the basics lecture Flashcards
Normal diploid cell karyotype
what is a Human idiogram?
old fashioned method of visualizing chromosomes
what is G-banding?
Giemsa stain –binds to phosphate groups in DNA
dark bands = gene poor AT-rich regions
light bands = gene rich GC-rich regions
what is going on?
Aneuploid – incorrect number of chromosomes
Triploid chromosome 8 and 13
Male
what are the arms of the chromosome called?
short arm is p for petite
long arm is q, as q is after p in the alphabet
what are the healthy positions of centromeres?
healthy if it is where it should be for the specific chromosome
what is FSH?
fluorescence in situ hybridisation
whats going on in this FSH image?
Is the restriction points = centromere
Green is a specific FISH probes
Two spots sitting together = pair of sister chromatids
Two sets of spots = two pairs = homologous chromosomes
whats going on?
Yellow probe is a single probe = why all other, targeting repetitive element of DNA. Can see where they are in the genome
what is chromosome painting?
Using different fluorescent probes to make different colour
what is mbanding?
High resolution multicolour banding
what is it and why is it good?
Computational analysis
Much more accurate and higher through put
46, XY, der(1)t(1;5)(p21;p12), -5, +11der (11)t(1;5;11)(p32.2;q12;p12)X2, del(12)(p11.2),der(14)t(1;5;12;14)(p21;q35.1;p12;q24), der(17)t(11;17)(p14;p11.2)
whats going on?
Male ?
Complex rearrangement = normal for cancer presence
46 chromosome = normal. But clearly not normal 46!
Der – derivitative on 1. translocation between 5.
Translocations and whole chromosome losses
whats this showing?
mBANDing of abnormal Chromosome 5
Damaged G1 lymphocytes
Arrows = Alu breakpoints
