New methods of stem cell research emerge one after another.

2006 is the tenth anniversary of the birth of Dolly the cloned sheep, which should have been a day worth celebrating. However, sheep cloning technology was hit hard at the beginning of the year. Hwang Woo-suk's fraud scandal and US President Bush's veto of the H.R.8 10 bill passed by the US Congress-the stem cell research enhancement bill.

But in March this year, German researchers reported that they had transformed spermatogenic cells extracted from adult mouse testes into cells very similar to embryonic stem cells.

In August this year, Japanese scientists announced another way to make "personalized" cells without cloning. A month later, a European research team announced that they had cultivated human embryonic stem cells from a "stagnant" in vitro fertilized embryo. This fertilized embryo refers to an embryo that stops dividing before reaching the parthenogenesis stage and naturally "dies" as a result.

Found new organs in mice

Mice are the most common experimental animals. They are often cut open, but biologists never expect to find new organs in mice they come into contact with almost every day. In April, 2006, Hans-Remo Rodewald, an immunologist in university of ulm, Germany, announced that he had discovered another kind of thymus, the cervical thymus, while dissecting experimental mice with thoracic thymus diseases. Both thymus organs produce immune cells called T lymphocytes. The newly discovered organ is located in the neck, which is only a fraction of the size of a mouse's chest thymus. Biologists are currently conducting a large-scale investigation, trying to find a second human organ that may also be ignored.

HIV originated from wild chimpanzees.

Researchers have long suspected the origin of chimpanzee HIV- 1, but there has been a lack of evidence to prove this view. The research team led by Beatrice Hahn, a medical professor at the University of Alabama in Birmingham, USA, found antibodies to HIV- 1 precursors and nucleic acids of the virus itself in the feces of wild chimpanzees. HIV- 1 virus apparently originated in the southern forest of Cameroon in central Africa, and later spread along the Sangha River to Kinshasa, the capital of the Democratic Republic of the Congo, where scientists found the first recorded case of human HIV infection.

The uterus determines a man's sexual orientation.

In the past ten years, a large number of studies have shown that there is a correlation between male sexual orientation and the number of blood brothers. The latest research found that an important factor of this association is their biological mother. Anthony bogart, a psychologist at Brook University, Ontario, found that male sexual orientation may be caused by the mother's immune system responding to protein produced by male fetus. Bogart hopes to further study this possibility in future research.

Arthropod: the "bee" of spore plants

According to biology textbooks, male mosses mate in a very unique way: sperm flow to the surrounding rain or dew fog-a dangerous strategy that appeared in ancient aquatic algae. But Swedish researchers announced in September this year that in fact, arthropods may play an intermediary role in the mating process of moss. This kind of assisted reproduction is thought to have first appeared 65.438+0.4 billion years ago, and insects began to collect and spread pollen between flowering plants. Nowadays, research shows that this method may have been used for a long time, about 440 million to 470 million years ago, shortly after plants first opened up land territory. Arthropods are willing to act as media because they get some rewards. This is obviously similar to bee pollination.

Current accelerates wound healing and even regeneration.

/kloc-In the middle of the 9th century, Emile du powys-Raymond, a famous German physiologist, measured a current passing through the injured part after his arm was injured, indicating that the pain induced an electronic signal. In July this year, Zhao Min, a biomedical professor at Aberdeen University, announced that electric current can accelerate wound healing and even regeneration. Zhao Min and his colleagues used electric current to guide epithelial cells into and out of damaged tissues of mouse cornea. In addition, they found that the speed at which epithelial cells move is directly proportional to the applied voltage. Zhao Min said that their next step will be to study the healing characteristics of electric current at the genetic level.

Worms can survive without a gastrointestinal system.

Olaviusalgarvensis is a small marine oligochaeta worm, which lives in shallow sand along the Mediterranean coast. In the long process of evolution, their physical characteristics have changed greatly, not only without mouth, stomach and intestine, but also without excretory organs. On the contrary, they only live on various bacteria that live under the skin. What is even more surprising is that a tacit cooperative relationship has been formed between the host and the parasite.

Edward Rubin, director of the Joint Genome Research Institute in Walnut Creek, California, said: "They provide energy. On the one hand, they feed the bugs well, and on the other hand, they help them clean up the garbage. " In return, bacteria can stay or move freely on worms. This is the first time to analyze the genome of such a complex relationship. Gene sequencing of parasitic bacteria is carried out in the Joint Genome Research Institute.

New monkey species discovered in Tanzania

This year, biologists added a new branch to our primate family tree. Scientists studied the gene of "Chipungi" monkey living in Tanzania and found that it belongs to a new primate genus, which is the first time that scientists have confirmed a new primate species in 83 years. Chiponji monkeys have light brown hair and are about three feet long. It can bark like a wild goose. It lives in hilly areas that are mostly ignored by scientists. It was originally called highland white eyebrow. At present, their number may be only 1000. Tim Davenport, a biologist with the International Wildlife Conservation Society, said, "If we don't find them now, this new monkey species may be on the verge of extinction before the scientific community realizes their existence."

Long-haired white crab was found at the bottom of the South Pacific Ocean.

This year, scientists discovered a fur-covered crustacean at the bottom of the South Pacific Ocean at a depth of 6,500 feet. After investigation, it was confirmed as a new species and classified into a new family, Kiwaidae. This white crab is six inches long and has no eyes. Its claws are covered with filaments like human hair, which are filled with things that are most likely bacteria. Joe Jones of Monterey Bay Aquatic Animal Research Institute discovered this hairy crab and named it Snowman, a hairy humanoid animal that is said to live in the Himalayas. Joe Jones found it when he was driving the submersible Alvin to explore the deep-sea hydrothermal vent.

Super ant "fly"

Hollywood may be at its wit's end about how to create Superman, but nature has not lost this ability. This year, biologists discovered a super ant in a study. Their mouths are so tight that they can even eject themselves into the air with a hard bite. In order to generate the necessary strength, they will open their jawbones, tighten their muscles, and then suddenly relax. The strength of the mandible will then increase to a terrible speed, just as a person's fingers suddenly loosen when bitten. Scientists use high-speed video with a resolution of 70,000 frames per second to analyze the bite force of ants, and find that they have the fastest self-propelled attack in the animal kingdom, and can even bite off the bones and muscles of shrimp in one bite.

Spread cancer in dogs

Robin Weiss, a viral oncologist at University College London, first heard that cancer can spread in dogs through sexual contact more than 20 years ago. Today, he found an amazing clue that this cancer originated from the ancestors of canines hundreds or thousands of years ago. The sarcoma discovered by Weiss grows on the genitals of dogs, and some early genetic evidence shows that this sarcoma will spread from dog to dog. In order to find relevant evidence, Weiss and experienced veterinarian Claudio Murchia collected the DNA of sarcoma samples from various dogs around the world, and all the sarcoma DNA of these dogs did not match the sarcoma DNA they found. On the contrary, cells prove that they originated from a single primitive sarcoma, spread from dog to dog through body fluids and sexual contact, and passed down from generation to generation. Dog sarcoma has aroused the curiosity of the medical community. They have become the oldest known mammalian cell line and a new parasite. This parasite is unusual and may not be suitable for any current classification standard.

Similar cancer cell lines may exist in other animals, including humans, but Weiss thinks they are quite rare.

Measuring the number of giant pandas with DNA

A new study on DNA analysis of giant panda feces shows that there may be about 3,000 giant pandas living in China at present, which is twice the previous estimate. Before this study, estimating the number of giant pandas was largely an art: detecting bamboo fragments in the feces of giant pandas, looking at bite marks and distinguishing different giant pandas. However, Michael Bruford, a geneticist at Cardiff University in Wales, pointed out that the bite marks of different giant pandas on bamboo look very similar, so researchers inadvertently underestimated the real number of giant pandas. He said: "We are not saying that the giant panda is out of danger, but with the increase of protection, the future of the giant panda will be brighter in the long run." Yang Xiaowen