Human Immunodeficiency Virus (HIV) is the causative agent of AIDS. It is a retrovirus belonging to the lentivirinae family. HIV reverse-transcribes its RNA to DNA and then back to RNA. HIV Infection Leeches and mosquitoes are unable to transmit HIV because the virion is unable to replicate outside of a warm mammalian host. Due to [...]

Like coronaviruses and flaviviruses, togaviruses have the following properties: + strand ssRNA genomes Use insects as secondary hosts Wide range and severity of diseases There are two classes of togaviruses: Alphaviruses The prototype is Sindbis, which forms very clean plaques; result in disease with an enormous range of symptoms. Rubiviruses The prototype is rubella; result [...]

Like togaviruses and flaviviruses, coronaviruses have the following properties: + strand ssRNA genomes Use insects as secondary hosts Wide range and severity of diseases Coronaviruses have a helical nucleocapsid. They also have an enormous genome (4-5 times larger than that of picornaviruses). While togaviruses use only two mRNAs to synthesize its proteins, coronaviruses use 7. [...]

The picornavirus family has these general properties: Large groups of viruses with common structure, genome organization, and expression Genome is a single strand of + sense RNA enclosed in an icosohedral non-enveloped capsid Causes a wide range of diseases including poliomyelities, enteitis, hepatitis, and common colds. The picornavirus family has these 5 genuses, with a [...]

Intro Bacteriophage M13 has a 6kb circular ssDNA genome. It is filamentous (as opposed to icosohedral). Special proteins at the tips are involved in assembly, morphogenesis, adsorption and penetration. It infects F+ E. coli, but rather than killing host cells it just slows growth. Virions leak out from the cell. Thus, the virus is not [...]

dsDNA 40kb genome. Complex icosohedral head & short tail. More completely dominates cell than M13. Replication cycle starts; within 6 minutes host cell protein synthesis shut off. Viral proteins completely degrade host cell DNA. Host nucleotides used for virion genome replication Per cell, virion makes 200 copies of viral DNA within 15-20 post-infection. T7 good [...]

Bacteriophage lambda (λ) was discovered by Joshua and Esther Lederberg. While mutagenizing strains E. coli using UV, a strain was found to be a lysogen. Genome is 48,502 bp dsDNA with 12 nucleotide ssDNA cohesive termini. Contained in capsid. Linear dsDNA circularizes due to annealing between 3′ sticky cos sites. The capsid has two parts: [...]