HMB265H1 Lecture Notes - Lecture 18: Zygote, Del2, Fusion Protein

• School: UTSG
• Department: Human Biology
• Course: HMB265H1
• Professor: Maria Papaconstantinou

Document Summary

Chromosomal rearrangements: consequence of, chromosomal breakage, aberrant recombination. Chromosome breakage and subsequent dna repair can result in all classes of chromosomal rearrangements. Aberrant crossing-over at repeated sequences can also produce rearrangements. The chromosomes in (d) are nonhomologous: with dna breaks and incorrect repair, we can have four different types of chromosomal rearrangements, deletions two breaks, lost genetic material. Inversions break, 180 inversion, then repair: deletion or duplication break in sister chromatids, translocation nonhomologous chromosomes exchange material. The green arrows represent the repeated sequences and indicate their relative orientations. The repeated dna sequences may be simple sequence repeats (ssrs) or transposable elements. The chromosomes in (c) could be homologues or sister chromatids. Intragenic deletion: small deletion within gene: del (df) homozygotes usually viable, gene imbalance in del heterozygotes, may result in haploinsufficiency, deletions can occur within a gene or can span many genes.