Control of Metamorphosis by Internal and EXternal Factors emperature, Light, Stress, Brain etc Temperature day degrees) Critical size matched (availability of food Light(photoperiod) Chemicals Amount of moisture(湿度) Stress: mutagens, predators(肉食者),etc
Control of Metamorphosis by Internal and External Factors Temperature (day degrees) Critical size matched (availability of food) Light (photoperiod) Chemicals Amount of moisture（湿度） Stress: mutagens, predators（肉食者）, etc. Brain Temperature, Light, Stress, etc
Ecdysone: "Molting Hormone Steroid hormone produced by prothoracic gland (lipid soluble, passes through cell membrane to the nucleus) Activates early response genes (TFs)and then late response genes (may cause differentiation, cell proliferation and migration, structural changes, apoptosis) Primes insect to respond to second hormone EH Ec Early Response Late Response Transcription Transcription initiated Factors by Transcription Factors USP Binding Sit
Ecdysone: “Molting Hormone” Steroid hormone produced by prothoracic gland (lipid soluble, passes through cell membrane to the nucleus) Activates early response genes (TFs) and then late response genes (may cause differentiation,cell proliferation and migration, structural changes, apoptosis) Primes insect to respond to second hormone, EH Ec USP Binding Site Early Response: Transcription Factors Late Response: Transcription initiated by Transcription Factors
Chromosome Puffing in flies Observed in giant salivary gland chromosomes (no cell division after replication) Can be inhibited by actinomycin(放线菌素D) Puffing is where transcription is occurring Ecdysone can be detected by fluorescent antibodies localized to the puffing Early puffs and late puffs seen in larva to pupa 兰三 and pupa to adult molt 燕空
Chromosome Puffing in Flies Observed in giant salivary gland chromosomes (no cell division after replication) Can be inhibited by actinomycin(放线菌素D） Puffing is where transcription is occurring. Ecdysone can be detected by fluorescent antibodies localized to the puffing Early puffs and late puffs seen in larva to pupa and pupa to adult molt
A2 A3 B EcR pre-mRNA Alternative splicing A1A2A33456 B1B23 B23456 EcR mRNA M)h DNA-binding site i Ecdysone-binding site C N N EcR-A protein EcR-B1 protein EcR-B2 Protein Alternative Splicing of Ecdysone Receptor Pre mRNA Creates several forms of the ec Receptor Allowing Cell Type Specific Ecdysone Response
Alternative Splicing of Ecdysone Receptor PremRNA Creates Several Forms of the EcReceptor Allowing Cell Type Specific Ecdysone Response
Regulation of JH Levels Juvenile hormone Ecdysone Larva Pupa Adult Low= larva stage; Medium JH levels= pupa stage, No JH= adult stage Rate of release limited by synthesis Amounts of JH also regulated by protein degradation and methyltransferase levels(can be protected by jh binding proteins degraded by JH esterase
Low = larva stage; Medium JH levels = pupa stage; No JH = adult stage Rate of release limited by synthesis Amounts of JH also regulated by protein degradation and methyltransferase levels (can be protected by JH binding proteins, degraded by JH esterase) Regulation of JH Levels Amount of Hormone Larva Pupa Adult Juvenile Hormone Ecdysone