Open AccessCenH3 distribution reveals extended centromeres in the model beetle Tribolium castaneum
Author(s) -
Tena Gržan,
Evelin Despot-Slade,
Nevenka Meštrović,
Miroslav Plohl,
Brankica Mravinac
Publication year - 2020
Publication title -
plos genetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.587
H-Index - 233
eISSN - 1553-7404
pISSN - 1553-7390
DOI - 10.1371/journal.pgen.1009115
Subject(s) - centromere , biology , kinetochore , genetics , chromosome , histone h3 , karyotype , chromatin , heterochromatin , evolutionary biology , dna , gene
Centromeres are chromosomal domains essential for kinetochore assembly and correct chromosome segregation. Inconsistent in their underlying DNA sequences, centromeres are defined epigenetically by the presence of the centromere-specific histone H3 variant CenH3. Most of the analyzed eukaryotes have monocentric chromosomes in which CenH3 proteins deposit into a single, primary constriction visible at metaphase chromosomes. Contrary to monocentrics, evolutionary sporadic holocentric chromosomes lack a primary constriction and have kinetochore activity distributed along the entire chromosome length. In this work, we identified cCENH3 protein, the centromeric H3 histone of the coleopteran model beetle Tribolium castaneum . By ChIP-seq analysis we disclosed that cCENH3 chromatin assembles upon a repertoire of repetitive DNAs. cCENH3 in situ mapping revealed unusually elongated T . castaneum centromeres that comprise approximately 40% of the chromosome length. Being the longest insect regional centromeres evidenced so far, T . castaneum centromeres are characterized by metapolycentric structure composed of several individual cCENH3-containing domains. We suggest that the model beetle T . castaneum with its metapolycentromeres could represent an excellent model for further studies of non-canonical centromeres in insects.