Article Figures & Data
Figures
- Figure 1.
Chromosome 21 gain and loss is observed in cells isolated from the normal human brain. Human lymphocyte labeling demonstrates the specificity of the paint and point probes in metaphase spreads (A) and interphase nuclei (B). Neural progenitor cells from a Down's syndrome fetus have three copies of chromosome 21, as seen in a metaphase chromosome spread (C) and in an interphase nucleus (D), demonstrating the sensitivity of the FISH probes with regard to detecting numerical abnormalities of chromosome 21. E-H, Nuclei isolated from the brains of different patients containing one (E), two (F), three (G), or four (H) copies of chromosome 21. Blue indicates 4′,6-diamidino-2-phenylindole, whole-chromosome paint is shown in green, and the chromosome 21 point probe is shown in red. There is complete overlap between the paint and the point probe, as seen at higher magnification in the insets. Arrowheads indicate the numbers of chromosome 21 per cell. Scale bar, 5 μm.
- Figure 2.
NeuN immunolabeling and cell sorting. A, Isolated normal human brain nuclei populations (P1) were gated based on forward scatter and side scatter and gated into NeuN+ (P4) and NeuN- (P5) sort populations based on Alexa Fluor 488 signal. The NeuN+ population is generally composed of larger nuclei than NeuN- nuclei based on forward scatter, although there is a significant size overlap. B, A representative preparation of sorted nuclei demonstrating >99.5% purity of separation between NeuN+ (P4) and NeuN- (P5) populations.
Tables
- Table 1.
Percentages of whole chromosome 21 gain and loss in the brain vary within and among individuals
Aneuploid karyotype Age (years) Cell type % Disomy % Tetrasomy % Monosomy % Trisomy % Aneuploidy Mean chromosome number 2 Frontal cortex cells 94.3 2.5 1.7 1.5 3.2 2.05 15 Occipital cortex cells 93.8 2.4 2.2 1.6 3.8 2.04 35 Frontal cortex cells 93.9 2.4 1.8 1.8 3.6 2.05 48 Frontal cortex cells 93.8 2.6 1.6 2.0 3.6 2.06 77 Hippocampal cells 91.5 3.8 2.6 2.3 4.8 2.07 86 Hippocampal cells 92.4 2.4 3.0 2.2 5.2 2.04 Average Brain cells 93.3 2.7 2.1 1.9 4.0 2.05 33 Lymphocytes 99.8 0.2 0.4 0.2 0.6 2.00 <0 Down's syndrome neural cells 7.1 3.6 0 89.3 89.3 2.96 -
Lymphocytes and Down's syndrome cells were used to validate the counting criteria using chromosome 21 FISH probes.
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- Table 2.
Percentages of whole chromosome 21 gain and loss in neurons and non-neuronal cells isolated from the brains of three different individuals and sorted by FACS
Aneuploid karyotype Age (years) Cell type % Disomy % Tetrasomy % Monosomy % Trisomy % Aneuploidy Mean chromosome number 2 Neurons 95.4 1.2 2.0 1.4 3.4 2.02 2 Non-neuronal cells 95.8 0.9 2.5 0.8 3.3 2.00 35 Neurons 96.4 0.8 1.8 1.0 2.8 2.01 35 Non-neuronal cells 95.0 1.6 2.5 0.9 3.4 2.02 48 Neurons 96.5 1.3 1.5 0.8 2.3 2.02 48 Non-neuronal cells 94.7 1.4 3.1 0.8 3.9 2.01 Average Neurons 96.1 1.1 1.8 1.1 2.8 2.0 Average Non-neuronal cells 95.2 1.3 2.7 0.8 3.5 2.0
