Eukaryotic genomes

Genome = All DNA in a cell

Mitochondria = 37 genes

Chloroplast = 140 - 400 genes

Nucleus = 20,000 - 25,000 genes

C value = Weight (picograms pg) of n

1 base pair (bp) = 660 Daltons

C value paradox = no relationship between c value and complexity of organism

Determing genome size

Extract DNA from known number of cells, determine amount of DNA, amount/no of cells

Stain DNA with fluorescent tag and use fluorescence microscopy to estimate

Human nuclear genome

Genic 38%

Non genic 62%

Genes 2%

Gene related 36% (UTR and introns)

Interspersed repeats 44% (transposable elements)

Tandem repeats 18% (micro satellites)

Retrotransponsons

Mobile

Long interspersed elements (LINEs) and Short interspersed elements (SINEs)

Autonomous (code for all the proteins needed for copy and paste mechanism

Cause disease when in the middle of a gene because disrupt amino acid sequence and can encode early stop sign

Reverse transcriptase converts RNA into DNA

DNA inserted into DNA at a different loci by copy and paste mechanism

Retrotransposons transcribed into RNA

Yeast genome

Budding = 16 small chromosmes

Fission = 3 large

Chromosomes

DNA + chromatin

Heterochromatin = tightly packed, transcriptionally inert / Euchochromatin = loosely packed, transcriptionally active

Centromere = heterochromatin

Nucleosome = DNA and Histone

Beads on a string

Octamer of histones

Supercoiled

Cytogenetics

Microscopy

When chromosomes are condensed

Heterochromatin = dense = darker / Euchochromatin = less dense = lighter