Class 3 Hox genes in insects and the origin of zen.
We have cloned, from a beetle and a locust, genes that are homologous to the class 3 Hox genes of vertebrates. Outside the homeobox they share sequence motifs with the Drosophila zerknüllt (zen) and z2 genes, and like zen, are expressed only in extraembryonic membranes. We conclude that the zen genes of Drosophila derive from a Hox class 3 sequence that formed part of the common ancestral Hox cluster, but that in insects this (Hox) gene has lost its role in patterning the anterio-posterior axis of the embryo, and acquired a new function. In the lineage leading to Drosophila, the zen genes have diverged particularly rapidly.
Falciani
F
F
Department of Genetics, Wellcome/Cancer Research Campaign Institute, Cambridge, England.
Hausdorf
B
B
Schröder
R
R
Akam
M
M
Tautz
D
D
Denell
R
R
Brown
S
S
D000595:Amino Acid Sequence; D000818:Animals; D005075:Biological Evolution; D001517:Coleoptera / Q000196:embryology / Q000235:genetics*; D029721:Drosophila Proteins; D018507:Gene Expression Regulation, Developmental; D005801:Genes, Homeobox; D017344:Genes, Insect; D006110:Grasshoppers / Q000196:embryology / Q000235:genetics*; D018398:Homeodomain Proteins; D017403:In Situ Hybridization; D008969:Molecular Sequence Data; D009024:Morphogenesis; D012333:RNA, Messenger / Q000235:genetics; D012097:Repressor Proteins / Q000235:genetics*; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
D029721:Drosophila Proteins; D018398:Homeodomain Proteins; D012333:RNA, Messenger; D012097:Repressor Proteins; C085607:Zen protein, Drosophila