I have returned, but all this post will be is a random smattering of thoughts and excuses because that’s better than continuing to not update.
I have 4 drafts of half-written posts in which I try to tackle major topics or points of confusion, but (obviously) I haven’t posted any of them, even the ones I first started more than six months ago.
My most recent half-finished draft was abandoned when I realized 2 paragraphs in that it could easily be a book. The topic I was trying to address was human tissue use in research. I thought I could make a quick list of the major ethical concerns, another list of what types of human tissue are used in biology research, and then define each of those and address common misconceptions or at least explain the good, the bad, and the ugly and talk about what are historical versus modern practices. Why I thought that would all fit in a short blog post, I don’t know.
But I can tell you the inspiration for that post:
I made a mistake in my last post: the human cells I’m working with are not induced-puripotent stem cells (i.e. cells taken from adult, often skin cells from a cheek swab and reprogrammed into stem cells that are incapable of forming a human embryo but can still be differentiated into every cell type and used to study human cells), but they are actually an embryonic stem cell line. The specific line was made from WA09, a line created at the University of Wisconsin in 2001. Embryonic stem cell lines do actually come from embryos, but like the induced-pluripotent stem cells, we are not capable of making a human embryo from them. This particular line came from a medical center in Israel. The source of the tissue for embryonic stem cells is leftover tissue from IVF. When doing IVF, many more eggs are fertilized than will be needed to ensure there will be enough. Cells are taken from leftover blastocysts* a few days later.
*the first few paragraphs of that Wikipedia page will probably explain this better, but basically a blastocyst is a ball of cells that is the very early embryo.
Embryonic stem cells have some big advantages in that they are much more normal and mimic normal development much better than induced-pluripotent stem cells, making them far better for basic research applications. There certainly is more contention around their use, but I think it’s worth remembering that this tissue was taken from an abortion that would have been done anyway (I have never heard of a modern case of an abortion being done specifically to obtain cells, and if there is one, you’d be hard-pressed to find scientists who don’t agree that would be wildly unethical), and this single cell line has been around for 15 years and has been and will continue to give us a valuable model that has the advantage of 1) being human cells** and 2) not requiring sacrificing the comfort or lives of any people or animals to use.
**mice are really great for a lot of research, but they are not humans. This is one reason we’ve cured cancer in mice 100 different ways, but still struggle with treating it in people.
So what I’ve been up to the past few months is a lot of getting set up to grow and use the cells myself and continuing to work on both the photoreceptor project and my optogenetic project.
And to end the post, here’s a pretty picture of my photoreceptors! The green marks the photoreceptors and the purple binds the cytoskeleton (cyto=cell, skeleton; basically the structure that gives the cell its shape).
Note on edits: My original post mistakenly said that embryonic stem cells could come from abortions, which is entirely wrong. I think I’ve absorbed too much mainstream media and didn’t think critically enough about it. Fortunately another grad student corrected me, and once he said this it was really obvious why embryonic stem cells can’t possibly come from abortions: the cells need to be taken from a very, very early stage: a few days after fertilization and before implantation. Abortions happen weeks later and so they would never be a source of a cell line. All embryonic stem cell lines originally come from unused embryos from IVF (which would otherwise get frozen for later use, donated to another family for implantation, or destroyed). Sorry for spreading misinformation!