I remember the first time I ever witnessed human cell division first hand and it was really excitement. I was working as a part-time tech in the Lane Lab at UC San Diego School of Medicine. We studied heart disease and grew human umbilical cord endothelial cell cultures. It was striking to see a plate of cells double in numbers over the course of days and then do it again. Sometimes we’d be able to see cells right in mitosis.
Overall, I was hooked on cell biology.
So a report of a new kind of cell division caught my attention recently. I’ll start with that paper.
Skin cells undergo asynthetic fission to expand body surfaces in zebrafish, Nature. This one is a surprise. The idea is that as fish grow the skin needs to massively expand so fish cells sometimes divide without replicating their DNA. In a way this could make sense and could be unique to skin. The last stages of epidermal differentiation yield squames, which are dead “tiles” of the skin’s outer layer. They are dead cells lacking DNA. What do you think of the idea that what was reported in that Nature pub is an entirely new kind of cell division?
Vertex Perplexed by FDA Hold on Cell Therapy for Type 1 Diabetes, BioSpace. The piece reports the hold but the reason for it isn’t clear. Several other media covered this development and the FDA’s reason was generally that there was “insufficient evidence to support increasing dosage.” Not sure what that really means. In other recent Vertex news coming well before the FDA decision, Doug Melton left Harvard to be in a leadership role at Vertex related to the cell therapy for diabetes group there.
The gene-edited pig heart given to a dying patient was infected with a pig virus, MIT Tech Review.
Cilia-free stem cells could open a new way to study rare diseases, Drug Target Review.
3D-organoid culture supports differentiation of human CAR+iPSCs into highly functional CAR T cells, Cell Stem Cell.