Genome size (Lucy) Flashcards
(42 cards)
Why does genome size matter?
It determines how much sequencing you need to do to get a complete genome seq
How much does it cost to seq a human genome?
Costs around £100 to seq single nucleotide variants (3x10^9 bp)
(More if we want telomere to telomere (T2T) contiguity & structureal variants)
How big is a typical protein?
About 333 amino acids in length
(So requires ~1kb (1000bp) of coding info)
Are genomes of complex multicellular organisms larger than those of simple unicellular organisms?
NO
What is the genome size and gene number for E.coli?
Genome size = 4.5Mb
Gene number = 4,300
What is the genome size and gene number for S.cerevisiae?
Genome size = 15Mb
Gene number = 5,700
What is the genome size and gene number for C.elegans?
Genome size = 100Mb
Gene number = 18,400
What is the genome size and gene number for D.melanogaster?
Genome size = 180Mb
Gene number = 13,600
What is the genome size and gene number for A.thaliana?
Genome size = 120Mb
Gene number = 15,000
What is the genome size and gene number for Humans?
Genome size = 3000Mb
Gene number = 19,000-20,500
What is the genome size and gene number for Zea Mays?
Genome size = 4,500Mb
Gene number = 15,000
What is the genome size and gene number for Amphiuma?
Genome size = 76,500Mb
Gene number = ~20,000
How many bp is in 1Mb?
1MB = 1000kb = 1,000,000bp
Give an example of a genome that is bigger than ours:
Lillies have a genome 30x bigger than ours (90,000, not one of the key numbers to remember)
How do our genes compare to e.coli?
We only have 4x as many genes as e.coli
What is the “C value paradox”?
C value paradox often stated as “no relationship between organismal complexity and genome size”
NOT always true
Give an example of the C value paradox being true:
Genome is 40X bigger in Protopterus aethiopicus (type of fish) than humans –> fish not more complicated
According to the C value paradox does genome size scale with the complexity of the organism?
Yes, when many organisms were compared there was an approx relationship - but there are outliers, these pose the C value paradox*
Data was plotted & showed a linear relationship (Megan if you could insert the graph would be fab xx)
*(The breakdown in the non linear relationship = the C value paradox)
What are the outliers in the C value paradox? (Linear relationship between genome size & complexity of organisms)
Lillies and lung fish (are the most comonly used examples of outliers)
What size can a bacterial genome range from?
Range in size from ~0.5Mb to 10Mb
(They DO NOT show any evidence for C value paradox)
Vary over 20 fold range: Mycoplasma genitalium 580kb - Sorangium cellulosum 13,000kb
What size is a small genome in a bacteria & what is its role generally?
Small genome (470 genes)
They are specialists, usually obligate parasites
What are the general structure of bacterial genomes
Bacterial genomes are mainly circular - soem are linear such as; Streptomyces coelicolor, Agrobacterium tumefaciens, Borrelia burgdorferi
What size is a large genome in bacteria & what is its role generally?
Large genome (~10,000 genes)
Metabolic generalists often undergoing some form of development
Are eukaryotic genomes always bigger than prokaryotic?
NO!!
Eukaryotic genomes are not always bigger than prokaryotic genomes
