Neural crest-derived melanoblasts are the progenitors of melanocytes, the pigment cells of the skin, hair and choroid. Previous studies of adult chimaeric mice carrying different coat colour markers have suggested that the total melanocyte population is derived from a small number of melanoblast progenitors, each of which generates a discrete unilateral transverse band of colour. This work also suggested minimal mixing of cells between clones. We have used two complementary approaches to assess the behaviour of migrating clones of melanoblasts directly in the developing embryo. First, we made aggregation chimaeras between transgenic Dct-lacZ and non-transgenic embryos, in which lacZ is a marker for melanoblasts. Second, we generated transgenic mice carrying a modified lacZ reporter construct containing a 289 base pair duplication (laacZ) under the control of the Dct promoter. The laacZ transgene is normally inactive, but reverts to wild-type lacZ at low frequency, labelling a cell and all of its progeny at random. Mosaic embryos containing labelled melanoblast clones were generated. In contrast to previous data, chimaeric and mosaic embryonic melanoblast patterns suggest that: (1) there is a large number of melanoblast progenitors; (2) there is a pool of melanoblasts in the cervical region; (3) different cell dispersion mechanisms may operate in the head and trunk regions; and (4) there is extensive axial mixing between clones.
The Company of Biologists Workshops
For the last 15 years, our publisher, The Company of Biologists, has provided an apt environment to inspire biology and support biologists through our Workshops series. Read about the evolution of the Workshop series and revisit JEB's experience with hosting the first Global South Workshop.
Call for papers – Lifelong Development: the Maintenance, Regeneration and Plasticity of Tissues
Development invites you to submit your latest research to our upcoming special issue – Lifelong Development: the Maintenance, Regeneration and Plasticity of Tissues. This issue will be coordinated by Guest Editors Meritxell Huch (Max Planck Institute of Molecular Cell Biology and Genetics, Germany) and Mansi Srivastava (Harvard University and Museum of Comparative Zoology, USA), working alongside our team of academic Editors. Submit your articles by 30 May 2025.
Meet our 2025 Pathway to Independence (PI) fellows
We are delighted to announce our third cohort of PI fellows - researchers whom we will be supporting as they transition from postdoc to Principal Investigator. Read about the eight talented fellows chosen, whom we're excited to be working with as they navigate the job market.
A case for broadening our view of mechanism in developmental biology
In this Perspective, B. Duygu Özpolat and colleagues survey researchers on their views on what it takes to infer mechanism in developmental biology. They examine what factors shape our idea of what we mean by ‘mechanism’ and suggest a path forward that embraces a broad outlook on the diversity of studies that advance knowledge in our field.
the Node: Have your say
Our community site, the Node, is conducting a user survey about the content and the design of the site. Help us shape the Node's future and thank you for being a part of the Node over the last 15 years.
Social media
