Metaphase FisH: detection of deletion at 22q13 4 Red =juxta-centromeric bacterial artificial chromosome( BAC) DNA probe Green telomeric BAc dNa probe lying with deletion region Chromosome were counter-stained with DAPl
Metaphase FISH: detection of deletion at 22q13 Red = juxta-centromeric bacterial artificial chromosome (BAC) DNA probe Green = telomeric BAC DNA probe lying with deletion region Chromosome were counter-stained with DAPI
Interphase FISH: detection of chromosomal duplication and deletion on chromosome 17p12 (a)Duplication of the region spanning PMP22 (red) in an individual with Charcot-Marie-Tooth disease type 1A (CMT1A (b)Deletion of the same region in an individual with hereditary neuropathy with liability to pressure palsies( HNPP) The region adjacent to the rearrangement is stained using a probe for FL/1(green Source: Osborne L. Nature Genetics 40 6-7. 2008
Interphase FISH: detection of chromosomal duplication and deletion on chromosome 17p12 (a) Duplication of the region spanning PMP22 (red) in an individual with Charcot-Marie-Tooth disease type 1A (CMT1A). (b) Deletion of the same region in an individual with hereditary neuropathy with liability to pressure palsies (HNPP). The region adjacent to the rearrangement is stained using a probe for FLI1 (green). Source: Osborne L, Nature Genetics 40, 6-7, 2008
Array comparative genomic hybridization(CGH)for detecting copy number variants(CNVs) chromosomal microdeletions and duplications Patients DNA Control dNA Hybridise Scan Results
Array comparative genomic hybridization (CGH) for detecting copy number variants (CNVs) [chromosomal microdeletions and duplications]
B. The origin of chromosome abnormalities Gametogenesis and meiosis(review) Chromosome recombination Chromosome seg elation Chromosome abnormalities in somatic cells (cancer) The molecular structure of chromatin DNA methylation and histone methylation and acetylation X-chromosome inactivation Imprinting Telomeres
B. The origin of chromosome abnormalities • Gametogenesis and meiosis (review) • Chromosome recombination • Chromosome segregation • Chromosome abnormalities in somatic cells (cancer) • The molecular structure of chromatin • DNA methylation and histone methylation and acetylation • X-chromosome inactivation • Imprinting • Telomeres
Gametogenesis and meiosis Meiosis I Meiosis Il (a) Gamete formation in the male Spermatids Sperm cells Meiosis 1& l occur post-puperty Egg cell haploid (b) Gamete formation in the female Meiosis I begins during embryonic weeks 16-24 Meiosis ll occurs during menstrual cycles post-puperty (halts at diplotene stage
Gametogenesis and meiosis Meiosis I begins during embryonic weeks 16-24 (halts at diplotene stage) Meiosis II occurs during menstrual cycles post-puperty Meiosis I & II occur post-puperty