Researchers at the National Institutes of Health (NIH) have unveiled an atlas detailing the gene expression programs activated during the first five days of zebrafish development. This crucial period witnesses the transformation of single cells into diverse cell types that eventually form tissues and organs in juvenile fish. The study, published in Developmental Cell, provides a comprehensive overview of the gene expression patterns within nearly every cell type during this developmental phase, offering insights into the genetic orchestration of embryonic growth.
Zebrafish, despite their small size, are valuable models for studying human development and disease. The genetic programs directing embryonic growth are often similar across different species, making zebrafish a useful tool for understanding human biology. Their transparency, external fertilization of eggs, and genetic tractability make them particularly suitable for studying various aspects of development.
To create the atlas, the research team employed single-cell RNA sequencing, a powerful technique that allows the identification of gene expression programs within individual cells. Samples were collected every two to 12 hours over the course of five days, tracking nearly 490,000 cells continuously during zebrafish development. On average, each cell had 8,621 transcripts and 1,745 genes detected. The resulting atlas covers 62 developmental stages and provides insights into the molecular processes guiding the differentiation of various cell types.
The researchers highlighted the atlas’s utility by focusing on the development of understudied cells, specifically BEST4+ cells in the intestine. These cells are associated with gastrointestinal diseases and cancer in humans. Since BEST4+ cells are absent in other common model organisms, such as mice, little is known about their development.
Using the atlas, the team computationally predicted the full developmental program of BEST4+ cells, identifying the signals initiating their development and the transcription factors executing the process. This information can be further evaluated in model organisms or clinical samples to enhance the understanding of BEST4+ cells’ role in human disease.
Dr. Jeffrey A. Farrell, the senior author of the study and head of NICHD’s Unit on Cell Specification and Differentiation, emphasized the atlas’s significance as a thorough resource describing the expression programs of hundreds of cell types across various developmental stages. The study revealed insights into several understudied cell types, including those involved in human diseases, such as intestinal cells, smooth muscle surrounding the intestine, and cells surrounding blood vessels.
The atlas, an open-source resource, serves as a valuable tool for the research community, providing a foundation for further investigations into zebrafish development. By uncovering the genetic and molecular intricacies of embryonic growth, this atlas contributes to our understanding of fundamental biological processes and offers potential applications for studying human development and diseases.
In conclusion, the NIH-led research has produced a comprehensive atlas of zebrafish development, shedding light on the gene expression programs driving the transformation of single cells into diverse cell types. This resource has the potential to advance our understanding of embryonic growth, with implications for studying human development and diseases.
News Reference
National Institute of Health, https://www.nih.gov/news-events/news-releases/nih-researchers-create-genetic-atlas-detailing-early-stages-zebrafish-development.
