CSB349H1 Lecture Notes - Lecture 1: Inverted Repeat, Satellite Dna, Minisatellite
14 May 2018
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Lecture 1(a): Genome Repeats
What is in the (human) genome?
• Build 35: 2.85 Gigabases, 10-5 error rate (1 in 100,000 is incorrect)
o “Build 35” = 35th time people tried to put the pieces of the human genome together
o Gigabase = 1,000,000,000 bases
ð Entire genome is ~3.08 Gigabases
o 200Mbases short; cannot be (not) sequenced
§ Most of this consists of heterochromatin
(telomeres, centromeres) and other
repetitive DNA
ð Most of our genome is not even human genes
o Repetitive elements make up 45% of the genome
o Only ~20,000 protein coding genes making up 1.5% of the genome
Types of Repetitive DNA Sequences:
1. Tandemly Repeated Sequences
a) Satellite DNA
b) Minisatellite DNA
c) Microsatellite DNA
§ Repeat that occur adjacently to each other
2. Interspersed Repeated Sequences
a) Transposons (~1-2kb)
b) Miniature Inverted Repeat Transposable Elements (MITES) (<0.5kb)
c) SINES (<0.5kb)
d) LINES (>5kb)
§ Repeats that occur randomly in the genome
Document Summary
What is in the (human) genome: build 35: 2. 85 gigabases, 10-5 error rate (1 in 100,000 is incorrect, build 35 = 35th time people tried to put the pieces of the human genome together, gigabase = 1,000,000,000 bases. Entire genome is ~3. 08 gigabases: 200mbases short; cannot be (not) sequenced. Most of this consists of heterochromatin (telomeres, centromeres) and other repetitive dna. Most of our genome is not even human genes: repetitive elements make up 45% of the genome, only ~20,000 protein coding genes making up 1. 5% of the genome. Types of repetitive dna sequences: tandemly repeated sequences, satellite dna, minisatellite dna, microsatellite dna. Repeat that occur adjacently to each other: interspersed repeated sequences, transposons (~1-2kb, miniature inverted repeat transposable elements (mites) (<0. 5kb, sines (<0. 5kb, lines (>5kb) Repeats that occur randomly in the genome. Tandem repeats: satellite dna, repeat units can range between 10"s to 100"s of base-pairs found in large clusters (millions) making up a large percentage of our genome.
