Summary

Scientists Discover the First Animal That Doesn’t Breathe Oxygen to Live

Jan 29, 2021 | 🚀 Fathership

Scientists have discovered the first multicellular creature that not only doesn't need oxygen to live, but can’t breathe even if it wanted to.

Maybe you remember this from high school biology: mitochondria are the powerhouses of the cell. That’s because of the key roles they play in breaking down nutrients and converting them into energy-rich molecules. This process is called aerobic respiration, and it’s the reason every animal has to breathe air—or so scientists thought.

Researchers have discovered an animal lacking a mitochondria and many of the genes that facilitate aerobic respiration. The animal is a salmon parasite called Henneguya salminicola, and it is a member of the phylum Cnidaria, which also contains jellyfish and sea anemones. The international team of researchers published a study with their results on Monday in the journal PNAS.

“Our discovery shows that aerobic respiration, one of the most important metabolic pathways, is not ubiquitous among animals,” the authors wrote in the study.

The history of the mitochondria is inextricably wrapped up in the history of eukaryotic organisms, the domain of organisms that includes all plant and animal life. Due to a set of similarities between mitochondria and bacteria, scientists believe that at least 1.45 billion years ago, a proto-mitochondrion was swimming around doing its thing when it was absorbed into another organism. Instead of digesting it, the organism kept it around and the two cells worked together in a mutually beneficial relationship.

H. salminicola is a micrometer-sized parasite that infects salmon and causes distinctive pseudocysts in the skeletal muscle of salmon. The parasite is commonly found in Alaska, and it causes a condition called “tapioca disease” or “milky flesh disease,” according to a field guide compiled by the Alaska Department of Fish and Game.

“The spores of this parasite occur in the muscle and under the skin of Pacific salmon causing a condition known as ‘milky flesh’ disease because of the creamy white fluid containing spores that oozes from the cysts (pansporoblasts) during filleting,” the field guide reads.

The researchers obtained samples of H. salminicola from Chinook and Coho salmon in Oregon and sequenced their genes along with those of Myxobolus squamalis, a close parasite relative. They looked at parasites from each species under a microscope after adding fluorescent dye that would bind to wherever the mitochondria were. To their surprise, the mitochondria of M. squamalis were clearly visible as small blue dots, but H. salminicola didn’t appear to have any mitochondria.

The genetic sequencing results painted a similar picture. M. squamalis had at least 41 genes likely used for mitochondrial processes, while H. salminicola only had six of these genes. One gene critical for replicating mitochondria had been turned into a pseudogene, making it functionally useless. H. salminicola also lacked many of the proteins that its relatives use in aerobic respiration.

Study senior author Dorothée Huchon said in an email that the discovery of an animal that could not undergo aerobic respiration was pure luck, as she had set out to sequence mitochondria across Myxozoa, the class of parasites to which H. salminicola belongs. She obtained frozen samples of myxozoans from co-author Stephen Atkinson’s lab in Oregon, and one of the samples happened to be H. salminicola.

“My goal was to assemble mitochondrial genome to study its evolution in Myxozoa and… Oops, I found one without a genome,” she said.

At first, Huchon thought it might be a mistake. “I first thought that the lack of mitochondrial genome among the DNA sequence was the result of a bug in genome analyses. But then I realized that it has lost not just the mitochondrial genome but the whole set of protein genes that interact with the mitochondrial genome and all the majority of genes involved in respiration.”

She added that Atkinson then performed the microscopy, which confirmed the molecular results and was “a relief.”

Of course, H. salminicola must have some way of breaking down nutrients. The scientists found mitochondria-related organelles when they viewed H. salminicola under an electron microscope. These organelles contained special folds called cristae that mitochondria also possess to increase the surface area where chemical reactions can take place; however, the ways in which these mitochondria-related organelles function are unknown, since the parasites were dead for these analyses. Additionally, the authors reported that it is “currently not possible” to culture H. salminicola in laboratory settings. Huchon said that this is because the parasite needs two hosts during its life cycle—a fish and a worm—and scientists do not yet know which worm it infects.

In the paper, the authors wrote that future experiments are needed to better understand H. salminicola’s metabolism. Still, the discovery underscores the ingenuity of myxozoans, the class of parasites to which H. salminicola belongs.

“Myxozoans have gone through outstanding morphological and genomic simplifications during their adaptation to parasitism from a free-living cnidarian ancestor,” the authors wrote. “As a highly diverse group with >2,400 species, which inhabit marine, freshwater, and even terrestrial environments, evolutionary loss and simplification has clearly been a successful strategy for Myxozoa, which shows that less is more.”

Like most evolutionary rulebreakers, H. salminicola goes against the definition of a eukaryote in unique and specific ways that make us question the rules in the first place, and appreciate the diversity of life on Earth.

Update: This article was updated with comment from study senior author Dorothée Huchon.

Unrepentant teen with a long list of offences is why some parents shouldn't breed

Nov 25, 2021 | 🚀 Fathership

Ralph Wee Yi Kai, a 19-year-old Singaporean man, has pleaded guilty to eight charges on Nov. 25 during his plead guilty mention before District Judge May Mesenas.

The charges include consuming weed, causing unnecessary suffering to a frog, possessing imitation tobacco products, trespassing into the rhinoceros enclosure at the Singapore Zoo, and committing mischief by damaging property, reported CNA.

Another six charges will be considered during his sentencing.

Probation is "not realistic"

Wee pleaded guilty via video link from his place in remand, where he has been since Nov. 6.

The prosecution strongly objected to a probation suitability report, noting that Wee is "beyond the control of his parents, which renders probation unsuitable", according to CNA.

The prosecution asserted that probation "is not realistic" for Wee, based on his repeated offences and conduct in court.

They cited his "blatant disregard for rules", and urged for a reformative training suitability report instead.

Deputy Public Prosecutor Melissa Lee said Wee "has a tendency to abuse drugs and alcohol", which caused him to behave aggressively towards his parents.

He also "posed a risk" to them, which led him to be admitted to the Institute of Mental Health.

"Never expected it to come to this"

Wee's defence lawyer Shashi Nathan requested for the addition of a probation suitability report, according to CNA.

Shashi maintains that his family is able to supervise Wee, and added that his client "comes from a good family" who are "able to look after him".

He said that Wee was undergoing "a severe emotional crisis" when he committed his offences, and shared that the case has also affected Wee's family, especially after their home address was released to the press.

"While Ralph understands that what he did was wrong, he never expected it to come to this," said Shashi.

Difference between probation and reformative training

Wee was ordered to go though both assessments for a probation suitability report and a reformative training report, reported Yahoo News.

Offenders who undergo probation will not have a criminal record, while reformative training, which provides a more structured environment, results in a criminal record.

What Wee's lawyer said

Wee's lawyer said his client acted out after breaking up with his girlfriend, 18, who was the one who filmed the video of Wee backflipping in the zoo.

The defence lawyer, Shashi, said Wee spiralled into an emotional crisis as a result of his break-up.

Wee is homeschooled.

The court was told Wee saw a video of a man riding a giraffe and decided to make a video in the rhino enclosure, Yahoo News reported.

The ex-girlfriend had filmed the act and posted it on her private Snapchat account.

Wee posted it on his public TikTok account and a police report was made by a zoo personnel within the same day.

Wee removed the video when he was told to do so by the police, but reposted it on Dec. 18, before being told to remove it again, claiming he thought the video had been made private when he reposted it.

Wee had also included a link in his Instagram account biography to directed to a page selling t-shirts with the words "rhino ralph".

But he denied creating the merchandise profile.

He later removed the link.

Wee will return to court on Dec. 20 for his sentencing.

Timeline of events with updated details

Oct. 9, 2020, 2:40am: Allegedly committed an act of vandalism by hitting an information panel at a bus stop in Sixth Avenue, off Bukit Timah Road, causing S$900 in damage.

Allegedly caused damage to two cars -- S$2,800 to a Mercedes-Benz and more than S$1,600 to a BMW -- in nearby Sixth Crescent.

A taxi driver passing by reported him to the police, as Wee was standing in the middle of the road with a beer bottle in hand.

Dec. 16, 2020: Wee was placed on compulsory supervision for 60 months from Dec. 16. He was required to present himself for urine tests on each Tuesday and Thursday, but failed to turn up on four occasions.

He was placed on e-tagging during this period of time, after having been charged for his earlier offences.

He had to stay at home from 10pm to 6am as part of his bail conditions.

Dec. 17, 2020, 2.40pm: Accused of trespassing into the rhinoceros enclosure and taking a video.

Dec. 18, 2020: Reposted zoo video, despite taking it down earlier after being told to do so by the police. Told to remove video again.

Dec. 24, 2020: Accused of abusing a frog, which subsequently died, by hitting a ball against it on a foosball table, causing "unnecessary pain and suffering".

The incident allegedly took place at a Sentosa Cove property.

July 2021: First hauled to court and charged with two counts of mischief, as well as one count each of vandalism and criminal trespass.

Bail was then set at S$15,000.

Aug. 6, 2021: Allegedly consumed cannabis while out on bail. Arrested at his residence and two urine samples obtained tested positive for weed. S$15,000 bail revoked.

Sep. 14, 2021: Allegedly possessed an e-vaporiser and six e-cigarette pods at a ward in the Institute of Mental Health.

Three police officers showed up at IMH, where Wee was warded, to arrest him for failing to attend court.

He was admitted to IMH due to his drug and alcohol abuse, as had acted aggressively towards his parents when they demanded the drugs from him.

He was warded in IMH due to the risk he posed to his parents.

Oct. 13, 2021: Charged with one count of drug consumption while still in remand.

Bail raised to S$20,000 and Wee was released.

While out on second bail, Wee committed a string of offences, including cutting his electronic tag, according to ST, as well as not reporting for his urine tests on a few occasions, CNA reported.

The prosecution has called for an urgent bail review hearing to have Wee's second bail revoked for the alleged fresh offences.

Oct. 26, 2021: Allegedly cut a S$100 GPS ankle tag at an address on Leedon Road at about 12:10am.

Prior to this act, Wee was upset at his father, who had asked Wee to sleep early since he had to report for his urine test in the morning.

After arguing with his father, Wee decided to leave the house, and used pliers to cut off his e-tag before cycling to his friend’s house.

Upon discovering that Wee was missing, his father called the police.

The e-tag, worth S$100, was damaged and could no longer be used.

It was found in Wee’s house.

Oct. 28, 2021: Allegedly possessed an e-cigarette pod at the Leedon Road address.

Nov. 5, 2021: Warrant of arrest issued, as Wee could not wake up to attend court.

Nov. 6, 2021: Wee arrested.

Nov. 12, 2021: Slapped with four additional charges.

Nov. 25, 2021: Pleaded guilty to consuming weed, causing unnecessary suffering to a frog, possessing imitation tobacco products, trespassing into a rhino enclosure, and committing mischief by damaging property belonging to others.

Ordered to go though assessments for a probation suitability report and a reformative training report.