CSB349H1 Lecture Notes - Lecture 1: Copy-Number Variation, Dna Microarray, Reference Genome
14 May 2018
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Lecture 1(d): Genome Repeats
Short Interspersed Elements – Mechanism of Transposition:
• Alu is the most abundant SINE
o Does not code for transposase or integrase
o Do not code any protein or RNAPII promoter; they code for an RNAPIII promoter
ð Their mechanism of transposition is done by hijacking the LINES machinery
o Will hijack ORF1 and ORF2 to reverse transcribe and insert themselves in the genome
§ Will also rely on cellular mechanism to eliminate RNA/DNA hybrid
(same mechanism as LINE)
Summary:
Gene Copy Number Variation (CNV) & Dosage Effects:
• The relationship between the # of copies a gene is found and the impact it has on the
phenotype can be complicated:
o Linear Function:
§ 2 copies of homozygote dominant is the best
o Stoichiometric Titration:
§ Normal 1 copy of a gene is the best; but harmful if two copies
Just know that if we
have extra copies of
genes it can lead to
certain diseases
Repeats within genes
can lead to diseases
