''Sodalis'' is a genus of bacteria within the family

Pectobacteriaceae The ''Pectobacteriaceae'' are a family (biology), family of Gram-negative bacteria which largely consist of plant pathogens. This family is a member of the order Enterobacterales in the class Gammaproteobacteria of the phylum Pseudomonadota. The ...

. This genus contains several insect endosymbionts and also a free-living group. It is studied due to its potential use in the biological control of the

tsetse fly Tsetse ( , or ) (sometimes spelled tzetze; also known as tik-tik flies) are large, biting flies that inhabit much of tropical Africa. Tsetse flies include all the species in the genus ''Glossina'', which are placed in their own family, Gloss ...

. ''Sodalis'' is an important model for evolutionary biologists because of its nascent endosymbiosis with insects.

Occurrence and ecological significance

''Sodalis'' was described in louse fly ('' Craterina melbae''), in stinkbug (

Cantao ocellatus ''Cantao ocellatus'' is a species of shield bug in the family Scutelleridae found across Asia. Description ''Cantao ocellatus'' is reddish or ochre in overall colour it has dark legs and bluish black antennae. A dark bluish black stripe is p ...

) in

Louse Louse (: lice) is the common name for any member of the infraorder Phthiraptera, which contains nearly 5,000 species of wingless parasitic insects. Phthiraptera was previously recognized as an order (biology), order, until a 2021 genetic stud ...

(''Columbicola columbae'') and in other ectoparasites of water mammals (like ''Proechinophthirus fluctus,

)''. Species ''Candidatus Sodalis melophagi'' was described in sheep ked (''

Melophagus ovinus ''Melophagus ovinus'', or the sheep ked, is a brown, hairy fly that resembles a tick. This wingless fly is about 4 to 6 mm long and has a small head; it is a fly from the family Hippoboscidae. They are blood-feeding parasites of sheep. The ...

''). Another species ''Candidatus Sodalis pierantonius'' str. SOPE is known as endosymbiont of rice weevil (''

Sitophilus oryzae The rice weevil (''Sitophilus oryzae'') is a stored product pest which attacks seeds of several crops, including wheat, rice, and maize. Description The adults are usually between long, with a long snout. The body color appears to be brown/bla ...

'') and can supply rice weevil with essential vitamins like pantothenic acid, riboflavin, and biotin. A species of bacteria within this genera, '' Sodalis glossinidius'', was found in the

hemolymph Hemolymph, or haemolymph, is a fluid, similar to the blood in invertebrates, that circulates in the inside of the arthropod's body, remaining in direct contact with the animal's tissues. It is composed of a fluid plasma in which hemolymph c ...

of the

(''Glossina morsitans''). This bacteria has been used in

paratransgenesis Paratransgenesis is a technique that attempts to eliminate a pathogen from Vector (epidemiology), vector populations through transgenesis of a symbiont of the vector. The goal of this technique is to control vector-borne diseases. The first step is ...

approaches to fight sleeping sickness. Genome analysis shows that symbiosis between '' Sodalis glossinidius'' and tsetse fly is evolutionary young. ''Sodalis'' has large genome and pseudogenes which remain, however, active in cell-free culture. Fly cleared from its native symbionts can be successfully repopulated by ''Sodalis'' from other fly species. This might be used in potential biological control of

Free-living species

The ''Sodalis'' bacterium has also been identified as free-living with no association to insects. ''Sodalis praecaptivus'', was isolated from a hand injured by a tree branch. ''Sodalis ligni'' was found to be widely associated with decomposing wood of various tree species. ''S. ligni'', unlike other ''Sodalis'' species, contains

nitrogen fixation Nitrogen fixation is a chemical process by which molecular dinitrogen () is converted into ammonia (). It occurs both biologically and abiological nitrogen fixation, abiologically in chemical industry, chemical industries. Biological nitrogen ...

genes. Such ecological trait might be important for other saprotrophs living in deadwood as this habitat is nitrogen-limited. Compared to endosymbionts, free-living ''Sodalis'' species are characterized by larger

genomes A genome is all the genetic information of an organism. It consists of nucleotide sequences of DNA (or RNA in RNA viruses). The nuclear genome includes protein-coding genes and non-coding genes, other functional regions of the genome such as ...

, longer

genes In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei ...

, and fewer

pseudogenes Pseudogenes are nonfunctional segments of DNA that resemble functional genes. Pseudogenes can be formed from both protein-coding genes and non-coding genes. In the case of protein-coding genes, most pseudogenes arise as superfluous copies of fun ...

. These characteristics point to asymbiotic lifestyle of these species. Due to known free-living species and related endosymbionts with evolutionarily young link to insect, the whole genus is important for studies about development of the insect endosymbiosis.

References

External links

NCBI Taxonomy
{{Taxonbar, from=Q16992604 Pectobacteriaceae Bacteria genera