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Cancer, Clinical Trials, Dermatology, Genetics, Pain, Pediatrics, Research, Stanford News

The worst disease you’ve never heard of: Stanford researchers and patients battle EB

The worst disease you've never heard of: Stanford researchers and patients battle EB

EB patient and docsI’m often humbled by my job. Well, not the job, exactly, but the physicians, researchers, and especially patients who take the time to speak with me about their goals and passions, their triumphs and fears. Their insight helps me as I struggle to interpret what goes on here at the Stanford University School of Medicine for others across the university and even around the world.

But every once in a while, an article comes along that brings me to my (emotional) knees. My article “The Butterfly Effect” in the latest issue of Stanford Medicine magazine describes the toll of a devastating skin disease called epidermoloysis bullosa on two young men and their families, as well as the determined efforts of a dedicated team of doctors and scientists to find a treatment. As a result, Stanford recently launched the world’s first stem-cell based trial aimed at correcting the faulty gene in the skin cells of patients with a severe form of the condition, which is often called EB.

I trace the path of one family as they learn, mere hours after his birth, that their son, Garrett Spaulding, has EB, which compromises the ability of the outer layers of the to stick together during friction or pressure. Patients develop large blisters and open wounds over much of their bodies. It’s incurable, fatal, and nearly indescribably painful. Paul Khavari, MD, PhD, now the chair of Stanford’s Department of Dermatology, was a young doctor at the time newborn Garrett was admitted to Lucile Packard Children’s Hospital Stanford in 1997.

“His whole body, his skin was blistered and falling off everywhere someone had touched him,” Khavari recalls in the article. “His parents were devastated, of course, at a time that was supposed to be one of the most joyful of their lives.”

Garrett’s now 18 years old, but the disease is taking its toll.

You’ll also meet Paul Martinez, one of the first participants in Stanford’s new clinical trial. He’s 32, which makes him an old man in the EB community. Unlike many EB patients, he has finished high school and completed a college degree in business marketing with a dogged determination that makes me ashamed of my petty complaints about my minor life trials. And he’s done it without relying on the pain medications essential for most EB patients. As he explains in the article:

We don’t know what it is like to not be in pain. It’s just normal for us. […] I have a very high tolerance, and don’t take any pain medication. I cherish my mind a lot. Rather than feel like a zombie, I prefer to feel the pain and feel alive.

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Genetics, In the News, Research, Science, Stanford News, Stem Cells, Technology

CRISPR marches forward: Stanford scientists optimize use in human blood cells

CRISPR marches forward: Stanford scientists optimize use in human blood cells

The CRISPR news just keeps coming. As we’ve described here before, CRISPR is a breakthrough way of editing the genome of many organisms, including humans — a kind of biological cut-and-paste function that is already transforming scientific and clinical research. However, there are still some significant scientific hurdles that exist when attempting to use the technique in cells directly isolated from human patients (these are called primary cells) rather than human cell lines grown for long periods of time in the laboratory setting.

Now pediatric stem cell biologist Matthew Porteus, MD, PhD, and postdoctoral scholars Ayal Hendel, PhD, and Rasmus Bak, PhD, have collaborated with researchers at Santa Clara-based Agilent Research Laboratories to show that chemically modifying the guide RNAs tasked with directing the site of genome snipping significantly enhances the efficiency of editing in human primary blood cells — an advance that brings therapies for human patients closer. The research was published yesterday in Nature Biotechnology.

As Porteus, who hopes to one day use the technique to help children with genetic blood diseases like sickle cell anemia, explained to me in an email:

We have now achieved the highest rates of editing in primary human blood cells. These frequencies are now high enough to compete with the other genome editing platforms for therapeutic editing in these cell types.

Porteus and Hendel previously developed a way to identify how frequently the CRISPR system does (or does not) modify the DNA where scientists tell it. Hendel characterizes the new research as something that will allow industrial-scale manufacturing of pharmaceutical-grade CRISPR reagents. As he told me:

Our research shows that scientists can now modify the CRISPR technology to improve its activity and specificity, as well as to open new doors for its use it for imaging, biochemistry, epigenetic, and gene activation or repression studies.

Rasmus agrees, saying, “Our findings will not only benefit researchers working with primary cells, but it will also accelerate the translation of CRISPR gene editing into new therapies for patients.”

Onward!

(Those of you wanting a thorough primer on CRISPR —how it works and what could be done with it — should check out Carl Zimmer’s comprehensive article in Quanta magazine. If you prefer to learn by listening (perhaps, as I sometimes do, while on the treadmill), I found this podcast from Radiolab light, but interesting.)

Previously: Policing the editor: Stanford scientists devise way to monitor CRISPR effectiveness and “It’s not just science fiction anymore”: Childx speakers talk stem cell and gene therapy

 

Evolution, Genetics, Research, Science, Stanford News

Kennewick Man’s origins revealed by genetic study

Kennewick Man's origins revealed by genetic study

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One day in 1996, on the banks of the Columbia River near Kennewick, Washington, two men found a human skull about ten feet from shore. Eventually, the nearly complete skeleton of an adult man was unearthed and found to be nearly 9,000 years old.

Since that find, controversy has swirled as to whether the man was an ancestor of Native American tribes living in the area, or was more closely related to other population groups around the Pacific Rim. A study published in 2014, based in part on anatomical measurements, concluded that the skeleton, known as the Kennewick Man, was more likely related to indigenous Japanese or Polynesian peoples.

Now Stanford geneticists Morten Rasmussen, PhD, and Carlos Bustamante, PhD, working with Eske Willerslev, PhD, and others at the University of Copenhagen’s Centre for GeoGenetics have studied tiny snippets of ancient DNA isolated from a hand bone. They’ve compared these DNA sequences with those of modern humans and concluded that the Kennewick Man (known to many Native Americans as the Ancient One) is more closely related to Native American groups than to any other population in the world.

The findings are published today online in Nature, and they’re likely to reignite an ongoing controversy as to the skeleton’s origins and to whom the remains belong.

As Rasmussen said in our press release:

Due to the massive controversy surrounding the origins of this sample, the ability to address this will be of interest to both scientists and tribal members. […]

Although the exterior preservation of the skeleton was pristine, the DNA in the sample was highly degraded and dominated by DNA from soil bacteria and other environmental sources. With the little material we had available, we applied the newest methods to squeeze every piece of information out of the bone.

Increasingly, such methods of isolating and sequencing ancient DNA are being used to solve millennia-old mysteries, including those surrounding Otzi the Iceman and a young child known as the Anzick boy buried more than 12,000 years ago in Montana.

Bustamante explained in the release:

Advances in DNA sequencing technology have given us important new tools for studying the great human diasporas and the history of indigenous populations. Now we are seeing its adoption in new areas, including forensics and archeology. The case of Kennewick Man is particularly interesting given the debates surrounding the origins of Native American populations. Morten’s work aligns beautifully with the oral history of native peoples and lends strong support for their claims. I believe that ancient DNA analysis could become standard practice in these types of cases since it can provide objective means of assessing both genetic ancestry and relatedness to living individuals and present-day populations.

Previously: Caribbean skeletons hold slave trade secrets,  Melting pot or mosaic? International collaboration studies genomic diversity in Mexico and  On the hunt for ancient DNA, Stanford researchers improve the odds
Photo, of bust showing how Kennewick Man may have looked, by Brittany Tatchell/Smithsonian (bust by StudioEIS; forensic facial reconstruction by sculptor Amanda Danning)

Big data, Cancer, Genetics, Research, Science, Stanford News

Stanford researchers suss out cancer mutations in genome’s dark spots

Stanford researchers suss out cancer mutations in genome's dark spots

lighted pathOnly a small proportion of our DNA contains nucleotide sequences used to make proteins. Much of the remainder is devoted to specifying how, when and where those proteins are made. These rules are encoded in our DNA as regulatory elements, and they’re what makes one cell type different from another, and keep them from running wild like children in an unattended classroom. When things go awry, the consequences (like rampant growth and cancers) can be severe.

Geneticist Michael Snyder, PhD, and postdoctoral scholar Collin Melton, PhD, recently combined information from The Cancer Genome Atlas, a national effort to sequence and identify mutations in the genomes of many different types of cancers, with data from the national ENCODE Project, which serves as an encyclopedia of DNA functional regions, or elements. Their aim was to better understand the roles that mutations in regulatory regions may play in cancer development.

Snyder and Melton found that fewer than one of every thousand mutations in each cancer type occurs in the coding region of a gene. In contrast, more than 30 percent of the mutations occur in regulatory regions. The study was published this morning in Nature Genetics.

As Snyder explained to me:

Until recently, many mutations outside the coding regions of genes have been mostly invisible to us. Cancer researchers largely focused on identifying changes within coding regions. Using ENCODE data, we’ve been able to define some important regions of the genome and found that certain regulatory regions are often enriched for mutations. This opens up a whole new window for this type of research.

Snyder, who leads Stanford’s genetics department and directs the Stanford Center for Genomics and Personalized Medicine, likens looking for cancer-causing mutations only in coding regions as “looking under the lamppost” for keys lost at night. Until recently, the coding regions of genes were the most well-studied, and unexpected mutations stood out like a sore thumb. We’ve known there’s a lot more of the genome outside the coding regions, but until the ENCODE project was largely completed in 2012, researchers were often in the dark as to where, or even how, they should look.

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Autism, Mental Health, Neuroscience, Research, Science, Stanford News, Stem Cells

Brain cell spheres in a lab dish mimic human cortex, Stanford study says

Brain cell spheres in a lab dish mimic human cortex, Stanford study says

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Mental disorders like autism and schizophrenia are notoriously difficult to study at the molecular level. Understandably, people are reluctant to donate pieces of living brain for study, and postmortem tissue lets researchers see the structure, but not the function, of the cells.

Now researchers in the laboratories of psychiatrist Sergiu Pasca, MD, and neurobiologist Ben Barres, MD, PhD, have found a way to make balls of cells that mimic the activity of the human cortex. They use a person’s skin cells, so the resulting “human cortical spheroid” has the same genetic composition as the donor. The research was published in Nature Methods yesterday.

According to our release:

Previous attempts to create patient-specific neural tissue for study have either generated two-dimensional colonies of immature neurons that do not create functional synapses, or required an external matrix on which to grow the cells in a series of laborious and technically difficult steps.

In contrast, the researchers found they were able to easily make hundreds of what they’ve termed “human cortical spheroids” using a single human skin sample. These spheroids grow to be as large as 5 millimeters in diameter and can be maintained in the laboratory for nine months or more. They exhibit complex neural network activity and can be studied with techniques well-honed in animal models.

The researchers, which include neonatology fellow Anca Pasca, MD, and graduate student Steven Sloan, hope to use the technique to help understand how the human brain develops, and what sometimes goes wrong. As described by Barres:

The power and promise of this new method is extraordinary. For instance, for developmental brain disorders, one could take skin cells from any patient and literally replay the development of their brain in a culture dish to figure out exactly what step of development went awry — and how it might be corrected.

The research is starting to garner attention, including this nice article from Wired yesterday. Pasca’s eager to note, however, that he’s not working to create entire brains, which would be ethically and technically challenging, to say the least. But simply generating even a few of the cell types in the cortex will give researchers a much larger canvas with which to study some devastating conditions. As Pasca notes in our release:

I am a physician by training. We are often very limited in the therapeutic options we can offer patients with mental disorders. The ability to investigate in a dish neuronal and glial function, as well as network activity, starting from patient’s own cells, has the potential to bring novel insights into psychiatric disorders and their treatment.

Previously: More than just glue, glial cells challenge neuron’s top slot and Star-shaped cells nab new starring role in sculpting brain circuits
Photo of spheroid cross-section by Anca Pasca

Cancer, Research, Science, Stanford News

Kidney cancer secrets revealed by Stanford researchers

Kidney cancer secrets revealed by Stanford researchers

I enjoyed recently writing about a collaboration among researchers from Stanford’s School of Medicine and the School of Humanities and Sciences. Oncologist Dean Felsher, MD, PhD, and chemist Richard Zare, PhD, joined forces to learn more about a kidney cancer called renal cell adenocarcinoma; their research was published in the Proceedings of the National Academy of Sciences earlier this week.

In the future, we hope to use this model to… identify those kidney cancer patients who might respond favorably to specific therapies

Together Felsher and Zare found that an aggressive form of kidney cancer has a distinct lipid profile (lipids are a class of molecules found in cell membranes; they also function in cellular signaling pathways and in energy storage). To do so, they used a new technology called desorption electrospray ionization mass-spectrometric imaging, or DESI-MSI. It sounds complicated, but it led directly to a new, previously unsuspected therapeutic approach that may soon be tested in humans. As I described in my article:

DESI-MSI creates a highly detailed, two-dimensional map of the chemical composition of a tissue sample through a process that can be loosely compared to a specialized car wash. Samples are sprayed with a thin, high-powered stream of liquid droplets that dissolve their outer surface. The resulting back spray, which contains molecules from the surface of the sample, is collected and analyzed by mass spectrometry. By moving the tissue sample around in a two-dimensional plane, it’s possible to make a chemical map of its composition.

The researchers found that the cancerous kidney tissue had a chemical composition distinct from that of healthy tissue. In particular, it had higher-than-normal levels of molecules generated as glutamine is metabolized. Blocking the activity of a protein called glutaminase, which is responsible for metabolizing glutamine, caused the animals’ tumors to grow more slowly when [Myc expression was activated].

To conduct the work, researchers in Felsher’s laboratory genetically engineered a strain of mice that could be triggered to express high levels of a cancer-associated protein called Myc in the tubules of their kidneys. These mice quickly developed an aggressive form of kidney cancer when Myc was expressed. Conversely, the kidney tumors shrank significantly when Myc expression was halted. As Felsher told me:

In the future, we hope to use this model to categorize different types of kidney cancer and identify those patients who might respond favorably to specific therapies. In the near term, we can test whether blocking glutamine metabolism is a viable approach for people with Myc-dependent liver cancer.

Previously: Unraveling the secrets of a common cancer-causing gene and Smoking gun or hit-and-run? How oncogenes make good cells go bad

Evolution, Genetics, Microbiology, Pregnancy, Research, Science, Stanford News, Stem Cells

My baby, my… virus? Stanford researchers find viral proteins in human embryonic cells

My baby, my... virus? Stanford researchers find viral proteins in human embryonic cells

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One thing I really enjoy about my job is the opportunity to constantly be learning something new. For example, I hadn’t realized that about eight percent of human DNA is actually left-behind detritus from ancient viral infections. I knew they were there, but eight percent? That’s a lot of genetic baggage.

These sequences are often inactive in mature cells, but recent research has shown they can become activated in some tumor cells or in human embryonic stem cells. Now developmental biologist Joanna Wysocka, PhD, and graduate student Edward Grow, have shown that some of these viral bits and pieces spring back to life in early human embryos and may even affect their development.

Their research was published today in Nature. As I describe in our press release:

Retroviruses are a class of virus that insert their DNA into the genome of the host cell for later reactivation. In this stealth mode, the virus bides its time, taking advantage of cellular DNA replication to spread to each of an infected cell’s progeny every time the cell divides. HIV is one well-known example of a retrovirus that infects humans.

When a retrovirus infects a germ cell, which makes sperm and eggs, or infects a very early-stage embryo before the germ cells have arisen, the viral DNA is passed along to future generations. Over evolutionary time, however, these viral genomes often become mutated and inactivated. About 8 percent of the human genome is made up of viral sequences left behind during past infections. One retrovirus, HERVK, however, infected humans repeatedly relatively recently — within about 200,000 years. Much of HERVK’s genome is still snuggled, intact, in each of our cells.

Wysocka and Grow found that human embryonic cells begin making viral proteins from these HERVK sequences within just a few days after conception. What’s more, the non-human proteins have a noticeable effect on the cells, increasing the expression of a cell surface protein that makes them less susceptible to subsequent viral infection and also modulating human gene expression.

More from our release:

But it’s not clear whether this sequence of events is the result of thousands of years of co-existence, a kind of evolutionary symbiosis, or if it represents an ongoing battle between humans and viruses.

“Does the virus selfishly benefit by switching itself on in these early embryonic cells?” said Grow. “Or is the embryo instead commandeering the viral proteins to protect itself? Can they both benefit? That’s possible, but we don’t really know.”

Wysocka describes the findings as “fascinating, but a little creepy.” I agree. But I can’t wait to hear what they discover next.

Previously: Viruses can cause warts on your DNA, Stanford researcher wins Vilcek Prize for Creative Promise in Biomedical Science and Species-specific differences among placentas due to long-ago viral infection, say Stanford researchers
Photo of Joanna Wysocka by Steve Fisch

Cancer, Genetics, Patient Care, Research, Science, Stanford News

Identifying relapse in lymphoma patients with circulating tumor DNA

Identifying relapse in lymphoma patients with circulating tumor DNA

3505577004_6fc17ba8c2_zCancer patients in remission often live on a knife’s edge, wondering if their disease will recur. This possibility is more likely in some types of cancers than in others. One of these is diffuse large B-cell lymphoma, which is the most common blood cancer in this country. It’s often successfully treated, but a significant minority of patients will relapse. Detecting these relapses early is critical, but difficult.

Hematologist and oncologists Ash Alizadeh, MD, PhD, and David Kurtz, MD, and former postdoctoral scholar Michael Green, PhD, wanted to find a better way to track disease progression in these patients. They’ve developed a new technique, published Friday in the journal Blood, that is more accurate and can detect relapses earlier than conventional methods.

“As a clinician, I care for many of these patients,” Alizadeh explained to me. “Detecting relapse can be very difficult. It would be a major step forward to develop a way to identify these patients before they become sick again.”

Detecting relapse can be very difficult. It would be a major step forward to develop a way to identify these patients before they become sick again.

The researchers turned to what’s known as circulating tumor DNA in the blood. The approach, which was pioneered by Stanford bioengineer Stephen Quake, PhD, relies on the idea that when the cells in our body die, they rupture and release their contents, including their DNA, into our bloodstream. Tracking the rise and fall of the levels of these tiny snippets of genetic information can give insight into what is happening throughout the body.

When a B cell becomes cancerous, it begins to divide uncontrollably. Each of these cancer cells shares the DNA sequence of the original cell; as the cells multiply, so does the overall amount of that DNA sequence in the body. Alizadeh and his colleagues wondered whether tracking the levels of cancer-specific DNA in a patient’s blood could help them identify those patients in the early stages of relapse.

Currently patients in remission are monitored for relapse with regular physical exams and blood tests. Imaging techniques such as PET or CT scans can be used to look for residual disease, but they don’t detect every case, and often deliver false positive results. They are also costly and expose the patient to DNA-damaging radiation that could potentially cause secondary cancers years later.

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Research, Science, Stanford News, Surgery

Will scars become a thing of the past? Stanford scientists identify cellular culprit

Will scars become a thing of the past? Stanford scientists identify cellular culprit

346801775_c5a1e37a6d_zI have a scar on my chin from a fall I took while rollerskating when I was about 12. One minute I was blithely zooming along to Bob Seger’s hit Against the Wind (earworm alert!), reveling in my new ability to skillfully cross one foot in front of the other and thinking about that cute boy by the snack counter, and the next I was chin down skidding across the flat, grey and (I then realized) very hard floor to come to rest against the wooden wall in an ignominious heap.

Although the experience left an impression on my psyche, as well as my skin, I can’t claim any long-lasting problem from the thin line on my chin. After all, nearly all of us have something similar. But scars can also be debilitating and even dangerous.

Now plastic and reconstructive surgeon Michael Longaker, MD, and pathologist and stem cell expert Irving Weissman, MD, have identified the cell type in mice that is responsible for much of the development of a scar. They’ve shown that blocking this cell’s activity with a small molecule can reduce the degree of scarring. Because a similar drug molecule is already approved for use in humans to treat Type 2 diabetes, the researchers are hopeful that they can begin clinical trials in humans soon. The research was published today in Science.

As Longaker explained in our release on the study:

The biomedical burden of scarring is enormous. About 80 million incisions a year in this country heal with a scar, and that’s just on the skin alone. Internal scarring is responsible for many medical conditions, including liver cirrhosis, pulmonary fibrosis, intestinal adhesions and even the damage left behind after a heart attack.

Longaker and his colleagues found that a subset of a skin cell called a fibroblast is responsible for much of the collagen deposition that leads to scarring. Inhibiting the activity of a protein on the surface of the cells significantly reduced the amount of scarring during wound healing in laboratory mice – from about 30 percent of the original wound area down to about 5 percent -the researchers found. Furthermore, they showed the cells are also involved in the thickening and darkening of skin exposed to radiation therapy for cancer, as well as the spread of melanoma cancer cells in the animals.

Longaker’s been interested in how the skin heals for decades–ever since he learned as a student that, prior to the third trimester, human fetuses heal from trauma or surgery without any scarring. Now he’s excited to learn whether there’s a way to recapture that long-lost ability as adults and at least reduce the degree of scarring during skin repair.

“I’ve been obsessed with scarring for 25 years,” Longaker told me. “Now we’re bringing together the fields of wound healing and tumor development in remarkable new ways. It’s incredibly exciting.”

Longaker and Weissman are both also members of the Stanford Cancer Institute.

Previously: New medicine? A look at advances in wound healing, Stanford-developed device shown to reduce the size of existing scars in clinical trial and Mast cells not required for wound healing, according to Stanford study
Photo by Paulo Alegria

Genetics, Research, Science, Stanford News

When X+X = X: Stanford scientists shed light on X-inactivation

When X+X = X: Stanford scientists shed light on X-inactivation

2189014070_339cb830f9_z-1With apologies to some of my colleagues (cough, Margarita Gallardo, cough), I’ve never really enjoyed the Garfield comic strip. The rotund cartoon cat and his insatiable lasagna cravings has always seemed odd to me. Plus, most orange and black cats are female, due to a curious biological phenomenon called X inactivation.

The inactivation of one X chromosome in female animals (and humans) is necessary to ensure that both sexes end up with roughly the same dosage of X-chromosome associated genes. In most species, the chromosome to be inactivated is selected randomly in each cell early in development, and the selected chromosome remains inactive in all of the cell’s subsequent progeny. Researchers believe that X inactivation might explain at least in part why some diseases are more prevalent or severe in one gender than the other.

Now dermatologist Howard Chang, MD, PhD, and former graduate student Ci Chu, PhD, have shed some light on the process, which occurs through the action of a regulatory RNA molecule called Xist. Their research was published today in Cell.

From our release:

[The researchers] have outlined the molecular steps of inactivation, showing that it occurs in an orderly and directed fashion as early embryonic cells begin to differentiate into more specialized tissues. They’ve identified more than 80 proteins in mouse cells that bind to Xist to help it do its job. They hope their findings will shed light on conditions in humans that are typically more severe in one gender than the other.

“We see some very interesting phenomena with X-linked diseases in humans,” said [Chang]. “Often, when the faulty gene is on the X chromosome, the condition is more severe in boys. This happens in hemophilia, for example. In contrast, women are far more likely than men to suffer from autoimmune diseases, for reasons we don’t yet understand. This research opens the door to possibly understanding the biological basis for these differences.”

The researchers were able to pinpoint the protein partners of Xist only after Chu developed an entirely new technique. More from our release:

Chu’s technique, which the researchers call CHIRP-MS for “comprehensive identification of RNA-binding proteins by mass spectrometry,” allowed the researchers to identify the sequential interaction of over 80 proteins with Xist during X inactivation. Many of these proteins have never before been associated with that process. It’s thought that they may help target and anchor Xist to active genes along the length of the X chromosome like burrs on a shoelace after a hike in the woods.

“If you lay all the copies of Xist in a cell end to end, they are not long enough to coat the entire X chromosome,” said Chang. “Instead, Xist spreads judiciously, finding active genes and shutting them down. It also must stay anchored to the chromosome and not float over to any other chromosomes in the nucleus. This requires an elaborate set of machinery that we believe acts in a sequential fashion.”

Specifically, the researchers suspect that some proteins help Xist locate and silence active genes, while others work to maintain that silencing once it has been established.

Clearly X inactivation is a complex process. But are you still wondering about Garfield? Because the genes for “orange” or “black” fur occur on the X chromosome, female cats that carry one of each version can be a patchwork of the two colors, depending on which chromosome is inactivated. Blobs of orange fur indicate an ancestor cell in which the chromosome with the black fur gene was inactivated, and vice versa. But a male cat, with only one X chromosome can only be orange or black, but not both.

An exception would be a male cat who had inherited two X chromosomes and one Y (in humans, this is called Klinefelter syndrome). This genetic anomaly, which is found in about one of every 3,000 calico cats, would likely have other oddities, however. Perhaps even a craving for pasta, cheese and tomato sauce?

Previously: Tomayto, tomahto: Separate genes exert control over differential male and female behaviors, Does it matter which parent your “brain genes” came from? and Stanford professor encourages researchers to take gender into account
Photo by Jerry Knight

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