Hox Genes & Segmentation Flashcards
What are rhombomeres
seven segments of tissue developed in the hindbrain of vertebrates
Describe the segmentation of drosophila
thorax; - T1-T3 and abdomen; - A1-A8
What does recessive mutations in the ultrabithorax gene cause
transformation of the third thoracic segment into the second thoracic
Describe a homeotic transformation
one structure is replaced by another
What is the function of Ubx
Ubx regulates the developmental programme of T3
What dos Ubx act as
selector genes to specify identity of halteres
Describe autonomous function
mutation affects cells in which it is present
What can cause an autonomous mutation
transcription factor and receptors
Describe non-autonomous function
mutation affects the cells around it
What can cause a non-autonomous mutation
signalling molecule
What do the imaginal discs give rise to in the fly
structures of the adult fly
What pathway does Ubx direct cells down
metathoracic pathway of development
What transformations does abdominal B cause
transformation of abdominal segments into a different identity
What genes make up the bithorax complex?
Ubx, AbdB and abdA
What is the homeobox
highly conserved motif
What does the homeobox code for
homeodomain
What is the homeodomain
sequence specific DNA binding motif
What does the arrangement of genes in the bithorax complex reflect
order of function along AP axis
Describe the expression of the bithorax complex
spatially restricted along AP part of animal
TRUE or FALSE - Bithorax complex is required for segmentation process
FALSE
What is the function of the Bithorax complex?
specify segmentation and body plan
What is the antennapedia complex required for
makes anterior type structures
What development does the antennapedia complex control
head and thoracic segments
What segment does the antennapedia complex control
T2
what do dominant mutations of the antennapedia complex cause
legs grow where the antenna should be
What do Hox genes code for
DNA binding proteins that regulate transcription
Describe the conservation of hox genes
highly conserved throughout evolution
