Homology of DV genes

Question 1

Are there homologous zygotic DV genes in mammals?

Answer 1

Drosophila - Sog (ventral) and Dpp (dorsal)
Mice - Chordin (dorsal) and BMP4 (ventral)
Structural and functional conservation (despite flipping of sides) over years of phylogeneitc divergence therefore it is considered an example of deep homology.

Question 2

Are there homologous maternal DV genes in mammals?

Answer 2

Toll, pelle, cactus and dorsal have mammalian homologues but play no role in patterning. Involved in innate immunity. Perhaps function has coopted.