In 1998, a millimetre-long nematode worm was the first animal to have its whole genome sequenced<\/a>. The human genome was first sequenced<\/a> just five years later, although it was not absolutely completed until 2021.<\/p>\n A genome is the instructions for making an animal, written in a chemical code known as DNA. Genomics looks beyond genes to all the DNA found between the genes. Establishing \u201creference genomes\u201d for species can help scientists better study organisms\u2019 biology and evolution, as well as identify new medicines and compounds.<\/p>\n Witek Morek collects tardigrade samples from moss on the grounds of the Wellcome Sanger Institute. Photograph: Ali Smith\/The Guardian<\/p>\n Sequencing genomes used to take years. Blaxter sequenced 18 genomes over 25 years of study in his early career. Now, the Tree of Life programme is sequencing 48 each week, thanks to advances in sequencing technology. It has sequenced 2,600 genomes so far, from whales to fungi, mostly focusing on British and Irish species.<\/p>\n And now it is the turn of microscopic tardigrades \u2013 the popular winner of last year\u2019s Guardian invertebrate of the year contest<\/a>.<\/p>\n About 1,500 species of tardigrade \u2013 the name means \u201cslow stepper\u201d \u2013 have been identified around the world so far. They are famously indestructible<\/a>, able to survive searing heat, extreme cold and even a spell in outer space. This is because of their ability to dessicate and enter a suspended animation, until they are reawakened by water.<\/p>\n A lichen sample is placed in a beaker of water. Thirty minutes later, the tardigrades are wiggling away. Photograph: Ali Smith\/The Guardian<\/p>\n Morek begins the sequencing process by putting the moss and lichen samples he has collected in a beaker of water. Thirty minutes later, the tardigrades are wiggling away.<\/p>\n He places tiny pieces of moss beneath a microscope and soon identifies a tardigrade. It is waggling its chubby-baby legs. This \u201cmoss piglet\u201d is a translucent, middle-sized tardigrade, about 350 micrometres in length (a human hair is 50 micrometres in diameter). It has recently eaten: Morek can see the contents of its gut.<\/p>\n Morek, who has so far collected about 20 of the 50 tardigrades on the British list (a \u201chuge underestimate\u201d of the total species number, he says), will need to see its eggs to identify this exact species. Some tardigrades have smooth eggs; others have mushroom, conical or needle-like shapes on the surface.<\/p>\n Tardigrades can be \u201cvoracious carnivores, chasing down nematodes and eating them like spaghetti\u201d, says Morek. But he also reveals how they can demonstrate parental care. A mother sometimes sheds its cuticle (its skin) with eggs safely inside the shed skin. But she keeps the cuticle attached to her legs until the eggs are hatched.<\/p>\n A tardigrade from the Echiniscus genus. Morek has so far collected about 20 of the 50 tardigrades on the British list. Photograph: Wellcome Sanger Institute<\/p>\n Morek makes a temporary slide \u2013 putting the tardigrade between glass \u2013 to confirm its taxonomy as closely as possible. It has to be temporary because the water will evaporate and the tardigrade could be crushed by the glass.<\/p>\n The tardigrade is kept alive and transferred to a barcoded plastic tube. This is frozen for later sequencing \u2013 kept in the lab\u2019s special double-doored freezers set at -71C.<\/p>\n Morek examines slides that store tardigrade samples. Photograph: Ali Smith\/The Guardian<\/p>\n There are four high-quality tardigrade genomes deposited in public databases, Morek is closely working on another 14, and there are approximately 50 species in the freezer awaiting sequencing.<\/p>\n Before extracting the DNA for sequencing, Witek must \u201cmanually disrupt\u201d his specimen. He can cut a 200-micrometre tardigrade by hand or use a form of mashing within a block of ice when frozen.<\/p>\n A tardigrade contains a tiny amount of DNA, just 200 to 500 picograms (one picogram is one trillionth of a gram). In the old days, researchers would need to pool 1,000 tardigrades to obtain enough DNA, an arduous process which was impossible with rare or hard-to-find species. Another strategy is to use a single female to produce large numbers of genetic clones.<\/p>\n But the Wellcome Sanger Institute deploys a different approach: the picogram inputi multimodal sequencing protocol.<\/p>\n skip past newsletter promotion<\/a><\/p>\n Sign up to Down to Earth<\/p>\n The planet’s most important stories. Get all the week’s environment news – the good, the bad and the essential<\/p>\n after newsletter promotion<\/p>\n With this technique, genomic DNA and RNA are extracted from the tardigrade and separated into two tubes. Researchers then use a polymerase chain reaction (PCR) to amplify these fragments to create enough material.<\/p>\n Tardigrade samples removed from a storage freezer. Photograph: Ali Smith\/The Guardian<\/p>\n The quality of the DNA produced is checked and samples are handed to the institute\u2019s scientific operations team. After it is sequenced, the data is available on the institute\u2019s computer cluster. The sequence itself is millions-long strings of the four types of bases found in a DNA molecule: adenine, cytosine, guanine and thymine (ACTG).<\/p>\n Fortunately for tardigrade researchers, tardigrade genomes are small \u2013 30 times smaller than the human genome. Although the PCR process is complex, scientists require less data to assemble the genome of a tardigrade.<\/p>\n For Morek, the sequencing of tardigrades will help reveal how species are related to each other. Incredibly, some tardigrades are separated by 550m years of evolution.<\/p>\n But genome sequencing could also reveal how the tardigrades\u2019 superpowers \u2013 such as resistance to freezing (cryobiosis), resistance to a lack of oxygen (anoxybiosis) and the ability to repeatedly survive desiccation (anhydrobiosis) \u2013 may help us.<\/p>\n Examining tardigrade samples as seen through a microscope. Photograph: Ali Smith\/The Guardian<\/p>\n \u201cAnd, because most of life on this planet is small, like the tardigrades, this new approach to genome sequencing promises to open the gates to sequencing all of life,\u201d says Blaxter. \u201cThese genomes will in turn open up new ideas and opportunities in biomedicine and biotechnology.\u201d<\/p>\n Through sequencing, scientists can pinpoint the genes and proteins required for these processes. If a certain protein is crucial in anhydrobiosis, can we use it to produce vaccines which are dry, or add it to crops to make them more drought-resistant?<\/p>\n \u201cThere are a lot of research questions,\u201d says Morek. \u201cThe more we know, the more questions we are asking. It\u2019s a never-ending story.\u201d<\/p>\n Invertebrate of the year is here for 2026<\/p>\n The tardigrade won last year, but who will triumph in 2026? The whistle has been blown to launch the third invertebrate of the year contest.<\/p>\n We, creatures with spines, are a tiny minority in the animal world. Humans, dogs, cows, birds, fish \u2013 we may think we\u2019re the planetary rulers but we\u2019re not. We make up barely 5% of animal life on Earth; but on the other side there are at least 1.3 million invertebrate species to choose from.<\/p>\n We want you to nominate your favourite spineless creature for the hugely popular annual Guardian jamboree which celebrates the wonder and importance of the world\u2019s invertebrates. Without the unseen labours of our unheralded neighbours \u2013 the snails, spiders, sponges, corals, bivalves, wasps and crabs \u2013 the grandiose edifice that is human civilisation would crumble.<\/p>\n These are our pollinators, soil-makers, fertility-bringers, water-cleaners, predator- and plague-controllers. A few invertebrates may still wreak havoc in the human world but as the legendary biologist EO Wilson<\/a> put it: \u201cThe truth is that we need invertebrates but they don\u2019t need us.\u201d<\/p>\n![\"\"](\"https:\/\/www.newsbeep.com\/ca\/wp-content\/uploads\/2026\/06\/500.jpg\")
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