Ricki Lewis

Halloween brings a cornucopia of candy body parts, so it’s a good time to review recent advances in organoid technology.

I’m missing a few body parts myself, so I have an interest in replacements that are biological: Mini-organs grown from stem cells. They’re even implanted with chips to record and send data, like this smart liver. Organoids more accurately model humans than do mice or monkeys, and can stand-in for experiments done on people. With that in mind, let’s take a look at some of the recent developments in this arena.

Mini-kidneys
Polycystic kidney disease affects about 12 million people, gumming up the intricate, highly symmetrically aligned tubules of the paired organs that filter 50 gallons of blood a day. Researchers from the Kidney Research Institute at the University of Washington describe their mini-kidneys, grown from human stem cells, in this issue of Nature.

To continue reading go to Genetic Literacy Project, where this article first appeared. Read More 

I’ve just discovered that my birthday, October 29, is also National Sea Slug Day, so I thought I’d look into these creatures about which I know nothing, alerted by a news release.

A new 74-page paper in the Zoological Journal of the Linnean Society offers numerous photos, sketches, and electron micrographs of the animals, a type of marine invertebrate also known as a nudibranch (“naked gills”).

In the past, invertebrate zoologists have sorted out the 3,000 or so species of sea slugs by color patterns; whether the gills are elevated, vibrating, or neither; and the shapes of the jaw and the radula, a tongue-like structure with tiny teeth. The new paper adds DNA sequencing to the list of classifying criteria, which added 17 new species to the known 57 or so. All 17 are members of the vibrantly-colored genus Hypselodoris.

To continue reading go to my blog DNA Science at Public Library of Science, where this post first appeared. Read More 

Preserving human microbiomes today, especially the more diverse ones from traditional peoples in developing nations, may provide treatments for diseases in the future, propose four microbiome experts in the October 5 issue of Science.

In the sci-fi classic The War of the Worlds, Martians attacking the Earth drop from the sky, dying, victims of bacterial infections to which humans have become immune. H.G. Wells wrote the novel from 1895 to 1897, set in Victorian England.

Then on October 30, 1938, a radio version aired in the US, with Orson Welles narrating so convincingly that many listeners panicked, thinking that Martians were truly invading. The first of five film adaptations debuted in 1953, set in California. Read More 

Spots are common in the animal kingdom. Birds, insects, reptiles, fishes, and of course mammals sport spots.

In Darwinian terms, a trait persists because it provides a benefit that leads to reproductive success – the essence of natural selection. The benefit isn’t always obvious to us. Two years ago DNA Science covered the case of an anteater’s scales – genome sequencing revealed that what looks to us like armor actually provides an immune response to skin infections.

Rudyard Kipling’s (1865-1936) Just-So Stories famously explained “how the leopard got its spots,” “how the camel got his hump,” and “how the rhinoceros got his skin.” The ideas of Kipling, a journalist, writer, poet, and novelist, seem superficially to echo those of Darwin and Lamarck in pondering evolutionary advantages of inheriting traits distinctive for a species, but diverge in attributing a purpose and goal to changes driven by natural selection. Biology doesn’t work that way.

Now joining the list of the leopard’s spots, camel’s hump, rhinoceros’ skin and pangolin’s scales is the giraffe’s markings. The new report, “Seeing spots: quantifying mother-offspring similarity and assessing fitness consequences of coat pattern traits in a wild population of giraffes,” published in the journal Peerj, uses image analysis and statistics to fashion “a new quantitative lexicon for describing spots.” It’ll remain to others to sequence more giraffe genomes to figure out whether the animal is of a single species with nine subspecies, or four species.

To continue reading go to DNA Science, my blog at Public Library of Science, where this post first appeared. Read More 

When a disease is as relentless as amyotrophic lateral sclerosis (ALS; aka Lou Gehrig’s disease; aka motor neuron disease), any promising research result is welcome news.
A study just published in Science Advances shows that two drugs already FDA-approved for other diseases, when teamed, halt neuron death and bolster muscle contraction in an “organ-on-a-chip” model of ALS. When the drugs meet in a device that places tiny balls of motor neurons from a patient next to strips of healthy skeletal muscle, the set-up not only recapitulates the disease, but shows the synergy of the drugs. They are rapamycin (Sirolimus) and bosutinib (Bosulif).

To continue reading go to DNA Science, my blog at Public Library of Science, where this post first appeared. Read More 

CRISPR-Cas9 gene editing quickly decimated two caged populations of malaria-bearing mosquitoes (Anopheles gambiae) in a recent study, introducing a new way to solve an age-old problem. But the paper describing the feat in Nature Biotechnology had a broader meaning regarding the value of basic research. It also prompts us to consider the risks and rewards of releasing such a powerful gene drive into the wild.

Instead of altering a gene affecting production of a reproductive hormone, the editing has a more fundamental target: a gene that determines sex. The work was done by Andrea Crisanti and colleagues at Imperial College London. Their clever use of the ancient insect mutation doublesex rang a bell for me — I’d used a fruit fly version in grad school.

To continue reading go to Genetic Literacy Project, where this post first appeared. Read More 

Many posts at DNA Science have been about families navigating life with a rare disease. I especially think of them during October, when so much attention is focused on breast cancer. One in eight women will develop breast cancer at some point in her life.

I know how important regular mammograms are – a scan late last year led to the surgery that likely saved my life. But I find my anxiety ratcheting up with the pervasive symbols and slogans, the pink apparel, labels, products, lit buildings, even garbage cans. Others in my thousands-strong closed breast cancer Facebook group are antsy too, although we don’t seem to be in the majority.

The pink October movement does a lot of good, in many ways. Still, I’ll skip the marches, for the reasons that others have posted on Facebook: I don’t need a reminder, I don’t want to be defined by an illness, and people are already aware of breast cancer. Instead here are a few other worthy causes that have awareness campaigns in October, not all of the conditions rare.

To continue reading go to DNA Science, my blog at Public Library of Science, where this post first appeared. Read More 

I hate the phrase “humans and animals” or derisively calling someone an animal. We’re not plants, fungi, bacteria, or protozoa, nor are we above other members of the animal kingdom, at least evolutionarily speaking. In recent weeks, with eclectic examples of prominent human males behaving badly dominating the news, I think of the wider biological lens.

Were the media moguls who forced parts of their anatomy into their female employees, the beloved TV star drugging and assaulting dozens of women, and the privileged schoolboys allegedly groping girls at long-ago parties just acting as biology dictates? Does the rush of power and/or the confusion of an alcoholic haze prevent some XYs from temporarily accessing the regions of their brains that might allow thinking to overcome the testosterone rush and halt their aggression, while dampening the hippocampus so that they later can convincingly claim to have no recall?

I don’t think so.

To continue reading go to DNA Science, my blog at Public Library of Science, where this post first appeared. Read More 

In the dystopian society of Nobel prizewinner Kazuo Ishiguro’s Never Let Me Go, cloned people are raised to provide organs for the wealthy.

So stark and terrifying is Ishiguro’s imagined world that I never thought I’d read something similar in a work of nonfiction, let alone in a top medical journal. But a Perspective in the September 6 New England Journal of Medicine (NEJM), "Voluntary Euthanasia – Implications for Organ Donation," eerily echoes some aspects of the 2005 novel (and forgettable 2010 film): choosing to donate one’s organs before death, minus the coercion and cloning.

To continue reading go to Genetic Literacy Project, where this post first appeared. Read More 

Many scientists trace their childhood inspiration to the towering skeletons of dinosaurs that still reign over the regal lobbies of the American Museum of Natural History, myself included. But “natural history” has a different meaning in medical research, especially in evaluating new treatments for rare diseases. Searching PubMed under “natural history study” turns up a curious 75,000 or so entries, including rare diseases and museum taxidermy.

A medical natural history study looks at how a disease unfolds over time, in real patients, to provide a point of comparison and variability for evaluating new treatments. A neurologist, for example, might know how to handle an otherwise healthy child with ADHD; a youngster with ADHD as part of Sanfilippo syndrome presents a different clinical picture. A natural history study provides an idea of what to expect.

To continue reading go to DNA Science, my blog at Public Library of Science, where this post first appeared. Read More