Bart - Metamorphosis Genes Flashcards
What is the role of ecdysone in insect metamorphosis?
Ecdysone triggers molting and metamorphosis by regulating gene expression and developmental processes in insects.
How does juvenile hormone (JH) influence the type of molt in insects?
High JH levels promote larval molting, while low JH levels trigger pupation and metamorphosis.
What happens during the metamorphic transition when JH levels drop?
A drop in JH levels leads to the initiation of pupation and the metamorphic transition to adulthood.
Describe the role of 20-hydroxyecdysone (20E) in gene regulation during insect development.
20E binds to the ecdysone receptor complex, activating early and late response genes crucial for metamorphosis.
What is the function of the Ultrabithorax (Ubx) gene in segment identity?
Ubx specifies the identity of thoracic and abdominal segments, particularly influencing the formation of halteres.
What distinguishes wing discs from other imaginal discs in Drosophila?
Wing discs are larger and express the vestigial gene, which is crucial for wing development.
How does the BMP signalling gradient influence wing cell fate?
The BMP gradient, created by Dpp and Gbb, regulates cell proliferation and specifies cell fates based on the levels of pMad.
Describe the function of paracrine signalling in Drosophila wing development.
Paracrine signaling, involving factors like hedgehog and wingless, regulates local cell proliferation and differentiation in the wing disc.
What are the main types of imaginal cells in
Drosophila?
The main types include cells of imaginal discs (forming adult structures), histoblasts (forming the abdomen), and clusters of imaginal cells within organs.
How do Hox genes specify segment identity in Drosophila?
Hox genes determine segment identity by encoding transcription factors that regulate gene expression patterns specific to each segment.
