Evolutionary Formation of New Centromeres in Macaque

Abstract

A systematic fluorescence in situ hybridization comparison of macaque and human synteny organization disclosed five additional macaque evolutionary new centromeres (ENCs) for a total of nine ENCs. To understand the dynamics of ENC formation and progression, we compared the ENC of macaque chromosome 4 with the human orthologous region, at 6q24.3, that conserves the ancestral genomic organization. A 250-kilobase segment was extensively duplicated around the macaque centromere. These duplications were strictly intrachromosomal. Our results suggest that novel centromeres may trigger only local duplication activity and that the absence of genes in the seeding region may have been important in ENC maintenance and progression.

Centromere repositioning in cucurbit species: Implication of the genomic impact from centromere activation and inactivation

“…Segmental duplication is a prominent feature associated with the pericentromeric regions of most human chromosomes (33). However, there has been limited evidence indicating that centromere re-seeding may trigger formation of such segmental duplications (14). Similar segmental duplications were not found in the pericentromeric regions of several well sequenced model plant species, including rice and Arabidopsis thaliana.…”

“…Although CRs occurred frequently in the evolution of mammalian species and was implicated to play an important role in mammalian genome evolution (14), very little is known about the genomic consequences of re-seeding a centromere in an eukaryotic chromosome. Segmental duplication is a prominent feature associated with the pericentromeric regions of most human chromosomes (33).…”

“…Thus, neocentromeres do not seem to have any evolutionary advantage over existing native centromeres. However, comparative mapping among closely related mammalian species has revealed position changes of some centromeres during evolution, most likely via neocentromere formation (5,(10)(11)(12)(13)(14)(15). Centromere repositioning (CR) events have occurred frequently in some mammalian lineages.…”

Rapid Evolution of Yeast Centromeres in the Absence of Drive

“…Rapid centromere evolution has also been observed in some plants and animals (Haaf and Willard 1997;Henikoff et al 2001;Lee et al 2005;Ma et al 2007;Ventura et al 2007). In these taxa centromeres are extremely long and complex stretches of highly repetitive AT-rich satellite DNA, usually surrounded by or embedded in heterochromatin (Clarke 1998;Henikoff et al 2001;Sullivan et al 2001).…”

Fast Diploidization in Close Mesopolyploid Relatives ofArabidopsis

“…The centromere inactivation will ensure regular meiotic segregation of the fusion chromosome and can result in evolutionary fixed reduction of chromosome number. Several cases of inactivated ancestral centromeres as well as the emergence of neocentromeres (centromere repositioning) were reported in mammalian species (e.g., Ferreri et al, 2005;Ventura et al, 2007), but only a few examples of centromere inactivation (and reactivation; F. ) in plants, including dicentric chromosomes of Trititiceae (Sears and Camara, 1952;Luo et al, 2009), maize (Zea mays) B chromosomes (F. Han et al, 2006, and potentially also chromosomes of two cucurbit species (Y. . Except for the heterochromatic knob on chromosome SN3 corresponding to the AK5 centromere, no heterochromatin was observed at sites of the other 17 presumably inactivated centromeres.…”