pastor lecture 2 Flashcards
what happens when screening for temperature sensitve mutants at high temp?
-some cells die at high temp, indicating they are the temp sensitve mutants
how many cells exits in adult vs die durinig development in C elegans?
-959 cells in adult
-131 die during development
What type of cells were not swalowed up?
-the ced (cell death mutants) dont get swalloed up which provides a tool to study the apoptotic pathway
What type of ced is crucial for apoptosis/
ced-3 is crucial for apoptosis to occur
What happens in an egl-1 mutant?
What was occurring?
What saved phenotype?
-egg laying mutant causes eggs to form in the hermaphordite but undergo apoptosis like a male
-apoptosis was occuring when it wasnt supposed to
-ced-3
What ceds initiate cell death?
What caused excess cell death when mutated?
-ced-4 and ced-3
-ced-9, it is a positive regulator cell survival that would inhibit ced-3 and ced-4 activity, but when mutated it causes cell death
What is homologous in humans to ced-9?
-ced-9 mutant mapped to bcl-2 which is an oncogene overexpressed in b-cell lymphoma)
How would you test the expression of human bcl in c.elegans?
What would you introduce, what is the promoter for?
What do you clone?
-put human bcl-2 in c elegans
-introduce gene expression vector which has promoter into c.elegans
-has a promter for HSP16 (turns on if increase in temp)
-clone in cDNA for ced-9 and bcl-2 gene
What happens when hsp-ced-9 construct is in contact with heat shock?
What about hsp-bcl-2
-hsp-ced-9=neurons surve that shouldnt have
-hsp-bcl-2=large aount of worms get extra cells
what is egl-1 like in the apoptosis pathway?
What is analogous to ced-9?
egl-1 is like BAK and BAX which are pro apoptotic proteins
-bcl-2 is analogous
What is ced-4 analogous to, what does this part activate?
What does CASP9 activate?
-ced-4 is analogous to APAF1 which activates procasp9
-proCASP3 leading to CASP3 which is analogous to ced-3 which kills cells
where can apoptotic signals come from?
What stimulates the internal signal?
they can come from internal or extrnal parts of the cell
-TNF which stimulates CASP8 for internal
What does lin14 mutant cause?
What about excess Lin14?
-causes early shutoff of larva stage
-excess causes early larval pathway to be constantly repeated
What are lin14 and lin4?
What does lin4 loss of function cause
-what is purpose of lin 4?
-they are heterochronic mutants (developmental time mutants)
-lin4 loss of function=lin14 gain of function
-lin4 only purpose is to block expression of lin14
-no lin4=too much lin14
What type of lin 14 is always present?
What does lin 4 work as?
the lin 14 transcript is always present
-it works as an RNA since it doesnt code for a protein