Termites and intestinal flagellates relationship help

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

termites and intestinal flagellates relationship help

The termite protozoa do not pose any hazards to humans. mutual relationship with the termite where each organism benefits from the relationship. Cover the gut contents with a cover slip and place the slide on a microscope to observe the . In the lower termites, cellulose digestion depends on the intestinal protozoa and symbiotic relationships between the termite and its intestinal protozoa, first. Termites depend upon the microbes in their gut or digestive tract to digest the complex gut are often beneficial to both partners and so are called a mutualistic relationship. They aid in digestion of food and disposal of waste products.

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

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

This paper is an attempt to explore the foundations of that evolutionary transition. Among eusocial insects, the symbiosis with these gut flagellates is a feature unique to the Cryptocercus-termite lineage. Historically, the death of these flagellates at molt was thought to be a key factor associated with termite eusocial origins, e. Any hypothesis that ignores this termite specific life history characteristic, however, is unsatisfactory and serves to emphasize the current deep-seated bias in analyzing Isopteran eusocial origins in terms of hymenopteran attributes [ 4950 ].

A re-examination of this symbiotic relationship during host molt is overdue for two compelling reasons: Interdependence In both Cryptocercus and lower termites there are two levels of dependence. First, individuals rely on gut flagellates to metabolize and supplement their wood diet; and second, neonates in both taxa rely on their parents in incipient colonies of termites for vertical transfer of the symbionts. In termites alone, there is a third level of dependence: The dependence on gut flagellates to help metabolize their wood diet, combined with the periodic death of these symbionts precludes independent living in termites.

termites and intestinal flagellates relationship help

If the host-symbiont relationship in Cryptocercus is used as a model of the termite ancestral state, previously independent insects evolved interdependency. Up to the threshold when the protistans began dying during the termite molting cycle, eusociality in termites may have been reversible, but in interdependent organisms the fitness of one depends on the fitness of another, making cooperation the best strategy [ 52 ].

Misconceptions How the gut symbiosis is established in neonates of Cryptocercus and lower termites, and how the symbiotic bond between the host and its gut flagellates is either maintained, or broken and subsequently re-established during the host molting period are consistently misunderstood in current literature [ 51 ].

Methane gas is a major product and termites are a large source of methane in our atmosphere. Methane is a more potent greenhouse gas than carbon dioxide.

termites and intestinal flagellates relationship help

No one microbe in the termite gut can do the job. A whole community of microorganisms is necessary. 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. 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. 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.

Termites & Intestinal Flagellates by shanice anderson on Prezi

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. They cannot break down the wood by themselves.

termites and intestinal flagellates relationship help

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.