The bacteria convince their squid hosts to create a less harsh working environment

A new study by researchers at the University of Hawaii's School of Marine and Earth Sciences and Technology suggests that bacteria that symbiotically grow in the Hawaiian short-tailed squid can guide the host squid to alter its normal gene expression routine to create a more enticing home.

Almost every organism and environment has a symbiotic group of microbes — a kind of microbe — that are an integral part of ecosystems and human health. In bacteria, small RNA (sRNA) is a key factor influencing gene expression in microbes, however, there is little evidence that beneficial bacteria use these molecules to communicate with their animal hosts.

In the new study, author Sylvia Moriano-Gutierrez, a postdoc at the Pacific Center for Biological Sciences, and her colleagues found that specific bacterial sRNAs are typically responsible for quality control of the bacteria's protein production play an important role among Vibrio phylogenes and squid.

Hawaiian short-tailed squid utilizes V. Fischeri parasitizes in the squid's light organs because the bacteria emit light and can camouflage it when the squid hunts at night.

With RNA sequencing, the scientists found sRNA sequences produced by bacteria parasitic in light organs in the blood of squid, and high concentrations of specific sRNAs in host cells within the crypts where the bacteria live.

Dr. Moriano Gutierrez said: "The presence of this particular sRNA will 'calm' the squid's immune response, which will increase the chances that bacteria will continue to settle on the host tissue and play their beneficial role." "This work reveals that sRNAs of bacterial symbiotes can not only control their own activities, but also trigger critical responses that promote peaceful cooperation with hosts."

The researchers, including the authors and Mā Noah's family Leo Wu, determined that the bacteria loaded the sRNA into their outer membrane vesicles, transported to the symbiotic organism population around the cell according to the organ-decreasing antibacterial activity of the squid in the appropriate place.

Dr. Moriano Gutierrez said: "Surprisingly, at the beginning of the symbiotic relationship, a common bacterial sRNA was specifically recruited into the bacteria's communication with the host, and this sRNA evolved a housekeeping function in bacteria."

Dr. Moriano Gutierrez said: "We expect that host recognition and response to specific sRNAs symbiotes will become the main new mode of communication between bacteria and the animal tissues they inhabit." "Other symbionts RNA that enter host cells remain to be studied."