Possible lineages for Q lineage specification defects.

A) The wild-type Q lineage. B) A Q.a division defect where the Q.aa fails to die and adopts the Q.ap fate as an A/PQR neuron. C) A Q.p division defect where the Q.pp fails to die and adopts the Q.pa fate. D) A Q.p division defect where the Q.pp fails to die but does not divide and adopts an SDQR/L or A/PVM fate. E) A Q division defect where Q.p adopts the fate of Q.a. This results in an extra A/PQR and an absence of the Q.p descendants. F) A Q division defect, where the Q.a adopts the fate of Q.p. This results in a duplication of the SDQR/L and A/PVM neurons and an absence of the A/PQR. The Q.p transformation in E and the Q.a transformation in F may also display the defects shown in B, and C and D respectively, resulting in three or more neurons that express a specific fate.

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