TAR30, a homolog of the canonical plant TTTAGGG telomeric repeat, is enriched in the proximal chromosome regions of peanut (Arachis hypogaea L.)

Gao, Dongying; Nascimento, Eliza F. M. B.; Leal‐Bertioli, Soraya C. M.; Jackson, Scott A.; Araújo, Ana Cláudia Guerra; Bertioli, David J.

doi:10.1007/s10577-022-09684-7

Cited by 5 publications

(2 citation statements)

References 63 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In addition, even both arms of the submetacentric neo‐Y chromosome were missing detectable telomeric arrays. The disproportionate accumulation of telomeric repeats on the short arms may be explained by the co‐amplification of the standard telomeric motif with other flanking repeats ( e.g ., Garrido‐Ramos et al ., 1998; Guzmán‐Markevich et al ., 2022) or the presence of the repeat motif with a monomer sequence highly similar to the true telomeric motif ( e.g ., Gao et al ., 2022).…”

Section: Discussionmentioning

confidence: 99%

Chromosomal rearrangements and the first indication of an ♀X₁X₁X₂X₂/♂X₁X₂Y sex chromosome system in Rineloricaria fishes (Teleostei: Siluriformes)

Marajó

Viana

Ferreira

et al. 2022

Journal of Fish Biology

View full text Add to dashboard Cite

Rineloricaria is the most diverse genus within the freshwater fish subfamily Loricariinae, and it is widely distributed in the Neotropical region. Despite limited cytogenetic data, records from southern and south‐eastern Brazil suggest a high rate of chromosomal rearrangements in this genus, mirrored in remarkable inter‐ and intraspecific karyotype variability. In the present work, we investigated the karyotype features of Rineloricaria teffeana, an endemic representative from northern Brazil, using both conventional and molecular cytogenetic techniques. We revealed different diploid chromosome numbers (2n) between sexes (33♂/34♀), which suggests the presence of an ♀X1X1X2X2/♂X1X2Y multiple sex chromosome system. The male‐limited Y chromosome was the largest and the only biarmed element in the karyotype, implying Y‐autosome fusion as the most probable mechanism behind its origination. C‐banding revealed low amounts of constitutive heterochromatin, mostly confined to the (peri)centromeric regions of most chromosomes (including the X2 and the Y) but also occupying the distal regions of a few chromosomal pairs. The chromosomal localization of the 18S ribosomal DNA (rDNA) clusters revealed a single site on chromosome pair 4, which was adjacent to the 5S rDNA cluster. Additional 5S rDNA loci were present on the autosome pair 8, X1 chromosome, and in the presumed fusion point on the Y chromosome. The probe for telomeric repeat motif (TTAGGG)n revealed signals of variable intensities at the ends of all chromosomes except for the Y chromosome, where no detectable signals were evidenced. Male‐to‐female comparative genomic hybridization revealed no sex‐specific or sex‐biased repetitive DNA accumulations, suggesting a presumably low level of neo‐Y chromosome differentiation. We provide evidence that rDNA sites might have played a role in the formation of this putative multiple sex chromosome system and that chromosome fusions originate through different mechanisms among different Rineloricaria species.

show abstract

Section: Discussionmentioning

confidence: 99%

Chromosomal rearrangements and the first indication of an ♀X₁X₁X₂X₂/♂X₁X₂Y sex chromosome system in Rineloricaria fishes (Teleostei: Siluriformes)

Marajó

Viana

Ferreira

et al. 2022

Journal of Fish Biology

View full text Add to dashboard Cite

show abstract

“…Moreover, highly dynamic ITR sites found outside pericentromeric positions in Anacyclus exhibit large inter-and even intra-species variability (Rosato et al, 2018). Telomeric repeats may also mutate and eventually evolve into satellite DNA at non telomeric positions (Mlinarec et al, 2009;Emadzade et al, 2014;Gao et al, 2022). These observations argue against Robertsonian fusions/rearrangements being a sole mechanism of ITR origins and alternative hypotheses were proposed: (i) The repair mechanisms of DNA double-strand breaks (Ruiz-Herrera et al, 2008).…”

Section: Introductionmentioning

confidence: 99%

Mega‐sized pericentromeric blocks of simple telomeric repeats and their variants reveal patterns of chromosome evolution in ancient Cycadales genomes

et al. 2022

View full text Add to dashboard Cite

Simple telomeric repeats composed of six to seven iterating nucleotide units are important sequences typically found at the ends of chromosomes. Here we analyzed their abundance and homogeneity in 42 gymnosperm (29 newly sequenced), 29 angiosperm (one newly sequenced), and eight bryophytes using bioinformatics, conventional cytogenetic and molecular biology approaches to explore their diversity across land plants. We found more than 10 000-fold variation in the amounts of telomeric repeats among the investigated taxa. Repeat abundance was positively correlated with increasing intragenomic sequence heterogeneity and occurrence at non-telomeric positions, but there was no correlation with genome size. The highest abundance/heterogeneity was found in the gymnosperm genus Cycas (Cycadaceae), in which megabase-sized blocks of telomeric repeats (i.e., billions of copies) were identified. Fluorescent in situ hybridization experiments using variant-specific probes revealed canonical Arabidopsis-type telomeric TTTAGGG repeats at chromosome ends, while pericentromeric blocks comprised at least four major telomeric variants with decreasing abundance: TTTAGGG>TTCAGGG >TTTAAGG>TTCAAGG. Such a diversity of repeats was not found in the sister cycad family Zamiaceae or in any other species analyzed. Using immunocytochemistry, we showed that the pericentromeric blocks of telomeric repeats overlapped with histone H3 serine 10 phosphorylation signals. We show that species of Cycas have amplified their telomeric repeats in centromeric and telomeric positions on telocentric chromosomes to extraordinary high levels. The ancestral chromosome number reconstruction suggests their occurrence is unlikely to be the product of ancient Robertsonian chromosome fusions. We speculate as to how the observed chromosome dynamics may be associated with the diversification of cycads.

show abstract

Haplotype-resolved chromosomal-level genome assembly of Buzhaye (Microcos paniculata)

Liu,

Tian,

Shao

et al. 2023

Sci Data

View full text Add to dashboard Cite

Microcos paniculata is a shrub used traditionally as folk medicine and to make herbal teas. Previous research into this species has mainly focused on its chemical composition and medicinal value. However, the lack of a reference genome limits the study of the molecular mechanisms of active compounds in this species. Here, we assembled a haplotype-resolved chromosome-level genome of M. paniculata based on PacBio HiFi and Hi-C data. The assembly contains two haploid genomes with sizes 399.43 Mb and 393.10 Mb, with contig N50 lengths of 43.44 Mb and 30.17 Mb, respectively. About 99.93% of the assembled sequences could be anchored to 18 pseudo-chromosomes. Additionally, a total of 482 Mb repeat sequences were identified, accounting for 60.76% of the genome. A total of 49,439 protein-coding genes were identified, of which 48,979 (99%) were functionally annotated. This haplotype-resolved chromosome-level assembly and annotation of M. paniculata will serve as a valuable resource for investigating the biosynthesis and genetic basis of active compounds in this species, as well as advancing evolutionary phylogenomic studies in Malvales.

show abstract

TAR30, a homolog of the canonical plant TTTAGGG telomeric repeat, is enriched in the proximal chromosome regions of peanut (Arachis hypogaea L.)

Cited by 5 publications

References 63 publications

Chromosomal rearrangements and the first indication of an ♀X₁X₁X₂X₂/♂X₁X₂Y sex chromosome system in Rineloricaria fishes (Teleostei: Siluriformes)

Chromosomal rearrangements and the first indication of an ♀X₁X₁X₂X₂/♂X₁X₂Y sex chromosome system in Rineloricaria fishes (Teleostei: Siluriformes)

Mega‐sized pericentromeric blocks of simple telomeric repeats and their variants reveal patterns of chromosome evolution in ancient Cycadales genomes

Haplotype-resolved chromosomal-level genome assembly of Buzhaye (Microcos paniculata)

Contact Info

Product

Resources

About

TAR30, a homolog of the canonical plant TTTAGGG telomeric repeat, is enriched in the proximal chromosome regions of peanut (Arachis hypogaea L.)

Cited by 5 publications

References 63 publications

Chromosomal rearrangements and the first indication of an ♀X1X1X2X2/♂X1X2Y sex chromosome system in Rineloricaria fishes (Teleostei: Siluriformes)

Chromosomal rearrangements and the first indication of an ♀X1X1X2X2/♂X1X2Y sex chromosome system in Rineloricaria fishes (Teleostei: Siluriformes)

Mega‐sized pericentromeric blocks of simple telomeric repeats and their variants reveal patterns of chromosome evolution in ancient Cycadales genomes

Haplotype-resolved chromosomal-level genome assembly of Buzhaye (Microcos paniculata)

Contact Info

Product

Resources

About

Chromosomal rearrangements and the first indication of an ♀X₁X₁X₂X₂/♂X₁X₂Y sex chromosome system in Rineloricaria fishes (Teleostei: Siluriformes)

Chromosomal rearrangements and the first indication of an ♀X₁X₁X₂X₂/♂X₁X₂Y sex chromosome system in Rineloricaria fishes (Teleostei: Siluriformes)