A bacteriome is a specialized organ, found mainly in some insect

Insect

Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...

s, that hosts endosymbiotic bacteria

Bacteria

Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...

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Bacteriomes contain specialized cells, called bacteriocytes

Bacteriocyte

A bacteriocyte , also called a mycetocyte, is a specialized adipocyte found in some insect groups such as aphids, tsetse flies, german cockroaches, and many others. Mycetocyte symbionts specifically include three insect groups: Cockroaches, Homoptera such as aphid, and Coleoptera such as weevils...

, that provide nutrients and shelter to the bacteria while protecting the host animal.
In exchange, the bacteria provide essentials like vitamins and amino acid

Amino acid

Amino acids are molecules containing an amine group, a carboxylic acid group and a side-chain that varies between different amino acids. The key elements of an amino acid are carbon, hydrogen, oxygen, and nitrogen...

s to the host insect.

Some insects, like the glassy-winged sharpshooter

Glassy-winged sharpshooter

The glassy-winged sharpshooter is a large leafhopper insect from the family Cicadellidae, similar to other species of sharpshooter.-Description:These sharpshooters are about in length...

, host more than one species of bacteria

Bacteria

Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...

. In armored scale insects, bacteriomes have unique genetic

Genetics

Genetics , a discipline of biology, is the science of genes, heredity, and variation in living organisms....

 and sexual properties.
For example, they have five copies of each chromosome

Chromosome

A chromosome is an organized structure of DNA and protein found in cells. It is a single piece of coiled DNA containing many genes, regulatory elements and other nucleotide sequences. Chromosomes also contain DNA-bound proteins, which serve to package the DNA and control its functions.Chromosomes...

 -- including two copies of the mother's complete genome

Genome

In modern molecular biology and genetics, the genome is the entirety of an organism's hereditary information. It is encoded either in DNA or, for many types of virus, in RNA. The genome includes both the genes and the non-coding sequences of the DNA/RNA....

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