If you have ever received a blood transfusion, along with the red blood cells, leukocytes, plasma and other components, you also were infused with a collection of viruses. A recent study of the blood virome of over 8,000 healthy individuals revealed 19 different DNA viruses in 42% of the subjects. Viral DNA sequences were identified among the genome …
A key step in sexual reproduction is the fusion of haploid cells to form a diploid zygote, yet the molecular mechanism underlying this joining of cells is poorly understood. Two studies reveal amazing similarities between proteins required for fusion of sperm and egg, and virus with host cells. A screen for genes that cause male sterility in the flowering plant Arabidopsis led to …
The obligate intracellular bacteria Wolbachia (pictured), which infects 40% of arthropods, can manipulate its host to ensure its maintenance in the population. An example is cytoplasmic incompatibility, which occurs when infected males mate with uninfected females, and causes embryonic lethality (mating with an infected female produces viable offspring). Two Wolbachia genes responsible for this phenotype have been …
Transmissible spongiform encephalopathies (TSEs) are rare, but always fatal, neurodegenerative disorders of humans and other mammals. They are characterized by long incubation periods, spongiform changes in the brain associated with loss of neurons, and the absence of host responses. TSEs are caused by infectious proteins called prions. Insight into how prions cause TSEs comes from the observation that …
A study of sexual transmission of Zika virus among mice (link to paper) demonstrates beautifully that viral nucleic acid detected by polymerase chain reaction (PCR) is not the same as infectious virus. Male mice were infected with Zika virus and then mated with female mice. Efficient sexual transmission of the virus from males to females was observed. This …
Bacteriophages are the most abundant biological entities on Earth. There are 1031 of them on the planet, and they infect 1023 to 1025 bacteria every second. That’s a lot of lysis, and it leads to the release of huge quantities of DNA that can be taken up by other organisms, leading to new traits. It …
