Coding 3 & 4 Flashcards
How is the genome in each somatic cell related?
The genome in each somatic cell made from the same fertilized egg are identical
What happens to unexpressed genes?
Nothing they are not mutated, destroyed, or expressed
What are the 4 levels of regulation?
- Transcription makes pre-mRNA
- Pre-mRNA processing to mature mRNA
- Mature mRNA leaves the nucleus to be translated
- Protein processing post-translation
How was genomic equivalence determined?
Through Dolly
What can be concluded from different areas puffing at a time to produce RNA?
That RNA was being produced in different areas
What is SCNT?
Somatic cell nuclear transfer is a method that was used to determine the reprogramming of a nucleus into a whole organism to determine genomic equivalence
What is genomic equivalence?
When one differentiated cell becomes another differentiated cell
What were the steps to making Dolly?
- From the oocyte donor the egg was removed
- The DNA was extracted from the donated oocyte
- The DNA from the mammary gland of the donor was taken and put into the enucleated oocyte
- The oocyte now with a nucleus was put in a serrogate to grow
- Dolly was born
- Dolly then became a sexually mature adult and gave birth normally
What is the function of transcription factors?
To stabalize RNA polymerase II
What is a cis-regulatory element?
When the transcription factor binds to a region on the same chromosome
What are CREs that promote transcription?
Enhancers
What are CREs that repress transcription?
Repressors
What is the Poly-A tail?
This is a tail of adenosines that are added to the 3β end and is used to prevent degradation
What is a chromatin?
A region of DNA with its associating histones
What are nucleosomes?
A molecule with 8 histones 2x(H2A, H2B, H3, H4) with DNA wrapped around it
What is heterochromatin?
When the DNA is wrapped around the histones very tightly
What is the euchromatin?
When the DNA is wrapped around the histones very losely
What are exons?
These are the coding regions of the DNA that can be translated or transcribed
What are introns?
These are the noncoding regions of DNA that is not transcribed or translated
What is the 5β Cap?
This is a 5β modification that protects the mRNA from exonucleases
What are CpG islands?
This is a region that exists before the promoter where the basal transcription factors bind and recruit RNA pol II
How do enhancers promote transcription?
Enhancers promote activation by binding to transcription factors and bending the DNA to bridge the synthesis of mRNA
What is epigenetics?
This is modifying gene expression
What does methylation do?
Methylation increases packing and leads to heterochromatin by methyltransferase
What does unmethylation do?
Demethylation decreases packing and leads to euchromatin by demethyltransferase
What does acetylation do?
Histone acetyltransferase adds acetyl groups which counters the negative charge of the DNA and that leads to euchromatin
What does deacetylation do?
Histone deacetyltransferae removes acetyl groups and leads to heterochromatin
Which lysines are associated with activation due to methylation?
4, 38, 70
Which lysines are associated with repression due to methylation?
9 and 27
What does MeCP2 do?
MeCP2 recognizes methylated cytosine in DNA which recruits methyl transferase Dnmt3 to increase packing or histone deacetylase to increase packing
What is a DNA binding domain?
These often classify major transription families and the DNA binding domain recognizes a particular DNA sequence in the enhancer
What is a trans-activating domain?
Trans activating domain can activate or suppress the gene transcription
What is a protein-protein interaction domain?
This allows transcription factors to be modulated by transcriptional co-regulators
How is a hemoglobin produced?
The beta globin gene is expressed the pre-mRNA containing exons and introns cap, and tail are processed and the beta globin protein is inactive until its modified with an alpha globin and heme to form an active hemoglobin