Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2025 Sep 10.
doi: 10.1007/s00709-025-02109-2. Online ahead of print.

Chromosomal puzzle in snakes: adjacent interstitial telomeric sites on chromosome 5 in three species of genus Vipera

Ilya Redekop  1 , Victor Spangenberg  2   3
Affiliations

Chromosomal puzzle in snakes: adjacent interstitial telomeric sites on chromosome 5 in three species of genus Vipera

Ilya Redekop et al. Protoplasma. .

Abstract

Large interstitial telomeric regions are considered remnants and markers of chromosomal rearrangements or a result of several suggested molecular mechanisms of telomere repeats accumulation. More rare are cases when large interstitial repeats are found not close to, but at a distance from the centromere. However, synapsis, recombination, and effects on chromatin near these regions during meiotic prophase I have not been sufficiently studied. Using the model of three snake species of the genus Vipera: V. berus, V. nikolskii, V. renardi, we studied interstitial telomere sites (ITSs) in the pachytene nuclei of primary spermatocytes. We discovered an unusual composite chromosome in the species under study with two ITSs located far from the centromere. In V. berus, two very large adjacent ITS blocks were found on bivalent 5. In the other two species, V. nikolskii and V. renardi, two ITSs are also present on bivalent 5, but they are significantly smaller and barely distinguishable by FISH on pachytene bivalents. The possibility of forming crossing-over sites is shown between the two ITSs. Apparently, the three studied viper species received this complex structure of chromosome 5 from their common ancestor. However, the transformation of these telomeric repeat regions during evolution in the species under study occurred differently. Possible mechanisms of modifications of the telomeric regions are discussed.

Keywords: Centromere; Interstitial telomere sites; Meiosis; Recombination hot spot; Synaptonemal complex; Telomere.

PubMed Disclaimer

Conflict of interest statement

Declarations. Conflict of interest: The authors declare no competing interests.

References

    1. Ahmad SF, Singchat W, Jehangir M, Panthum T, Srikulnath K (2020) Consequence of paradigm shift with repeat landscapes in reptiles: powerful facilitators of chromosomal rearrangements for diversity and evolution. Genes 11(7):827. https://doi.org/10.3390/genes11070827 - DOI - PubMed - PMC
    1. Aksenova AY, Mirkin SM (2019) At the beginning of the end and in the middle of the beginning: structure and maintenance of telomeric DNA repeats and interstitial telomeric sequences. Genes 10(2):118. https://doi.org/10.3390/genes10020118 - DOI - PubMed - PMC
    1. Alencar LR, Quental TB, Grazziotin FG, Alfaro ML, Martins M, Venzon M, Zaher H (2016) Diversification in vipers: phylogenetic relationships, time of divergence and shifts in speciation rates. Mol Phylogenet Evol 105:50–62. https://doi.org/10.1016/j.ympev.2016.07.029 - DOI - PubMed
    1. Altmanová M, Rovatsos M, Kratochvíl L, Johnson Pokorná M (2016) Minute y chromosomes and karyotype evolution in Madagascan iguanas (Squamata: Iguania: Opluridae). Biol J Linn Soc 118(3):618–633. https://doi.org/10.1111/bij.12751 - DOI
    1. Altmanová M, Doležálková-Kaštánková M, Jablonski D, Strachinis I, Vergilov V et al (2024) Karyotype stasis but species-specific repetitive DNA patterns in Anguis lizards (Squamata: Anguidae), in the evolutionary framework of Anguiformes. Zool J Linn Soc. https://doi.org/10.1093/zoolinnean/zlad153 - DOI

LinkOut - more resources