Welcome to the collection of resources at NCBI specifically designed to support the research of retroviruses.

The family Retroviridae comprises a variety of enveloped RNA viruses, such as endogenous retroviruses, leukemia viruses, and HIV-1, the replicative strategy of which includes as essential steps reverse transcription of the virion RNA into linear double-stranded DNA and the subsequent integration of this DNA into the genome of the cell.

The virion RNA is 7 to 12 kb long, linear, single-stranded, non-segmented, and of positive polarity. All retroviruses contain the gag, pro, pol, and env genes. In addition, some retroviruses also contain the dut gene and the complex retroviruses (Deltaretroviruses, Spumaretroviruses, Lentiviruses), which include HIV-1, contain additional regulatory proteins.

Available tools and information

• Browse and select retrovirus reference genomes by taxonomy
• Blast protein and nucleotide sequences against retroviral sequences
• Determine the genotype (and possible recombination breakpoints) of HIV-1 sequences