Recommended reads: a tale of human tails, heart reprogramming, pericytes, microglia

A piece on human tails and how we lost them caught my eye so I’ll start my weekly reads with that. This week I had the fewest Zoom meetings in ages, which allowed me to get more work done in my own lab and more reading. How about that? I even had some in-person meetings too. Some day maybe such feelings of a normal life in science will be the norm again and not the exception.

humans with tails, human tails
Do humans have tails? Not as adults, but we all have them as embryos. Figure 4.5. An extraordinary photo of a developing human embryo very early (7th week) during pregnancy that ended up outside the uterus, which makes pregnancy life-threatening to the mother. Image credit: Wikimedia open source image by Ed Uthman, M.D.vii The image has been modified to change it to black and white, and indications of specific structures including the brain and, yes, tail (recall that during development we humans do have tails for a while). From How to Build a Dragon or Die Trying, by Paul Knoepfler and Julie Knoepfler.

Human tails

How Humans Lost Their Tails, Carl Zimmer, NYT. This is a fun article and I highly recommend it.

In a sense we didn’t lose our tails completely because we still have them for a time when we are a fetus. At some point the tail cells (except what is left as the coccyx) must apoptose?

I actually read up on this in the last few years for the book my daughter Julie and I wrote about how to build a dragonOne idea was to play around with the features of the dragon’s tail.

Zimmer’s piece is based on a new preprint: The genetic basis of tail-loss evolution in humans and apes. This preprint focused on alterations in TBXT (Brachyury or T) as a proposed basis for how we lost our tails.

Many genes are important in tail development and probably in the loss of tails in adult humans. When I was a postdoc, some of the Myc/MycN knockout mice that I produced had unusual tails. These included short or kinked tails.

Note that in extremely rare cases humans can be born with tails.

More reading: papers and media

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