12th edition of my human genetics textbook


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Glenn Nichols, surrounded by his hospice team. The author is in yellow.

Genetic Linkage

Why We May Need a ‘Noah’s Ark’ of Microbes to Protect Our Health in the Future

October 27, 2018

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. (more…)

How the Giraffe Got Its Spots: A Genetic Just-So Story

October 23, 2018

Tags: giraffe

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.

Drug Duo Treats ALS – On A Chip

October 23, 2018

Tags: ALS

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.

Mosquito massacre: Can we safely tackle malaria with a CRISPR gene drive?

October 9, 2018

Tags: mosquito, malaria, CRISPR, gene editing

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.

October Isn’t Just for Breast Cancer Awareness

October 9, 2018

Tags: breast cancer

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.

Men Behaving Badly: A Lesson from Duck Sex?

October 1, 2018

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.

instruction
Project to engage students in helping families with rare genetic diseases
Book Club Reader's Guide
Many challenging questions to stimulate thought and discussion.
Instructor's Guide
38 discussion questions to get students thinking and talking about gene therapy, including the science, ethical issues, and the drug approval process.
Narrative science
The Forever Fix is the uplifting true story of 8-year-old Corey Haas, who was cured of hereditary blindness just 4 days after gene therapy.
College Textbooks
A spectacularly-illustrated, clearly written human anatomy and physiology textbook, used in pre-health profession programs throughout the U.S.
A highly engaging, clearly written, beautifully illustrated introduction to the science of human genetics for the non-scientist. Now in its 11th edition, 12th to be published in September 2018.
Nonfiction
An ideal starting point for anyone who wants to know more about genes, DNA, genomes, and the genetic ties that bind us all.

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