The satellitome of the beetle Chrysolina americana Linneo, 1758 has been characterized through chromosomal analysis, genomic sequencing, and bioinformatics tools. C-banding reveals the presence of constitutive heterochromatin blocks enriched in A+T content, primarily located in pericentromeric regions. Furthermore, a comprehensive satellitome analysis unveils the extensive diversity of satellite DNA families within the genome of C. americana. Using fluorescence in situ hybridization techniques and the innovative CHRISMAPP approach, we precisely map the localization of satDNA families on assembled chromosomes, providing insights into their organization and distribution patterns. Among the 165 identified satDNA families, only three of them exhibit a remarkable amplification and accumulation, forming large blocks predominantly in pericentromeric regions. In contrast, the remaining, less abundant satDNA families are dispersed throughout euchromatic regions, challenging the traditional association of satDNA with heterochromatin. Overall, our findings underscore the complexity of repetitive DNA elements in the genome of C. americana and emphasize the need for further exploration to elucidate their functional significance and evolutionary implications.

The genome of Triatoma delpontei Romaña & Abalos 1947 is the largest within Heteroptera, approximately two to three times greater than other evaluated Heteroptera genomes. Here, the repetitive fraction of the genome was determined and compared with its sister species Triatoma infestans Klug 1834, in order to shed light on the karyotypic and genomic evolution of these species. The T. delpontei repeatome analysis showed that the most abundant component in its genome is satellite DNA, which makes up more than half of the genome. The T. delpontei satellitome includes 160 satellite DNA families, most of them also present in T. infestans. In both species, only a few satellite DNA families are overrepresented on the genome. These families are the building blocks of the C-heterochromatic regions. Two of these satellite DNA families that form the heterochromatin are the same in both species. However, there are satellite DNA families highly amplified in the heterochromatin of one species that in the other species are in low abundance and located in the euchromatin. Therefore, the present results depicted the great impact of the satellite DNA sequences in the evolution of Triatominae genomes. Within this scenario, satellitome determination and analysis led to a hypothesis that explains how satDNA sequences have grown on T. delpontei to reach its huge genome size within true bugs.

Eukaryotic genomes exhibit a dynamic interplay between single-copy sequences and repetitive DNA elements, with satellite DNA (satDNA) representing a substantial portion, mainly situated at telomeric and centromeric chromosomal regions. We utilized Illumina next-generation sequencing data from Adalia bipunctata to investigate its satellitome. Cytogenetic mapping via fluorescence in situ hybridization was performed for the most abundant satDNA families. In silico localization of satDNAs was carried out using the CHRISMAPP (Chromosome In Silico Mapping) pipeline on the high-fidelity chromosome-level assembly already available for this species, enabling a meticulous characterization and localization of multiple satDNA families. Additionally, we analyzed the conservation of the satellitome at an interspecific scale. Specifically, we employed the CHRISMAPP pipeline to map the satDNAs of A. bipunctata onto the genome of Adalia decempunctata, which has also been sequenced and assembled at the chromosome level. This analysis, along with the creation of a synteny map between the two species, suggests a rapid turnover of centromeric satDNA between these species and the potential occurrence of chromosomal rearrangements, despite the considerable conservation of their satellitomes. Specific satDNA families in the sex chromosomes of both species suggest a role in sex chromosome differentiation. Our interspecific comparative study can provide a significant advance in the understanding of the repeat genome organization and evolution in beetles.

Repetitive DNA is a major component of eukaryotic genomes, playing structural, and evolutionary roles. However, in Neuroptera, its characterization remains unexplored. To address this, we analyzed the satellitomes of two Chrysopini (Chrysopidae) species using cytogenomic tools, also investigating telomeric and ribosomal DNA (rDNA). The canonical insect telomeric motif was absent, and rDNA clusters showed variation compared to other neuropterans, despite karyotype stasis (2n = 12, XY). Satellite DNA (satDNA) abundance varied between Ceraeochrysa cincta and Chrysopa pallens, representing a minor fraction of their repetitive DNA content. Notably, no satDNA sequences were shared between species, suggesting a rapid turnover. Exceptionally, the second-most abundant satDNA in each species showed low sequence similarity and a putative common origin. A relationship between satDNAs and transposable elements was also observed. Chromosome mapping revealed that abundant satDNAs accumulated in euchromatin, providing insights into their genomic distribution. These findings enhance our understanding of satDNA organization in Neuroptera, offering a foundation for future genome assembly efforts and evolutionary studies in these insects.

The genome of Triatoma rubrofasciata , a representative of the North American Triatomini lineage, was analysed to characterise its repetitive DNA content and satellite DNA (satDNA) organisation. Using RepeatExplorer2, we determined that repetitive elements comprise approximately 25% of the genome in a male sample from Vietnam and 16% in a female sample from China, with satDNA being the most abundant component. The satellitome analysis revealed 126 satDNA families in the male and 114 in the female, with marked quantitative differences driven by the amplification of two satDNA families: TrubSat001‐166 and TrubSat002‐9. Fluorescence in situ hybridization (FISH) confirmed that TrubSat002‐9 is enriched in the Y chromosome, explaining its lesser abundance in the female genome. Chromosomal mapping revealed three distribution patterns of satDNA: (i) localisation in autosomal heterochromatin, (ii) restriction to the Y chromosome, and (iii) presence in euchromatin. SatDNA landscapes showed sharp peaks at low divergence values, consistent with recent amplifications in heterochromatic regions, and broader peaks at higher divergence levels, suggesting older satDNAs located in euchromatic regions. Additionally, several satDNA families are conserved among T. rubrofasciata , T. infestans , T. delpontei and Rhodnius prolixus , supporting the “library hypothesis” of satDNA evolution. Our findings highlight the differential amplification of satDNA families linked to heterochromatin expansion, particularly in autosomes, and the conservation of Y‐linked repeats. This study provides new insights into the dynamic role of satDNAs in the karyotypic evolution of Triatominae bugs.