Differential Gene Expression and Regulation Flashcards
What does differential gene expression allow?
different cells to have different functions
How many chromosomes do all human cells have?
22 pairs of autosomal and 1 pair of sex
Which cell types have gene amplification, gene loss and gene rearrangement?
some immune cells and tumour cells
What can differentiated cells do in many types of plants?
de-differentiate so that a single cell can form a clone of progeny cells that later give rise to an entire plant
What are the 4 conclusions of differential gene expression?
- not all genes are expressed in any single cell
- different sets of genes are expressed in different types of cells
- the same gene may be expressed at different levels in different types of cells
- the same gene may be expressed at different levels in the same cell but under different circumstances
How can differential mRNA expression be shown?
by transcriptomic analyses (heat map)
How can differential protein expression be shown?
2D gel electrophoresis analyses
How can the same protein have different isoforms?
post-translational modifications
What are housekeeping genes?
genes that are expressed in all types of cells for basic cellular structures and functions
What are tissue-specific genes?
genes that are expressed in one or a few tissues to give the cell its specific phenotype
What does RNA-seq do?
- generate a large number of short sequence tags that can be mapped to the genome and counted for quantitative analyses of RNA expression
- provide information on the transcription start site, intron/exon junction and differential RNA splicing
What are 4 the steps of RNA-seq?
- isolate RNA
- convert RNA to cDNA
- prepare the sequence library
- sequence the RNA on an NGS platform
What are characteristics of cell differentiation?
- cells become different through the synthesis of different sets of mRNAs and proteins
- each type of cell synthesises a few characteristic and specialised proteins at high abundance
- cell differentiation is usually stable and irreversible
What does the final level of a protein in a cell depend on?
- efficiency of each step
- rates of degradation of the RNA and protein molecules
What must happen in eukaryotes before mRNA can be translated?
- 2 ends of the RNA are modified
- introns are removed by splicing
- resulting mRNA is transported from the nucleus to the cytoplasm
