Repeat-based holocentromeres of the woodrush Luzula sylvatica reveal insights into the evolutionary transition to holocentricity

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: Nov. 5, 2024

Abstract In most studied eukaryotes, chromosomes are monocentric, with centromere activity confined to a single region. However, the rush family (Juncaceae) includes species both monocentric ( Juncus ) and holocentric Luzula chromosomes, where is distributed along entire chromosome length. Here, we combine chromosome-scale genome assembly, epigenetic analysis, immuno-FISH super-resolution microscopy study transition holocentricity in sylvatica . We report repeat-based holocentromeres an irregular distribution of features chromosomes. predominantly associated two satellite DNA repeats Lusy1 Lusy2 ), while CENH3 also binds satellite-free gene-poor regions. Comparative repeat analysis suggests that plays crucial role function across species. Furthermore, synteny between L. n = 6) effusus 21) could have arisen from fusions ancestral accompanied by expansion CENH3-associated repeats.

Language: Английский

Repeat-based holocentromeres of the woodrush Luzula sylvatica reveal new insights into the evolutionary transition from mono- to holocentricity

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: April 10, 2024

Abstract Although the centromere is restricted to a single region of chromosome in most studied eukaryotes, members rush family (Juncaceae) harbor either monocentric ( Juncus) or holocentric Luzula ) chromosomes. This provides an opportunity study evolutionary mechanisms involved transition holocentricity. Here by combining chromosome-scale genome assembly, epigenetic analyses, immuno-FISH, and super-resolution microscopy, we report occurrence repeat-based holocentromeres L. sylvatica . We found irregular distribution genes, centromeric units, repeats along determined function predominantly associated with two satellite DNA repeats, Lusy1 Lusy2 124– 174-bp monomer length, respectively, while CENH3 also binds satellite-free gene-poor regions. Comparative repeat analysis revealed that present species, suggesting conserved role this repeat. Synteny between n = 6) J. effusus 21) genomes further evidenced number reduction derived from multiple fusions ancestral -like propose holocentricity involves: (i) fusion small chromosomes resembling Juncus centromeres; (ii) expansion atypical units; (iii) colonization for stabilization.

Language: Английский

Distinct patterns of satDNA distribution in spike-sedges (Eleocharis, Cyperaceae): evidence of repeat-based holocentromeres

Research Square (Research Square), Journal Year: 2024, Volume and Issue: unknown

Published: April 19, 2024

Eleocharis R. Br. (Cyperaceae) species are known for having holocentric chromosomes, which enable rapid karyotype differentiation. Indeed, high intra- and interspecific variations in chromosome numbers genome sizes documented different species, frequently accompanied by fluctuations the repetitive DNA fraction. However, a lack of detailed analysis has hampered better understanding interplay between holocentricity evolution genus. In this study, we confirmed chromosomes immunostaining against KNL1, histone H2AThr121ph H3S10ph. We further studied composition chromosomal distribution main satellite repeats found five newly sequenced species. Five six satellites discovered were arranged clusters, while EmaSAT14 was dispersed irregularly along chromatid length line-like manner. This satDNA accumulated exclusively belonging to series Maculosae subgenus Eleocharis. The genomic organization suggest that it is potential holocentromeric repeat. Our findings repeat-based holocentromeres likely evolve similar way across plants.

Language: Английский