Chapter 10 Flashcards
amount of DNA in a haploid cell
C-value
amount of DNA not correlated with complexity
C- value Paradox
Lungfish have how many time the DNA of humans
40x
the first genome sequencing
bacteriophage MS2 ( RNA virus)
- 1.8 terabases of data — 16 human genomes’ worth — per three-day run
- 18,000 human genomes per year. Each genome 30x
- Machine is $1,000,000, –but genome ~$1,000
Illumina HiSeqX
- Connects to a computer through USB
- Uses Nanopore technology - draw DNA through a small hole
- Each chip would be about $1000
- Can’t handle big genomes yet
Oxford Nanopore MinION
C-value paradox
- Even though about the same number of genes in organisms
- Larger % noncoding in Eukaryotes
move sections of DNA around, - may drive and increase in genome size over time
transposons
selection for replication speed, small cell size, and energetic efficiency may favor reductions in size over time
transposons
- Evolutionary history
- Drosophila has lots of active transposons
- Humans had them in past, but few active now
balance of these forces leads to C-value paradox
Increase in DNA leads to increase in…
cell size
number of protien -coding genes
G-values
does not appear correlated with complexity
G-value Paradox
it is all about the regulatory genes
G-value Paradox
Bind to specific regions of DNA in order to regulate when where and to what degree specific genes are expressed
-Transcription factors
often act upon another
Transcription factors
Degree of regulatory control of non-coding regions
Increase # regulatory elements with C-value
One protein-coding gene ≠ one protein
G-value Paradox
put the exons together in different ways
- can increase the diversity of an organisms functional proteins
alternative splicing
-humans: more alternative spliced genes and more introns than nematodes
changes to newly transcribed RNA
Posttranscriptional modification
- pre-mRNA
- Alternatively spliced mRNA
- Different protein isoforms
steps of alternative splicing
RNA or DNA
Single linear, set of linear, or circular chromosomes
The Viral Genome
Compact – RNA up to 30kb
Few proteins
DNA to 1mb
The Viral Genome
May have overlapping, but same reading frame genes
Or different reading frames
The Viral Genome
is a single-stranded positive-sense RNA virus with a genome composed of a single linear chromosome
SARS Coronavirus Single Stranded RNA