What is the genome size of HIV?

What is the genome size of HIV?

The genome consists of 9,200-9,600 nucleotides in the case of HIV-1 and approximately 9,800 nucleotides in the case of HIV-2 (drawing: Lutz Gürtler).

What are the evolutionary origins of HIV-1 and HIV-2?

Phylogenetic analysis indicates that multiple interspecies transmissions from simian species have introduced two genetically distinct types of HIV into the human population: HIV-1, closely related to simian immunodeficiency virus (SIV) from chimpanzees (SIVCPZ), and HIV-2, closely related to SIV from sooty mangabeys ( …

How does HIV demonstrate evolution?

Evolution through natural selection can be seen happening in real time by observing HIV, the virus that causes AIDS. HIV has been able to rapidly develop resistance to any drug developed to combat it due to the power of random variation acted upon by selective environmental pressure.

Is HIV-1 genetic?

HIV-1 is characterized by extensive genetic diversity. Mutational escape results in a remarkable degree of viral diversity within HIV-1 and in its adaptation to both immune activity and antiretroviral therapy.

How many rabies viruses are known till to date?

All extant rabies viruses appear to have evolved within the last 1500 years. There are seven genotypes of Rabies lyssavirus. In Eurasia cases are due to three of these—genotype 1 (classical rabies) and to a lesser extent genotypes 5 and 6 (European bat lyssaviruses type-1 and -2).

Do all viruses have integrase?

This protein, subsequently named integrase (IN), is one of three enzymes encoded in all retroviral genomes [protease (PR), RT, and IN]. All three viral enzymes are contained in virus particles, along with RNA genomes, and are carried into the cell following virus entry.

What animal carries rabies?

Any mammal can get rabies. The most common wild reservoirs of rabies are raccoons, skunks, bats, and foxes. Domestic mammals can also get rabies. Cats, cattle, and dogs are the most frequently reported rabid domestic animals in the United States.

Do human cells have integrase?

Integrase is also an attractive target because, like reverse transcriptase, no integrase activity is normally present in human cells. Once a cell is infected, an integrase inhibitor would not help the infected cell or reduce its production of new virions.

Which virus has integrase?

HIV PICs have been reported to contain the viral proteins integrase, nucleocapsid, matrix, reverse transcriptase and Vpr [8–15], in addition to a number of cellular proteins. PICs efficiently integrate their viral DNA into a target DNA in vitro with all the hallmarks of integration in vivo.

Where are the genes located in the HIV genome?

The genes of HIV are located in the central region of the proviral DNA and encode at least nine proteins ( Figure 1 ).( 2) These proteins are divided into three classes: 1 The major structural proteins, Gag, Pol, and Env 2 The regulatory proteins, Tat and Rev 3 The accessory proteins, Vpu, Vpr, Vif, and Nef More

Where are the splice acceptors located in the HIV genome?

Incompletely spliced RNA. These mRNAs use the splice donor site located nearest the 5′ end of the HIV RNA genome in combination with any of the splice acceptors located in the central region of the virus. These RNAs can potentially express Env, Vif, Vpu, Vpr, and the single-exon form of Tat.

Which is the first viral gene to accumulate to detectable levels?

Nef, an early gene of HIV, is the first viral protein to accumulate to detectable levels in a cell following HIV-1 infection. (49) Its name is a consequence of early reports claiming that Nef down-regulated transcriptional activity of the HIV-1 LTR. It is no longer believed, however, that Nef has a direct effect on HIV gene expression.

How does Tat affect the transcription of HIV?

Tat acts principally to promote the elongation phase of HIV-1 transcription, so that full-length transcripts can be produced. ( 40,41) In the absence of Tat expression, HIV generates primarily short (>100 nucleotides) transcripts.