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I spent a year of college teaching rats to find their way through a maze, and now I find that slime molds, which don’t even have brains, can do the same thing! Professor Toshiyuki Nakagaki of Japan’s Future University Hakodate studies slime molds, which organize their colonies of cells to move toward a food source, using the most direct route.
“Humans are not the only living things with information-processing abilities,” he said. “Simple creatures can solve certain kinds of difficult puzzles. If you want to spotlight the essence of life or intelligence, it’s easier to use these simple creatures.”
The research in slime mold organization may lead to information-processing breakthroughs, including the possibility of biocomputers. Link -via Arbroath
(Image credit: Flickr user Sentrawoods)
People who make toys, dollhouses, or other miniatures know that certain laws of physics apply that make miniaturization difficult. Certain laws of biology apply, too, but the fairy wasp seems to do an end-run around some of those rules. How else could an insect exist that is smaller than many single-celled creatures? Some are revealed by Alexey Polilov from Lomonosov Moscow State University, who has studied these tiny wasps for years.
Polilov found that M.mymaripenne has one of the smallest nervous systems of any insect, consisting of just 7,400 neurons. For comparison, the common housefly has 340,000 and the honeybee has 850,000. And yet, with a hundred times fewer neurons, the fairy wasp can fly, search for food, and find the right places to lay its eggs.
On top of that Polilov found that over 95 per cent of the wasps’s neurons don’t have a nucleus. The nucleus is the command centre of a cell, the structure that sits in the middle and hoards a precious cache of DNA. Without it, the neurons shouldn’t be able to replenish their vital supply of proteins. They shouldn’t work. Until now, intact neurons without a nucleus have never been described in the wild.
And yet, the fairy wasp has thousands of them. As it changes from a larva into an adult, it destroys the majority or its neural nuclei until just a few hundred are left. The rest burst apart, saving space inside the adult’s crowded head. But the wasp doesn’t seem to suffer for this loss. As an adult, it lives for around five days, which is actually longer than many other bigger wasps. As Zen Faulkes writes, “It’s possible that the adult life span is short enough that the nucleus can make all the proteins the neuron needs to function for five days during the pupal stage.”
There are other tricks tiny insects use to maintain life in miniature, which you can read at Not Exactly Rocket Science. Link
Henrietta Lacks, an impoverished tobacco farmer in Virginia, contracted cervical cancer in 1951. Her doctor gave a sample of her tumor to a medical researcher, who then used it to grow a cell culture. What’s amazing is that in almost sixty years, those cells are still alive, making them the longest-living human cells grown in a laboratory. Journalist Rebecca Skloot has written a book about Lacks and her cells, and submitted to an interview with Smithsonian:
Henrietta’s cells were the first immortal human cells ever grown in culture. They were essential to developing the polio vaccine. They went up in the first space missions to see what would happen to cells in zero gravity. Many scientific landmarks since then have used her cells, including cloning, gene mapping and in vitro fertilization.
Skloot writes about how scientists are using these unusual cells to study human immunity. But her book is also about how the scientific world collided with a largely illiterate family and how the human body has become a commodity.
Link | Photo: Lacks family, via Smithsonian
This is a fun little learning tool, provided by The University of Utah. Use the slider bar to zoom smaller and smaller in scale, from 12 millimeters (coffee bean) to 140 picameters (carbon atom), and track progress with the graph in the upper left. And if something looks fishy about that sperm cell…
How can an X chromosome be nearly as big as the head of the sperm cell?
No, this isn’t a mistake. First, there’s less DNA in a sperm cell than there is in a non-reproductive cell such as a skin cell. Second, the DNA in a sperm cell is super-condensed and compacted into a highly dense form. Third, the head of a sperm cell is almost all nucleus. Most of the cytoplasm has been squeezed out in order to make the sperm an efficient torpedo-like swimming machine.
Link via Twisted Sifter
What better way to get kids interested in biology at an early age than to make them their very own plush cell? Instructables has all the info you need to make your very own cuddly block of life.
Scientists have grown this Gumby/gingerbread man shape out of living human cancer cells!
The structure was grown using about 100,000 beads of the connective protein collagen, seeded with cells from a human liver cancer culture and tipped into a body-shaped mould. On the surface of each bead are cells of a type that secrete proteins and collagen that bind all the cells together.
Researchers are working to produce cell cultures that resemble organs in order to test new drugs. Link -via Culture Dish
