containing bicoid
In recently evolved systems involving regulation of multiple genes like the Bicoid
and Dorsal morphogens, it would take a large number of random sequence changes in cis-elements during evolution in a specific world to bring about the specific pattern of gene expression required.
Dawson, "The effect of reactions on the formation and readout of the gradient of Bicoid
," Physical Biology, vol.
Cho-Park et al., "A new paradigm for translational control: inhibition via 5,-3f mRNA tethering by Bicoid
and the eIF4E cognate 4EHP," Cell, vol.
They focused on one protein, Bicoid
(Bcd), which is expressed in a gradient with highest levels at the end of the embryo that will become the mature fly's head.
The genes operating early during Drosophila segmentation--such as bicoid
, hunchback, and knirps--have not been conserved in other arthropods, and likely are a late innovation of the insects.
The genes orthodenticle and hunchback substitute for bicoid
in the beetle Tribolium.
Maternal expression relaxes constraint on innovation of the anterior determinant, bicoid
. PloS Genetics 1: 527-530.
Among the few maternal mRNAs that have been characterized, bicoid
, oscar and nanos are associated with anteroposterior fate in Drosophila, and VGA defines the vegetal pole in Xenopus.
Cooperative control of positional information in Drosophila by bicoid
and maternal hunchback.
Then, those RNA messages call for the production of a protein called bicoid
. A high concentration of bicoid
in one part of the embryo activates the genes needed for development of the head and thorax, says Hazelrigg.
These genes, bicoid
, zen, and fushi-tarazu (ftz), serve roles in development different from those of the canonical Hox genes.