# Global investigation of cell trajectory and lineage relationships in the vertebrate brain with single-cell transcriptomics

> **NIH NIH K99** · HARVARD UNIVERSITY · 2020 · $128,574

## Abstract

PROJECT SUMMARY/ABSTRACT
A key goal in developmental biology is to understand how the brain is specified and organized regionally,
cellularly and molecularly. Central to this vision is determining the origins and fates of cells during development,
and thus map the progressive steps of cell specification and lineage divergences. Focused efforts have provided
insight into specific cell types and lineages, however global views of these processes have been lacking. Recent
technological breakthroughs in single-cell transcriptomics and lineage tracing using CRISPR-Cas9 tools are now
enabling the realization of this vision. The long-term goal of this project is to obtain global views of cellular
relationships and molecular changes during neural development and cell type diversification in the vertebrate
brain. These include generating large-scale, single-cell resolution cell specification trajectories that describe
molecular cascades underlying cell fate specification (Aim 1), and lineage trees that describe the history of cell
divisions (Aim 2). These trees represent many key aspects of developmental decisions and can be used to
determine gene expression cascades during cell specification and regulatory factors involved in progenitor
priming and neuron identity (Aim 1). Furthermore, they can address how often transcriptional and lineage
identities are related (Aim 2). These studies will generate resources for genome-wide and single-cell analysis of
brain development and reveal cellular and molecular mechanisms for generating neuronal cell diversity.
My career goal is to run an academic lab aimed at investigating cellular and molecular features underlying brain
development, neurogenesis and neural stem cell activity using global and focused approaches. The proposed
research draws on my previous experience with characterizing gene regulatory networks in neurogenesis and
extends it to a new model organism, zebrafish, while exposing me to new experimental and analytical methods.
I have developed a detailed training plan with my co-mentors, Drs. Len Zon, Alex Schier, and Josh Sanes, who
have combined expertise in development, behavior, neurobiology, single-cell analysis and disease modeling. To
help me transition to independence, we will meet regularly to discuss research progress, brainstorm ideas, and
obtain guidance on grant writing, mentorship and lab management. My K99 advisory committee consists of Drs.
Allon Klein, Sean Megason and Gord Fishell, whose collective expertise in single-cell genomics, zebrafish
development, and neurobiology will provide me with technical and conceptual feedback in executing my research
plan. I will continue to mentor a research technician/graduate student, will present my research at two meetings
per year, take courses on bioinformatic analysis, mathematical modeling and grant writing, and attend seminars
to broaden my scientific training. As a member of the Harvard Department of Molecular and Cellular Biology, I
will hav...

## Key facts

- **NIH application ID:** 10021448
- **Project number:** 5K99HD098298-02
- **Recipient organization:** HARVARD UNIVERSITY
- **Principal Investigator:** Bushra Raj
- **Activity code:** K99 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $128,574
- **Award type:** 5
- **Project period:** 2019-09-19 → 2021-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10021448

## Citation

> US National Institutes of Health, RePORTER application 10021448, Global investigation of cell trajectory and lineage relationships in the vertebrate brain with single-cell transcriptomics (5K99HD098298-02). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10021448. Licensed CC0.

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