Termites and intestinal flagellates relationship

Group Protozoa, Phylum Zoomastigina

termites and intestinal flagellates relationship

The mutualistic beneficial relationship of termites with intestinal symbionts . Flagellates have been described in the hindgut of workers of R. Many flagellates live within the gut of termites in a symbiotic relationship. The flagellates digest the cellulose in the cell walls of the wood ingested by the termites. they have a symbiotic relationship with one another referred to as mutualism.

Nearly distinct flagellate species have been described in the termite and Cryptocercus hosts that have been investigated see [ 78 ] for a catalogue of those reported. The morphological characters historically used to classify species, however, are proving in many cases to be inadequate, and new species and relationships are continually being described based on molecular sequencing techniques, e.

Termite symbiosis: Internal guests digest cellulose

The flagellates of the two host insect groups have similar taxonomic affiliations, and their distributions are either limited, or they cannot be found in other hosts or in the free-living state [ 2814 ]. Intergenerational transmission is vertical [ 1819 ]: In both taxa, the parents are the source of all flagellates for a given social group.

In termites, however, the flagellates are re-circulated among colony members via trophallaxis once the colony becomes established. As expected in vertically transmitted symbionts, flagellate communities of different host lineages indicate co-speciation, with possible horizontal shifts due to stochastic, dietary or ecological effects [ 20212223 ].

termites and intestinal flagellates relationship

Functionally, the gut microbiota partner with the host and each other to interactively degrade plant polymers, fix atmospheric nitrogen, synthesize amino acids, and recycle nitrogenous waste products [ 242526 ]. Further prokaryotes live free in the gut fluid or are attached to the gut wall of the insect host [ 2730313233343536373839 ].

That being said, the focus here is on the flagellates, which not only drive cellulose degradation [ 4041 ], but also are more exacting in their requirements than prokaryotes [ 42 ]. Recently, significant advances have been made in the understanding of these host-symbiont relationships, prompted by the application of new, sophisticated technologies that are independent of microbial culturing. Well over primary articles and reviews that address termite symbioses were published in the period —, inclusive [ 8 ].

Emphasis has been primarily on identification of the components of the microbiota in a phylogenetic context, and of individual biochemical functionality and interdependence.

Termite gut microbes | NOLL LAB

Our increased understanding of the sophistication of the microbiome, however, is not matched by an understanding of how it is integrated into the biology, behavior and life history of the insect host. The environment in which the flagellates live is unusually homeostatic and closely comparable from host to host [ 43 ].

The protists are housed in the gut of an individual insect, living within a family Cryptocercus or colony termiteswhich is lodged within the buffered environment of a nest. They are supplied with a steady stream of food, in a liquid, temperature-controlled, safe haven. Their world, then, is fairly constant, with one notable exception: If the relationship of these two insect taxa to their gut fauna during developmental ontogeny is compared, it is obvious that there has been an evolutionary change during the host molting cycle.

In both Cryptocercus and lower termites, neonates acquire the flagellates from a parent or a sibling the latter in established colonies of termites ; the symbiosis is established at about the third instar in both taxa.

The big difference lies in what subsequently occurs during the molting cycles of the developing juvenile host. After the symbiosis is established in Cryptocercus, it is retained through all subsequent ecdyses; it is never lost under natural conditions [ 154445 ].

Developing nymphs of this cockroach are thereafter nutritionally autonomous and capable of a solitary lifestyle. In termites, however, the large flagellates die prior to subsequent ecdyses and must be re-acquired by feeding on the hindgut fluids of a nest mate. Unlike most vertically transmitted symbioses [ 46 ] then, developing termites have an aposymbiotic phase with respect to the larger gut flagellates.

If cockroaches in the genus Cryptocercus are used as a model of the termite ancestral state, that shift in the host-symbiont relationship can be pinned to a specific node of the Dictyopteran phylogenetic tree.

These microbes belong to three groups, bacteriaarchaea and protozoans. Organisms that live with one another for long periods of time are said to live in symbiosis. The symbioses in the termite gut are often beneficial to both partners and so are called a mutualistic relationship.

What Kills the Hindgut Flagellates of Lower Termites during the Host Molting Cycle?

Sometimes neither partner can live without the other, so the relationship is called an obligate symbiosis. The protozoans and the bacteria and archeae that live insided them often depend upon one another and cannot live without each other, so they are an example of an obligate symbiosis. The bacteria and archaea that live inside their partner are also called endosymbionts"endo-" meaning "within.

termites and intestinal flagellates relationship

Bacteria and archaea are about a ten times smaller and appear as small specks in these photos. None of these organisms have a color and are largely transparent.

To photograph them without using dyes to stain them which would kill them we used a special kind of microscope that uses Nomarski optics to distinguish the microbes from the surrounding water. This gives three-dimensional images of the microbes. Photos courtesy of Dan Gage The protozoans come in a variety of shapes and move around rapidly.

These are their flagella that they use to move. They consume wood particles through the larger end of the cell.

termites and intestinal flagellates relationship

They cannot break down the wood by themselves. They harbor bacteria inside them that do this for them and some of the chemical products that those bacteria produce are used as food by. This is an example of a symbiosis or "living together". Personympha vertens or maybe Personympha minor? You be the judge.

termites and intestinal flagellates relationship

Microjoenia Holomastigotes elongatum Many of the bacteria in the termite gut live closely associated with the protozoans, sometimes on their surface or inside the protozoan cells.