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The Mysterious Dance of the Cricket Embryos

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In June, 100 fruit fly scientists gathered on the Greek island of Crete for their biennial meeting. Among them was Cassandra Extavour, a Canadian geneticist at Harvard University. Her lab works with fruit flies to study evolution and development — “evo devo.” Most often, such scientists choose as their “model organism” the species Drosophila melanogaster — a winged workhorse that has served as an insect collaborator on at least a few Nobel Prizes in physiology and medicine.

But Dr. Extavour is also known for cultivating alternative species as model organisms. She is especially keen on the cricket, particularly Gryllus bimaculatus, the two-spotted field cricket, even though it does not yet enjoy anything near the fruit fly’s following. (Some 250 principal investigators had applied to attend the meeting in Crete.)

“It’s crazy,” she said during a video interview from her hotel room, as she swatted away a beetle. “If we tried to have a meeting with all the heads of labs working on that cricket species, there might be five of us, or 10.”

Crickets have already been enlisted in studies on circadian clocks, limb regeneration, learning, memory; they have served as disease models and pharmaceutical factories. Veritable polymaths, crickets! They are also increasingly popular as food, chocolate-covered or not. From an evolutionary perspective, crickets offer more opportunities to learn about the last common insect ancestor; they hold more traits in common with other insects than fruit flies do. (Notably, insects make up more than 85 percent of animal species).

Dr. Extavour’s research aims at the fundamentals: How do embryos work? And what might that reveal about how the first animal came to be? Every animal embryo follows a similar journey: One cell becomes many, then they arrange themselves in a layer at the egg’s surface, providing an early blueprint for all adult body parts. But how do embryo cells — cells that have the same genome but aren’t all doing the same thing with that information — know where to go and what to do?

“That’s the mystery for me,” Dr. Extavour said. “That’s always where I want to go.”

Seth Donoughe, a biologist and data scientist at the University of Chicago and an alumnus of Dr. Extavour’s lab, described embryology as the study of how a developing animal makes “the right parts at the right place at the right time.” In some new research featuring wondrous video of the cricket embryo — showing certain “right parts” (the cell nuclei) moving in three dimensions — Dr. Extavour, Dr. Donoughe and their colleagues found that good old-fashioned geometry plays a starring role.

Humans, frogs and many other widely studied animals start as a single cell that immediately divides again and again into separate cells. In crickets and most other insects, initially just the cell nucleus divides, forming many nuclei that travel throughout the shared cytoplasm and only later form cellular membranes of their own.

In 2019, Stefano Di Talia, a quantitative developmental biologist at Duke University, studied the movement of the nuclei in the fruit fly and showed that they are carried along by pulsing flows in the cytoplasm — a bit like leaves traveling on the eddies of a slow-moving stream.

But some other mechanism was at work in the cricket embryo. The researchers spent hours watching and analyzing the microscopic dance of nuclei: glowing nubs dividing and moving in a puzzling pattern, not altogether orderly, not quite random, at varying directions and speeds, neighboring nuclei more in sync than those farther away. The performance belied a choreography beyond mere physics or chemistry.

“The geometries that the nuclei come to assume are the result of their ability to sense and respond to the density of other nuclei near to them,” Dr. Extavour said. Dr. Di Talia was not involved in the new study but found it moving. “It’s a beautiful study of a beautiful system of great biological relevance,” he said.

The cricket researchers at first took a classic approach: Look closely and pay attention. “We just watched it,” Dr. Extavour said.

They shot videos using a laser-light sheet microscope: Snapshots captured the dance of the nuclei every 90 seconds during the embryo’s initial eight hours of development, in which time 500 or so nuclei had amassed in the cytoplasm. (Crickets hatch after about two weeks.)

Typically, biological material is translucent and difficult to see even with the most souped-up microscope. But Taro Nakamura, then a postdoc in Dr. Extavour’s lab, now a developmental biologist at the National Institute for Basic Biology in Okazaki, Japan, had engineered a special strain of crickets with nuclei that glowed fluorescent green. As Dr. Nakamura recounted, when he recorded the embryo’s development the results were “astounding.”

That was “the jumping-off point” for the exploratory process, Dr. Donoughe said. He paraphrased a remark sometimes attributed to the science fiction author and biochemistry professor Isaac Asimov: “Often, you’re not saying ‘Eureka!’ when you discover something, you’re saying, ‘Huh. That’s weird.’”

Initially the biologists watched the videos on loop, projected onto a conference-room screen — the cricket-equivalent of IMAX, considering that the embryos are about one-third the size of a grain of (long-grain) rice. They tried to detect patterns, but the data sets were overwhelming. They needed more quantitative savvy.

Dr. Donoughe contacted Christopher Rycroft, an applied mathematician now at the University of Wisconsin-Madison, and showed him the dancing nuclei. ‘Wow!’ Dr. Rycroft said. He had never seen anything like it, but he recognized the potential for a data-powered collaboration; he and Jordan Hoffmann, then a doctoral student in Dr. Rycroft’s lab, joined the study.

Over numerous screenings, the math-bio team contemplated many questions: How many nuclei were there? When did they start to divide? What directions were they going in? Where did they end up? Why were some zipping around and others crawling?

Dr. Rycroft often works at the crossroads of the life and physical sciences. (Last year, he published on the physics of paper crumpling.) “Math and physics have had a lot of success in deriving general rules that apply broadly, and this approach may also help in biology,” he said; Dr. Extavour has said the same.

The team spent a lot of time swirling ideas around at a white board, often drawing pictures. The problem reminded Dr. Rycroft of a Voronoi diagram, a geometric construction that divides a space into nonoverlapping subregions — polygons, or Voronoi cells, that each emanate from a seed point. It’s a versatile concept that applies to things as varied as galaxy clusters, wireless networks and the growth pattern of forest canopies. (The tree trunks are the seed points and the crowns are the Voronoi cells, snuggling closely but not encroaching on one another, a phenomenon known as crown shyness.)

In the cricket context, the researchers computed the Voronoi cell surrounding each nucleus and observed that the cell’s shape helped predict the direction the nucleus would move next. Basically, Dr. Donoughe said, “Nuclei tended to move into nearby open space.”

Geometry, he noted, offers an abstracted way of thinking about cellular mechanics. “For most of the history of cell biology, we couldn’t directly measure or observe the mechanical forces,” he said, even though it was clear that “motors and squishes and pushes” were at play. But researchers could observe higher-order geometric patterns produced by these cellular dynamics. “So, thinking about the spacing of cells, the sizes of cells, the shapes of cells — we know they come from mechanical constraints at very fine scales,” Dr. Donoughe said.

To extract this sort of geometric information from the cricket videos, Dr. Donoughe and Dr. Hoffmann tracked the nuclei step-by-step, measuring location, speed and direction.

“This is not a trivial process, and it ends up involving a lot of forms of computer vision and machine-learning,” Dr. Hoffmann, an applied mathematician now at DeepMind in London, said.

They also verified the software’s results manually, clicking through 100,000 positions, linking the nuclei’s lineages through space and time. Dr. Hoffmann found it tedious; Dr. Donoughe thought of it as playing a video game, “zooming in high-speed through the tiny universe inside a single embryo, stitching together the threads of each nucleus’s journey.”

Next they developed a computational model that tested and compared hypotheses that might explain the nuclei’s motions and positioning. All in all, they ruled out the cytoplasmic flows that Dr. Di Talia saw in the fruit fly. They disproved random motion and the notion that nuclei physically pushed each other apart.

Instead, they arrived at a plausible explanation by building on another known mechanism in fruit fly and roundworm embryos: miniature molecular motors in the cytoplasm that extend clusters of microtubules from each nucleus, not unlike a forest canopy.

The team proposed that a similar type of molecular force drew the cricket nuclei into unoccupied space. “The molecules might well be microtubules, but we don’t know that for sure,” Dr. Extavour said in an email. “We will have to do more experiments in the future to find out.”

This cricket odyssey would not be complete without mention of Dr. Donoughe’s custom-made “embryo-constriction device,” which he built to test various hypotheses. It replicated an old-school technique but was motivated by previous work with Dr. Extavour and others on the evolution of egg sizes and shapes.

This contraption allowed Dr. Donoughe to execute the finicky task of looping a human hair around the cricket egg — thereby forming two regions, one containing the original nucleus, the other a partially pinched-off annex.

Then, the researchers again watched the nuclear choreography. In the original region, the nuclei slowed down once they reached a crowded density. But when a few nuclei sneaked through the tunnel at the constriction, they sped up again, letting loose like horses in open pasture.

This was the strongest evidence that the nuclei’s movement was governed by geometry, Dr. Donoughe said, and “not controlled by global chemical signals, or flows or pretty much all the other hypotheses out there for what might plausibly coordinate a whole embryo’s behavior.”

By the end of the study, the team had accumulated more than 40 terabytes of data on 10 hard drives and had refined a computational, geometric model that added to the cricket’s tool kit.

“We want to make cricket embryos more versatile to work with in the laboratory,” Dr. Extavour said — that is, more useful in the study of even more aspects of biology.

The model can simulate any egg size and shape, making it useful as a “testing ground for other insect embryos,” Dr. Extavour said. She noted that this will make it possible to compare diverse species and probe deeper into evolutionary history.

But the study’s biggest reward, all the researchers agreed, was the collaborative spirit.

“There’s a place and time for specialized knowledge,” Dr. Extavour said. “Equally as often in scientific discovery, we need to expose ourselves to people who aren’t as invested as we are in any particular outcome.”

The questions posed by the mathematicians were “free of all sorts of biases,” Dr. Extavour said. “Those are the most exciting questions.”

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The Best Fashion Instagrams of the Week: Zendaya, the Biebers, Kendall Jenner, and More

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Among the many things we gave thanks for on Thursday are the best fashion instagrams of the week. We’re mostly kidding, but there were some stellar looks these past seven days. First up, was sun-drenched Zendaya, who posed in a sand-colored cropped cardi in front of, well, a dune. Perhaps, she is on the set of…Dune

Justin and Hailey Bieber headed to Japan to celebrate Mrs. Bieber’s birthday. The duo were dressed in their coziest clothes: Justin opted for a pale yellow sweatsuit with a beanie and hulking chain, while Hailey wore an oversized collar shirt with sweats. While it’s not a high fashion moment, we did learn that Justin has a cute nickname for his wife thanks to his love-packed caption: “bum bum”.

Kendall Jenner went the less clothed route in an outré way. Taking a mirror selfie, she wore a cozy black sweater, but in lieu of pants or a skirt, the model opted for a pair of black tights. An even bolder moment? Jenner stepped out in the look, which was captured by paparazzi. 

Finally, Devon Lee Carlson is putting her twist on the latest suiting craze. The phone case influencer wore a super polished ’90s-era suit with a cubicle-ready belt, but with a tiny playful colorful graphic T-shirt and red sneakers for a casual touch. Hire us, Carlson! 

Here, see the best fashion Instagrams of the week. 

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American Rituals

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Abiquiú, New Mexico

At the Monastery of Christ in the Desert, a remote abbey beside the Chama River in northern New Mexico, some two dozen Benedictine monks begin their days in darkness.

At 3:30 a.m. one Sunday this past winter, a bell summoned the monks to vigils, the night prayer. Under a clear sky full of stars, they made their way in silence from their cloister cells to an adobe chapel. Seated in wooden pews, the brothers, most in black habits, began chanting the first of 12 psalms. They used the ancient Gregorian melody, but with English words: “O Lord, open my lips, and my mouth shall proclaim your praise.”

The sky was still dark when a second bell rang, just before 6, calling the monks to the dawn prayer, lauds. Back in the chapel, now wearing white cowls over their habits, they chanted again. As they began Psalm 150 — “Praise God in his holy place” — the tall windows above the sanctuary turned from black to midnight blue, the first hint of daybreak.

The sun rose over the next hour, illuminating the chapel’s backdrop — the Mesa de las Viejas, whose 500-foot rock walls faded from red to shades of sand and cream in a glowing gradient. Save for the faint rush of the Chama River, a sage green tributary of the Rio Grande, the canyon was soundless.

The setting was carefully chosen. The Rev. Aelred Wall, who founded the monastery in 1964, had scoured the country for a spot where he and his brother monks could “return to the sources” — to the quiet and isolation necessary for their contemplative vocation. Passing through New Mexico, he heard about an old ranch house for sale 75 miles northwest of Santa Fe — 115 acres along the Chama, surrounded by national forest.




The adobe chapel of the Monastery of Christ in the Desert.

Father Wall found the property at the end of a 13-mile dirt road. He sent an ecstatic letter to his friends at the Mount Saviour Monastery in Elmira, N.Y., waxing poetic about the river valley and its “great sentinels” of colorful cliffs. “Then came the cathedrals in stone, some of them Romanesque, some of them Gothic,” he wrote.

Father Wall bought the ranch house. He asked his friend George Nakashima, the master woodworker and architect, to design a chapel.

The chapel was built of adobe in the shape of a Greek cross, with arms of equal length, using clay from the site. Hand-carved doors were brought from Mexico, the bell from an old church in the northern New Mexican village of Questa. The artist Ben Shahn, a friend of Mr. Nakashima’s, contributed two large stained-glass windows. Georgia O’Keeffe, who lived 25 miles away, in Abiquiu, served as an artistic consultant.

Set against the towering cliffs, the adobe chapel looks otherworldly. The Cistercian monk and writer Thomas Merton, who visited the monastery in 1968, once likened its bell tower to “a watchman looking for something or someone of whom it does not speak.”

Shortly after 9 a.m., the bell rang again, for Mass. About 20 visitors settled into chairs in the back of the chapel. Abbot Christian Leisy, in purple vestments, walked around the altar, swinging a thurible of smoldering incense. Smoke swirled and billowed in the light as it rose.




The Tabernacle in the Abbey Church.



Brother Bede in the Cloister.



Brother Chrysostom held a rosary.

A monk read from the Book of Baruch: “Take off your robe of mourning and misery; put on the splendor of glory from God forever.” The second reading was from Paul’s letter to the Philippians. The Gospel was from the third chapter of Luke, in which John calls on the people of Judea to repent and be baptized and “prepare the way of the Lord.”

Abbot Christian’s homily noted that the first lines of the Gospel situated us in history — “the 15th year of the reign of Tiberius Caesar, when Pontius Pilate was governor of Judea.” Luke, he said, wants us to understand that these events really happened. The passage is also a reminder that God often surprises. God intervenes on the margins, speaking not through Caesar or Pontius Pilate, but through John — “someone unknown, someone living in the desert, eating wild honey and insects.”

Abbot Christian closed by reading a Jewish folk tale from the philosopher Martin Buber. It told of a Rabbi Eisik, in Krakow, who dreams three times that someone suggests he look for treasure under a bridge in Prague. The rabbi travels to Prague, only to learn that the treasure was at home, buried under his stove.

After Mass, most of the monks retreated to private quarters. A boisterous group from the Washington National Cathedral migrated over to the gift shop and loaded up on wares made by the brothers: goat-milk soap; scented candles; their latest album of Gregorian chant, “Blessings, Peace, and Harmony.”

Shortly after 11 a.m. the bell rang again, calling the monks. As the visitors drove off in a caravan, sending dust clouds into the blue sky, the brothers filed back into the chapel. — Abby Aguirre




The Monastic Cemetery near the chapel.

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Sweating Through a Honeymoon in Paradise

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Listen. I can be laid back when I have to be. I have been known to wait five or six hours before answering the occasional email. I have at times neglected to shake a towel vigorously before using it, risking unknown vermin latching onto my vulnerable, naked body. So when my husband and I decide to honeymoon in Bali, I have faith I will be able to enjoy it. To appreciate the views of unadulterated nature as I drift up and down a luxurious hotel infinity pool. And not necessarily think about, say, what kind of exotic parasites might potentially be inserting themselves into my vagina within said infinity pool.

At some point, perhaps basking in the glow of our travel agent’s enthusiasm, I must have decided my rampant O.C.D. wouldn’t be able to follow me to Bali, through interminable customs lines and sprawling opulent resorts and into the river-facing hotel spa where the woman in charge of my three-and-a-half-hour massage is now telling me to relax.

A three-and-a-half-hour massage is long. Longer than James Cameron’s “Titanic.” As the masseuse cakes my back with mud, I wonder what would be happening right now in “Titanic” if I had started it at the same time as this massage. Would Jack be learning to use utensils yet? Or would the ship be filling up with water already and I can break free sooner than I thought because time stops still here and in fact all notion of time as I know it has changed, and I will now understand time as a circle like Amy Adams’s character in “Arrival”?

“Relax,” the masseuse whispers as she applies pressure to my very tense neck, and I try not to think about the mysterious animal feces I found on the floor of our bungalow last night which my husband, in a bout of self-preservation, attempted to convince me were just a bit of rubble.

After the massage, in an attempt to relax further, I scan our bedroom floor with the iPhone flashlight because the lighting in the room is elegantly dim and by elegantly I mean frustratingly for someone who is not planning to engage in seduction at any point during this trip. I look up different critter feces on Google. I conclude the ones dotting our bungalow floor are salamander feces.

“Salamanders are great!” my mom gushes over our WhatsApp call, which I have initiated in a whispered panic from the locked bathroom so my husband won’t accuse me of failing to enjoy our honeymoon.

The smart toilet keeps greeting me, its lid opening and closing with a little whir, confused as to why I’m not using it.

“Salamanders eat all the bugs! They’re there to help you!” my mom says with forceful enthusiasm.

I do not ask her what if a salamander’s feces drops from the ceiling into my mouth because I’ve noticed her patience run short with this type of question over the years.

In the morning I am awakened by what I assume are ambulances but which are allegedly cicadas. My left ankle is swollen with two mosquito bites. I suffer from “skeeter syndrome,” which means mosquito bites on my skin distend to tumoral degrees and erupt in tiny welts. So the salamanders are clearly not doing their job, or: there are so many mosquitoes in this room their predators are sated and unable to eat them all — a frightening prospect.

I casually let this information drop as our concierge drives us through the resort in a buggy, a frangipani flower tucked behind his ear. He promises to fix the bug problem and drops us off at the lobby. A car is taking us to a traditional Balinese dance at a nearby temple. It is on a cliff top with scenic views of the Indian Ocean and sheathed in what the internet calls a “peaceful ambience.”

According to my iPhone, there is 90 percent humidity during the outdoor dance. I presume 100 percent humidity involves drowning. Rivulets of sweat pour down my spine like caressing fingers. I spray DEET on myself so profusely I can taste the chemicals on my tongue through my nostrils. The sun sets and the temperature cools slightly. Then the dancers set the stone stage on fire.

Suddenly (to the tune of Wagner’s “Ride of the Valkyries,” in my head), swarms of moths the size of industrial pedestal fans descend from the heavens, slapping us in the face and alighting on our backs so that unacquainted audience members begin to pick them off one another in a display of solidarity. They’re just moths, relax, I repeat to myself, smiling emptily for my husband’s camera as the family seated behind me swat them off my shoulder blades.

Once the dance ends, our pores dilated from our impromptu steam bath, we make our way down the steep cliff to the parking lot, monkeys as big as dogs on either side of us, eyeing our purses and phones. One of them sits alarmingly close to our car. Our guide advises us to hide our jewelry and avoid eye contact.

When we return to the hotel, we find that a dramatic mosquito net has been swathed over the bed, and rubber has been stuffed into the window gaps. I DEET myself regardless. I trust no one.

On our last day in Bali my husband and I perform a Balinese wedding ceremony because it’s too late to cancel. The officiants warn us that they will sprinkle a little ceremonial water on us. We agree to this, and thus commences our soothing, spiritual journey. The priest proceeds to pour bowl after bowl of ceremonial water on our scalps. My makeup, hair and contact lenses stream down my cheeks. My eyes burn. I wonder if I could get a urinary tract infection this way. The priest sticks grains of rice to our dripping foreheads. They slide off and pellet our laps. The water never stops. It is more eternal than our love.

I count the hours until I return home. I berate myself for doing this, reminding myself this is the only trip of this scale I will ever take and as such it should be enjoyed.

On the two plane rides home I watch three “Bridget Jones” movies in a semi-catatonic state. I feel numb when we step into our apartment. I Google “Bali parasites you have to extract with tweezers from eyeballs weeks later.” The results are inconclusive. I start to relax. Then I notice them. Crawling up our kitchen walls. Pantry moth larvae. I cry a little bit. My husband cries a little bit. I miss Bali.

Episode is a column of first-person essays exploring a moment in a writer’s life. Virginia Feito is the author of the novel “Mrs. March” and a writer for Vanity Fair Spain. She lives in Madrid.

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