The Nanopore Minion is still a thing, but it's sequencing and has higher error rates than competing short-read methods like Illumina's sequence by synthesis.
"23andMe uses genotyping, not sequencing, to analyze your DNA. Sequencing technology has not yet progressed to the point where it is feasible to sequence an entire person’s genome quickly and cheaply enough to keep costs down for consumers. It took the Human Genome Project, a consortium of multiple research labs, over 10 years to sequence the whole genomes of just a few individuals."
I wasn't aware of the variability in thymic involution. I guess most studies focus on averages. If you have links to more information about these outliers I'd be very interested in reading up on them.
The most recent literature that I'm seeing is showing the most pronounced time of thymus involution occurring around puberty, suggesting a programmed switch from a growing to reproductive phase of life.
"Regardless of the seemingly crucial role of the thymus in preserving homeostasis, its involution in humans and other mammals begins in childhood and peaks around puberty, resulting in an almost completely non-functional organ in aging."
https://www.sciencedirect.com/science/article/pii/S156816372...
In this light the following makes sense (stopping or suppressing the switch to a reproductive life).
"Castrating rodents before puberty or reducing the levels of sex hormones [e.g., by using Lupron, which desensitizes the luteinizing hormone-releasing hormone (LHRH) receptors] can attenuate or markedly recover the involution process in aging mice."
Those are interesting cases. A similar but more ubiquitous strangeness is somatic mosaicism, specifically in the brain where it seems that "no two neurons are genetically alike."
I was in line for the Terminator ride at Universal Studios when I stumbled onto this article a few years back. Couldn't stop thinking about it the rest of the trip.
https://www.scientificamerican.com/article/scientists-surpri...
“The idea is something that 10 years ago would have been science fiction,” says biochemist James Eberwine of the University of Pennsylvania. “We were taught that every cell has the same DNA, but that’s not true.”
Edit:
Reading into this more again for the first time in a while. I'm amazed at how large some of these differences are. Many having 1 million base pair copy number variants.
"Single cell sequencing of endogenous human frontal cortex neurons revealed that 13%-41% of neurons have at least one megabase-scale de novo CNV, that deletions are twice as common as duplications, and that a subset of neurons have highly aberrant genomes marked by multiple alterations."
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3975283/
Couple this with...
"Megabase-scale copy number variants (CNVs) can have profound phenotypic consequences. Germline CNVs of this magnitude are associated with disease and experience negative selection. However, it is unknown whether organismal function requires that every cell maintain a balanced genome. It is possible that large somatic CNVs are tolerated or even positively selected."
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4772019/
I can't imagine our brains are just accumulating mutations of this size for no reason.
Age is probably the biggest influence on a "healthy" immune system. I haven't kept up with recent research, but if memory serves the immune repertoire (diversity of T and B cell receptors) decreases essentially linearly with age.
I'm hopeful that cancer and immune profiling will be able to be used in tandem to (1) identify cancer early and (2) identify gaps in the immune repertoire to facilitate (3) design of antibodies that specifically target the cancer.
I'm surprised as well. I thought the problem with cancer is that the immune system doesn't react/detect it and therefore might not provide a discernible signal.
Microsoft Research was a partner in the joint collaboration. Pretty sure this was the research that culminated in the T-Detect Lyme product that Adaptive Biotech launched last year (definitely some Adaptive representation in the publication).
It’s what you think it is, and it happens to more than just mice. I toured a bioengineering lab where they were actively severing the spines of chimpanzees to perform fiber rerouting experiments. I think the normal citizen never thinks much if at all about this kind of thing because they’re never exposed to it. A few researchers have opened up to me personally about their personal psychological trauma caused by involvement with animal experimentation. A couple PhD candidates I know changed fields entirely. One to ecology and another to environmental engineering. I personally moved forward with bioinformatics.
Edit: that isn’t to say that this result isn’t exciting for human welfare. We’ll see if it translates…
https://nanoporetech.com/products/sequence/minion
Sequencing DNA with nanopores: Troubles and biases https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8486125/
Based on what I'm seeing from 23andMe's website they only do genotyping, not sequencing.
https://customercare.23andme.com/hc/en-us/articles/227968028...
"23andMe uses genotyping, not sequencing, to analyze your DNA. Sequencing technology has not yet progressed to the point where it is feasible to sequence an entire person’s genome quickly and cheaply enough to keep costs down for consumers. It took the Human Genome Project, a consortium of multiple research labs, over 10 years to sequence the whole genomes of just a few individuals."
Edit: https://www.23andme.com/total-health
I guess they started providing whole exome sequencing, but I can't find information about what depth they're doing it at.