Biology 1002B Lecture Notes - Lecture 4: Human Genetic Variation, Euchromatin, Noncoding Dna
24 Oct 2016
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Cell is arrested at metaphase: chromosomes most compact, stained with dye to produce banding pattern. Identify all individual chromosomes: 22 pairs of autosomes, 2 sex chromosomes. Dye stains in a consistent fashion: pattern compared to standard. Approximate size of the genome (3 billion base pairs) known. The sequence of a number of genes and genomic regions. Human genome project goal- sequence and characterize the human genome. Draft sequence: missing 30% of genome. Finished sequence: 1% euchromatin missing, 341 gaps, 1/100,000 errors. Some regions of the genome are difficult to sequence. Segmental duplications (blue: >1kb of dna with >90% similarity to each other. Half of the human genome is repetitive dna: much is retroviral in origin. Efforts continue to close sequence gaps: primary focus on euchromatic gaps. 22,287 gene loci: 19,438 known, 2,188 predicted, 34 mb of dna. ~7 individual genomes sequenced in each (public and private) project. Generated a reference sequence: sequence which was most common at each nucleotide.
