Viruses are widely distributed in nature, which can infect bacteria, fungi, plants, animals and people, and often cause host diseases. But in many cases, the virus can coexist with the host without causing obvious diseases.
Cafeteria rumbergen virus
The discovery of Rosenberg syndrome virus in cafeteria blurs the boundary between living organisms and non-living organisms. Cafeteria roenbergensis is the largest and most complex marine virus in the world, which mainly infects predators that feed on plankton, which is very important and widely distributed in marine ecosystems. Most viruses are very light. They only carry a few genes needed to synthesize new viruses and rely on their host mechanism to complete the rest of the work. From 20 10 to 10, Matthias G. Fischera of the University of British Columbia in Vancouver and his colleagues discovered a flying virus called Cafeteria roenbergensis, which carried an incredible 730,000 DNA base pairs, including more than 500 similar gene regions. 20 10, 101October 25th, the researchers reported this research result in the online edition of Proceedings of the National Academy of Sciences (PNAS). This also makes this virus the largest known marine virus, with more DNA than some bacteria.
This virus mainly infects predators that feed on plankton, which is very important and widely distributed in marine ecosystems. The genome of this virus is larger than that of some cell organisms. In addition, Cafeteria roenbergensis virus has become the largest marine virus in the world, and it is also the second largest virus (20 10 and 10) known at present, second only to the freshwater virus-Acanthamoeba polymyxovirus, which has10.2 million base pairs. This virus may also be the representative of a large group of unknown but ecologically important marine giant viruses.
Researchers speculate that compared with smaller viruses, such as HIV (H Ⅳ) or herpes virus, this virus-which can infect Cafeteria roenbergensis, a predatory single-celled organism that preys on marine bacteria and other viruses-has played a more active role in the synthesis of its protein. The researchers pointed out that the virus has a large number of genes, which are usually used by living cells to repair their DNA damage and synthesize protein and sugar. It also has some protein genes needed for virus replication, but it must be obtained from the host organism.
Scientists generally don't classify viruses as living things, because viruses can't replicate independently, but giant viruses like this-with their own protein synthesis mechanism and other functions that can usually be accomplished in living cells-blur the boundaries between what is living things and what is not. The only known large virus can infect freshwater amoeba and is considered to be a close relative.
Influenza virus is named according to its surface structure. H stands for hemagglutinin, whose function is to enable the virus to combine with the host cell; N stands for neuraminidase, whose function is to release self-replicating virus from cells. H in influenza A can be divided into 16 subtype, and N can be divided into 9 subtypes. All these virus subtypes were isolated from birds. 1. Respiratory virus and enterovirus
Measles virus, poliovirus, Coxsackie virus
Second, arboviruses and hemorrhagic fever viruses
Japanese encephalitis virus, dengue virus, hemorrhagic fever virus, hantavirus, Ebola virus.
Third, rabies virus and retrovirus.
Rabies virus, human immunodeficiency virus, human T cell virus
Fourth, hepatitis virus.
Hepatitis A virus, hepatitis B virus, hepatitis C virus, hepatitis D virus and hepatitis E virus.
Verb (abbreviation for verb) herpes virus
Herpes simplex virus, varicella zoster virus, cytomegalovirus, EBV
Intransitive verbs and other viruses
Human papillomavirus, rotavirus, coronavirus, rubella virus.