MOSCOW, July 8. /TASS/. Scientists from Institute for Information Transmission Problems of the (IITP) and other Russian institutes have decoded the complete genome of orthonectida Intoshia linei, a parasite of marine invertebrates, with the nervous systems consisting only of 40 cells.
The study will help to establish the "minimal gene set" needed for functioning nervous system, IITP said.
Who are orthonectids?
Orthonectids are the parasites of marine invertebrates. They live inside their hosts as a multicore cell and bring into the world worm-shaped male and female descendants comprising of several hundreds of cells and free of the digestive, circulation, and eliminative systems. In the 19th century, when these creatures were discovered for the first time, they supposed to be an intermediary between single-and multicellular organisms. Now, the new data points out that this group has been simplified during the evolution process due to the parasitic mode of life.
This hypothesis on the reasons of extreme simplicity of orthonectids is also confirmed by the new study of Russian scientists from IITP, Moscow State University, and Saint-Petersburg State University recently published in the journal Current Biology.
On the survival minimum
According to IITP, the entire genome of Intoshia linei has also appeared to be quite simple: it contains about 9,000 genes. For comparison, a threadworm Caenorhabditis elegans, a creature with one of the simplest nervous system, has a genome with about 20,000 genes.
The rest of genes needed for the functioning of the nervous system and other processes have been lost by orthonectids as a result of adaptation to the parasitic mode of life. Therefore, the genome of Intoshia linei can be considered as the "minimal gene set" for keeping all main features of bilateral (two-sided) animals with functioning nervous system.
In the beginning of 2016 American scientists have edited the gene of bacteria Mycoplasma mycoides to the minimal set of 473 genes.