Arlotta et al., 2005.
Ctip2 = Bcl11b
Otx1, TF in layers V and VI
Er81, TF in layer V, multiple neuronal subtypes
CsMNs = upper motor neurons
CPNs, CtPNs, and CsMNs were purified at four time points: early postmitotic (E18), more differentiated (P3, P6), and more mature and connected (P14).
FACS achieved >99% purity.
P14 CsMNs were so fragile that they were fixed in RNAlater following dissociation, and then were purified.
CsMN genes included transcription activators and repressors; zinc finger domain-containing proteins; cell surface proteins and receptors; calcium signaling molecules; genes involved in neuronal specification, cell adhesion, and axon guidance; and genes involved in critical signaling cascades.
In layer V, Lmo4 is found in CPNs but not in CsMNs, and Ctip2 is found in CsMNs but not in CPNs.
Ctip2 is expressed at high levels in CSMN and corticotectal neurons, but not callosal neurons. It is expressed at a much lower level in corticothalamic neurons and GABAergic neurons.
How are biological replicates different from hybridization replicates?
How does hiearchical clustering work?
What is the SAM method?
What is an EST?
EST = expressed sequence tag
This paper showed for the first time that there were genetically distinct neuronal subtypes within the same layer. They distinguished markers that were not merely layer-specific, but also subtype-specific.
They aimed to define the combinatorial program of novel genetic determinants of the CSMN population.