This page contains the current definition, format and controlled vocabularly for repeat type qualifier.
The page has been created on Ocober 9, 2013. Last updated October 2015.
Definition: organization of repeated sequence
Value format: tandem, inverted, flanking, terminal, direct, dispersed, and other
Comment: the values are case-insensitive, i.e. both “INVERTED” and “inverted” are valid;
Definitions of the values:
tandem: a repeat that consists of two or more adjacent copies of a region whose length is greater than one in the same orientation;
inverted: a repeat pair occurring in reverse orientation to one another on the same molecule;
flanking: a repeat lying outside the sequence for which it has functional significance (eg. transposon insertion target sites);
terminal: a repeat at the ends of and within the sequence for which it has functional significance other than long terminal repeat;
direct: a repeat where the same sequence is repeated in the same direction;
dispersed: a repeat that is located at dispersed sites in the genome;
nested: a repeat that is disrupted by the insertion of another element;
long_terminal_repeat: a sequence directly repeated at both ends of a defined sequence, of the sort typically found in retroviruses (replaces LTR Feature Key);
non_ltr_retrotransposon_polymeric_tract: a polymeric tract, such as poly(dA), within a non LTR retrotransposon;
x_element_combinatorial_repeat: a repeat region located between the X element and the telomere or adjacent Y’ element;
y_prime_element: a repeat region located adjacent to telomeric repeats or X element combinatorial repeats, either as a single copy or tandem repeat of two to four copies;
telomeric_repeat: a repeat region found within the telomere;
centromeric_repeat: a repeat region found within the modular centromere;
other: a repeat exhibiting important attributes that cannot be described by other values.
Note: terms in italics are going to be supported from December 2015.