How are the HOM/hox gene expression patterns in developing fruitfly and mouse embryos similar?
The order of expression, front to back, in the embryos is identical, and they are expressed in similar positions in these embryos. c. HOM and hox proteins have some sequence similarities. The arrangements of HOM and hox genes on the DNA are also similar. Explain how these observations relate to metazoan evolution. Metazoans have complex body plans. There needs to be a genetic program to establish the pattern of embryonic parts. HOM/hox genes may have evolved from an early set of control genes that made this level of complexity possible. • (10 pts) The phylogenetic tree for selected animal types is shown below. The numbered circles correspond to adaptations inherited by all descendants to the right of that point. Fill in the blank beside each adaptation in the list below with the number corresponding to the position on the tree where that adaptation appeared. (There are only 5 answers!) Protostomate pattern = 5 Endoderm + Ectoderm = 3 Coelom = 6 Deuterostomate pattern = 7 Mesoderm = 4 •
