Biology subjects

Kapuralin, K.

Publications and source records attributed to Kapuralin, K..

2 recordsLinked to original sources

bioRxiv2024

Morphological and functional convergence of visual projections neurons from diverse neurogenic origins in Drosophila

The Drosophila visual system is a powerful model to study the development of neural circuits. Projection neurons that relay visual information from the lobula part of the optic lobe to the central brain (the lobula columnar neurons-LCNs), are thought to encode different visual features relevant to natural behavior. There are [~]20 classes of LCNs whose projections form highly specific, non-overlapping synaptic domains in the brain called optic glomeruli. Although functional investigations of several LCN circuits have been carried out, very little is known about their developmental origin and the stem cell lineages that generate the LCN subtypes. To address their origin, we used single-cell mRNA sequencing to define the transcriptome of each LCN subtype and identified driver lines that are expressed in specific LCNs throughout development. We show that LCNs originate from neural stem cells in four distinct regions in the fly brain that exhibit different modes of neurogenesis, including the ventral and dorsal tips of the outer proliferation center (tOPC), the ventral tips of the inner proliferation center (vtIPC) and the central brain (CB). This convergence of similar neurons illustrates the complexity of generating neuronal diversity in the brain and likely reflects the evolutionary origin of each LCN subtype that detects a highly specific visual feature and influence behaviors that might be specific to each species.

neuroscience↗

bioRxiv2018

Phenotypic convergence in the brain: distinct transcription factors regulate common terminal neuronal characters

Transcription factors regulate the molecular, morphological, and physiological characters of neurons and generate their impressive cell type diversity. To gain insight into general principles that govern how transcription factors regulate cell type diversity, we used large-scale single-cell mRNA sequencing to characterize the extensive cellular diversity in the Drosophila optic lobes. We sequenced 55,000 single optic lobe neurons and glia and assigned them to 52 clusters of transcriptionally distinct single cells. We validated the clustering and annotated many of the clusters using RNA sequencing of characterized FACS-sorted single cell types, as well as marker genes specific to given clusters. To identify transcription factors responsible for inducing specific terminal differentiation features, we used machine-learning to generate a random forest model. The predictive power of the model was confirmed by showing that two transcription factors expressed specifically in cholinergic (apterous) and glutamatergic (traffic-jam) neurons are necessary for the expression of ChAT and VGlut in many, but not all, cholinergic or glutamatergic neurons, respectively. We used a transcriptome-wide approach to show that the same terminal characters, including but not restricted to neurotransmitter identity, can be regulated by different transcription factors in different cell types, arguing for extensive phenotypic convergence. Our data provide a deep understanding of the developmental and functional specification of a complex brain structure.

developmental biology↗