The biochemistry of cell communication (Introduction)

by David Turell , Wednesday, October 19, 2016, 15:30 (2739 days ago) @ dhw

dhw: from a very different angle, an article in the Times caught my eye: since the 1990s the Tasmanian devil has been driven almost to extinction by a highly contagious form of cancer. In just four generations, however, there has been a “remarkable” genetic shift, and “the survivors appear to have a degree of immunity to the cancer, and go on to spread their genes throughout the local population

An example of genetic variability allows devils to survive with immunity is that some of them naturally carry generalized antibodies against the disease:

http://phys.org/news/2016-05-natural-antibodies-combat-tasmanian-devil.html

"Deakin University scientists may have found a way to stop the cancer that has been killing Tasmanian devils for the past 20 years.

"And the devils (Sarcophilus harrisii) could actually already hold the solution – natural antibodies found in the marsupial's immune system.

"Dr Beata Ujvari, from Deakin's Centre for Integrative Ecology within the School of Life and Environmental Sciences, investigated differences in molecules found in the devils' immune systems, comparing those that had the cancer, known as the Tasmanian Devil Facial Tumour Disease, and those that didn't.

"We know from human and animal studies that certain natural antibodies are able to recognise and kill cancerous cells, so we wanted to see whether the presence of these molecules would also determine tumour development in Tasmanian devils," Dr Ujvari said.

"'We found that devils that have a higher ratio of these natural antibodies were less likely to have cancer.

"'We can deduce then that devils with higher natural antibody ratio are therefore less susceptible to the contagious cancer.'"

Comment: Tis is an example of individual variability that is seen all through life, including the bacteria seen surviving the antibiotic experiment we have discussed.