Changes

Many Retrovirus genomes contain oncogenes which may be expressed when integrated to the host genomes. However, oncogenes are not a requirement for tumour induction, and some Retroviruses can cause tumours without carrying oncogenes. The Retroviral genome has four coding regions. The "gag" region codes for the matrix protein, nucleoprotein and capsid, and "pro" encodes a protease¹. Reverse transcriptase is coded by the "pol" region, whereas "env" gives rise to the envelope and receptor binding. An additional, specific cellular transporter RNA is required for replication and present within the virion.

Many Retrovirus genomes contain oncogenes which may be expressed when integrated to the host genomes. However, oncogenes are not a requirement for tumour induction, and some Retroviruses can cause tumours without carrying oncogenes. The Retroviral genome has four coding regions. The "gag" region codes for the matrix protein, nucleoprotein and capsid, and "pro" encodes a protease¹. Reverse transcriptase is coded by the "pol" region, whereas "env" gives rise to the envelope and receptor binding. An additional, specific cellular transporter RNA is required for replication and present within the virion.

FIV was first discovered in a cat rescue facility in the

FIV was first discovered in a cat rescue facility in the United States where cats had been showing similar clinical signs to people with acquired immunodeficiency syndrome². Subsequently it has been shown that FIV has been present in the cat population since the late 1960s, and that the virus is very similar to the human retrovirus, HIV. However, despite these similarities, FIV is specific to cats, and people cannot become infected with the virus.

United States where some of the cats had been showing

similar clinical signs to people with acquired immunodeficiency

syndrome (AIDS). The virus has subsequently been

data that FIV has been in the cat population since at least

the late 1960s. The prevalence of infection varies hugely

from country to country. In the UK, around 7 per cent of

the healthy and 19 per cent of the sick cat population are

infected with the virus (Hosie and others 1989).

Although there are many similarities between HIV and

FIV, the viruses are species specific and there is no

zoonotic risk to people in contact with an FIV-positive cat.

==Transmission and Epidemiology==

==Transmission and Epidemiology==