What do genomic islands do?

Genomic islands are region of laterally-acquired large DNA sequences (10–200kb) which encode accessory genes that can equip the harboring bacteria with improved fitness, virulence, metabolic flexibility etc.

How are genomic islands identified?

Genomic islands (GEIs) are characterized by their large size (>10 kb), their frequent association with tRNA-encoding genes and a different G+C content compared with the rest of the chromosome.

What is genome divergence?

Genetic divergence is the process in which two or more populations of an ancestral species accumulate independent genetic changes (mutations) through time, often leading to reproductive isolation and continued mutation even after the populations have become reproductively isolated for some period of time, as there isn’ …

What is speciation with gene flow?

When a single population separates into two distinct species, different components of reproductive isolation must be coupled together. For example, genes that cause assortative mating must become associated with genes that are adapted to exploit different ecological resources.

What is meant by a pathogenicity island?

Pathogenicity island: The genetic element, the “island of evil”, within the genome of an organism that is responsible for its capacity to cause disease (its pathogenicity). The virulence of the organism is modulated by genes harbored on this island.

What is the difference between core and pan genome?

The core-genome is the set of homologous genes that are present in all genomes of an analyzed dataset and the pan-genome is the set of all genes that are present in the analyzed dataset [16].

What are the different types of genes called?

Different versions of a gene are called alleles. Alleles are described as either dominant or recessive depending on their associated traits.

What are genomic islands of divergence?

Genomic islands of speciation (also known as genomic islands of divergence) are the parts of the genome that underlie this reproductive isolation or adaptation and are resistant to the homogenizing effects of gene flow.

What is the role of gene flow in speciation?

For this reason, gene flow has been thought to constrain speciation and prevent range expansion by combining the gene pools of the groups, thus preventing the development of differences in genetic variation that would have led to differentiation and adaption.

What is the function of pathogenicity islands?

Pathogenicity islands carry genes encoding one or more virulence factors, including, but not limited to, adhesins, toxins, or invasins. They may be located on a bacterial chromosome or may be transferred within a plasmid.