Biology 2581B Chapter Notes - Chapter All: Methyltransferase, Histone H2A, Histone H2B
24 Apr 2016
School
Department
Course
Professor
Document Summary
Syntenic segments: identity, order, and transcriptional direction are almost the same/conserved within the two chromosomes. Mouse and human genome evolved and reshaped their chromosomes through approximately. 300 events: differences cannot be seen through karyotyping, but can be seen by comparing dna sequences. Deletions: large =identifiable by karyotyping; small = must analyze gene (e. g. pcr). Homozygotes or heterozygotes for deletions are usually lethal: e. g. of exception: heterozygous deletion for short arm of chromosome 5 = cri du chat, heterozygosity will change gene dosage (genetic imbalance) Sometimes, heterozygous gene dosage of one gene is okay, but with more than one gene it"ll be lethal: if human genome is >3% deleted, it will be lethal. Also, a gene that"s only present in one copy (heterozygous deletion) will be more vulnerable to mutations. No recombination can occur in the deletion loop of the normal chromosome, so del/+ heterozygotes will always inherit the dna in the deletion loop as a unit.
