How circuits assemble starting from stem cells is a fundamental question in developmental neurobiology. Dynamic gene expression in stem cells contribute to molecular diversity of neuronal progeny. Morphology and synaptic connections of neurons are important for circuit organization and function. However, less clear is the relationship between molecular diversity and the specification of neuronal morphology and synaptic partnerships. Here, I tested the hypothesis that dynamic gene expression in neural stem cells is a general strategy underlying neuronal integration into circuits. To do so, I used the Drosophila larval motor system. This system offers unparalleled resolution of neural stem cells as well as neurons at single-cell and -synapse resolution. The Heckscher lab discovered that neuronal birth time and circuit membership are correlated (Wreden et al., 2017). This finding implies that time-linked information plays an instructive role for circuit membership. At the time of birth, neurons receive information from two sources: intrinsic –inherited from their stem cell parent and extrinsic –cues from their environment. As development progresses, intrinsic and extrinsic cues change simultaneously. To uncouple intrinsic cues from developmental time in stem cells, I specifically manipulated dynamically-expressed transcription factors called temporal factors. Temporal factors act in Drosophila stem cells (neuroblasts), to specify embryonic molecular marker expression in neuronal progeny. Using genetic approaches, I altered the temporal dynamics of transcription factor expression in a neuroblast lineage-specific manner. Then, I performed neuromuscular dissections, single-cell tracing, labeling with marker genes, confocal imaging, electrophysiology (in collaboration), and calcium imaging to examine motor neuron morphology and synaptic connectivity (Meng et al., 2019; 2020). I found that temporal transcription factors acting in neuroblast are potent regulators of functional motor neuron-to-muscle synaptic partnerships, but that the local local synaptic environment can also influence synaptic partnerships. Further, my data revealed that molecular markers used to assess embryonic neuronal fate do not faithfully correlate with motor neuron to muscle synaptic partnerships. Altogether, my data demonstrates that intrinsic information strongly influences circuit assembly decisions. Next, since the environment greatly differs in the bodywall muscle periphery vs the CNS I characterized the dendrite morphology of single motor neurons and interneurons within the larval CNS. Here, I found evidence that intrinsic information strongly influences motor neuron dendrite morphology (Meng et al., 2019), but may have less of an impact on interneuron dendrite morphologies (unpublished, work in progress). This suggests, there are likely differences in strategies underlying synaptic partnership decisions in the periphery versus the CNS. To understand these differences, future research will need to obtain single-synapse resolution of synaptic partnerships formed within the CNS. To further elucidate intrinsic molecular programs specifying motor neuron to muscle synaptic partnership decisions, I manipulated other intrinsic, early acting factors (e.g. Notch, Hb9, and Eve). These unpublished experiments further support the hypothesis that inherited information from neural stem cell parents is likely a general strategy underlying neuronal integration into circuits. More broadly, strategies underlying motor circuit assembly identified in the Drosophila larval system are likely repeated throughout the Animal Kingdom where motor circuits are essential for locomotion.