TY - JOUR

T1 - Divergence and conservation of satellite DNA in the loggerhead sea turtle (Caretta caretta): a comparative cytogenomic analysis

AU - Tishakova, Katerina V.

AU - Proskuryakova, Anastasia A.

AU - Prokopov, Dmitry Yu

AU - Marchenko, Sergey A.

AU - Iannucci, Alessio

AU - Ciofi, Claudio

AU - Tolve, Livia

AU - Casale, Paolo

AU - Salvemini, Pasquale

AU - Serdyukova, Natalia A.

AU - Davletshina, Guzel I.

AU - Trifonov, Vladimir A.

AU - Romanenko, Svetlana A.

N1 - Tishakova, K.V., Proskuryakova, A.A., Prokopov, D.Y. et al. Divergence and conservation of satellite DNA in the loggerhead sea turtle (Caretta caretta): a comparative cytogenomic analysis. Chromosome Res 34, 3 (2026). https://doi.org/10.1007/s10577-026-09794-6 This research was funded by Russian Science Foundation grant No 25–24-00171 (KVT).

PY - 2026/2/23

Y1 - 2026/2/23

N2 - Repetitive DNA sequences, particularly satellite DNA (satDNA), are key components of eukaryotic genomes with important structural and potential functional roles. In this study, we used long-read assemblies and short-read sequencing to perform de novo identification of the most abundant satDNAs in the sea turtle Caretta caretta. We combined a bioinformatic approach and chromosome mapping to describe the distribution of the major tandem repetitive DNA sequences of this species. Additionally, we mapped major ribosomal DNA clusters, telomeric sequences and performed Chromomycin A3-DAPI-after G-banding (CDAG) staining to visualise AT-/GC-rich chromatin composition. We found that the C. caretta satellitome contains at least 18 satDNAs. Most of the satDNAs are localised in pericentromeric regions of chromosomes. We observed a differential, non-uniform distribution of repetitive DNA sequences between chromosomes: while most chromosomes carry blocks consisting of a single chromosome-specific satellite, some chromosomes contain complex heterochromatic blocks composed of multiple satellites. Comparative analysis showed inconsistencies between in situ and in silico satDNA mapping. These new data add to the knowledge about the diversity, distribution, and evolution of satDNA in the C. caretta genome.

AB - Repetitive DNA sequences, particularly satellite DNA (satDNA), are key components of eukaryotic genomes with important structural and potential functional roles. In this study, we used long-read assemblies and short-read sequencing to perform de novo identification of the most abundant satDNAs in the sea turtle Caretta caretta. We combined a bioinformatic approach and chromosome mapping to describe the distribution of the major tandem repetitive DNA sequences of this species. Additionally, we mapped major ribosomal DNA clusters, telomeric sequences and performed Chromomycin A3-DAPI-after G-banding (CDAG) staining to visualise AT-/GC-rich chromatin composition. We found that the C. caretta satellitome contains at least 18 satDNAs. Most of the satDNAs are localised in pericentromeric regions of chromosomes. We observed a differential, non-uniform distribution of repetitive DNA sequences between chromosomes: while most chromosomes carry blocks consisting of a single chromosome-specific satellite, some chromosomes contain complex heterochromatic blocks composed of multiple satellites. Comparative analysis showed inconsistencies between in situ and in silico satDNA mapping. These new data add to the knowledge about the diversity, distribution, and evolution of satDNA in the C. caretta genome.

KW - Assembly

KW - FISH

KW - Repeats

KW - Reptilia

KW - Testudines

UR - https://www.scopus.com/pages/publications/105030690982

UR - https://www.mendeley.com/catalogue/732e3678-b954-3c7a-a35a-5a72d45d7f35/

U2 - 10.1007/s10577-026-09794-6

DO - 10.1007/s10577-026-09794-6

M3 - Article

C2 - 41729402

VL - 34

JO - Chromosome Research

JF - Chromosome Research

SN - 0967-3849

IS - 1

M1 - 3

ER -