Distribution of CRISPR-Cas systems in the Burkholderiaceae family and its biological implications.

CRISPR-Cas systems are composed of repeated sequences separated by non-repeated sequences that are near genes coding for Cas proteins, which are involved in the function of these systems. Their function has been mostly related to "genetic immunity" against foreign genetic material, among other roles. Interest in them increased after their use in genetic manipulation was uncovered and surveys to find and classify them have been done in several bacterial groups.