CELL201 Lecture Notes - Lecture 17: Gel Electrophoresis, Noncoding Dna, Ring Chromosome
Document Summary
Dna, chromosomes and the nucleus: genome size is usually expressed in base pairs (bp, haploid: one copy of each chromosome. Looking at karyotypes allows the detection of some genetic diseases: fish: isolate a nucleus, where chromosomes are condensed, use nuclear probe labelled with fluorescent dye, probe sticks to certain region of the chromosome, can find out a gene. Sequences of gene is same but there can be translocations. Problem not seen in sequence but in karyotype, genes are in wrong contest: protein coding genes: less than 2% of the 3 mbp (haploid) genome, repeats: Large size of eukaryotic genome: junk dna and repeats. Tandemly repeated sections can be looked at to figure out identity of person, forensic analysis, combination of different tandem repeats. Transposable elements: move around the genome and leave copies (alu elements: problems with repetitive dna: expansion of repetitive dna, triplet repeat amplification: Huntington"s disease, cag- glutamine repeats: dna sequencing: