# The First Report of a Non-Canonical Telomeric Motif in Neuroptera: (TTGGG)n in Chromosomes of Nineta flava (Scopoli, 1763), Chrysopidae

## TL;DR

This study reports a new telomeric sequence (TTGGG)n in the Neuroptera insect Nineta flava, expanding our understanding of telomere diversity in this order.

## Contribution

The first report of the non-canonical (TTGGG)n telomeric motif in Neuroptera.

## Key findings

- (TTGGG)n was identified as the telomeric motif in Nineta flava with arrays ranging from 228 to 8005 bp.
- The canonical (TTAGG)n motif was found in Nothochrysa capitata but not in Chrysoperla carnea or Chrysopa pallens.
- No SART or TRAS retrotransposons were detected in any of the studied species.

## Abstract

Background: Telomeres are nucleoprotein complexes that maintain chromosome integrity in eukaryotes. In insects, the canonical telomeric repeat (TTAGG)n is considered ancestral, though alternative motifs exist across various orders. Neuroptera, comprising about 5800 species, remains understudied regarding telomeric sequences, with data available for only seven species across three families. Previous studies reported the absence of (TTAGG)n in Chrysopidae species, contrasting with its presence in other Neuroptera families. This study aimed to identify and characterize telomeric motifs in Chrysopidae using chromosome-level genome assemblies and search for retrotransposon insertions. Methods: We analyzed chromosome-level genome assemblies from four Chrysopidae species: three Chrysopinae—Chrysoperla carnea (Stephens, 1836), Chrysopa pallens (Rambur, 1838), and Nineta flava (Scopoli, 1763); and one Nothochrysinae—Nothochrysa capitata (Fabricius, 1793). Terminal sequences of chromosome pseudomolecules were examined using Geneious Prime®, applying five specific criteria for optimal telomeric sequence identification. We searched for SART and TRAS retrotransposons using the graphical sequence panel in GenBank. Results: We identified (TTGGG)n as the telomeric motif in N. flava, representing the first report of this pentanucleotide repeat in telomeres of Neuroptera. Arrays ranged from 228 to 8005 bp across seven terminal locations in five chromosome pseudomolecules. In N. capitata, we detected (TTAGG)n arrays (2316–3808 bp) at four terminal locations. No telomeric motifs meeting all criteria were found in C. carnea and C. pallens. No SART/TRAS retrotransposons were detected in any species. Conclusions: This study reveals previously unknown telomeric diversity within Chrysopidae, with both canonical (TTAGG)n and novel (TTGGG)n motifs present. The discovery of (TTGGG)n in Neuroptera expands known telomeric sequence diversity in this order.