Lecture 8: Eukaryotic Genes File Flashcards
When/where a gene is expressed is directed by what two things?
- Promoter where RNA polymerase binds (to initiate transcription)
- Enhancers (enhancers usually 5’ - at the front)
DMD is the largest human gene? true or false, and where is it ?
TRUE, X chromosome
What does alternative splicing result in ?
results in a single gene coding for multiple proteins
What type of genes are homoetic genes ?
Developmental genes
Give an example of mutant homoetic genes
Fly body parts in the wrong places
Each homoetic gene encodes what ?
Each homoetic gene encodes a transcription factor
In flies homoetic genes are expressed in what manner ?
Segment specific manner (they have 180bp homeobox, which encodes a 60aa DNA binding domain )
What is the cause of four winged fly mutant
Mutation in Ubx gene, Ubx gene is expressed in wrong segment
Homeotic mutants are usually caused by….
mutations in their very large control regions
Changing order of genes causes ……
misexpression of genes (genes switched on in the wrong segment)
What are the haemoglobin subunits
2x beta-globin (6 genes arranged in tandem on chromosome 11)
2x alpha-globin (7 genes arranged in tandem on chromosome 16)
Why are haemoglobin genes clustered ?
They are expressed at different times (embryo ->fetus-> adult)
The immmune system is clustered on what chromosome ?
sixxxxxx
What does the MHC gene cluster encode ?
Histocompatability antigens
What is the function of histocompatability antigens ?
immune response, distiguish self and non self , tissue graft rejection, protect against pathogens
