Biology subjects

Nikolouli, K.

Publications and source records attributed to Nikolouli, K..

3 recordsLinked to original sources

bioRxiv2025

Genome assembly of five Tephritid species for the enhancement of the Sterile Insect Technique

Tephritidae insect pests account for extensive crop damage and yield losses globally. Modern, sustainable pest management approaches are species-specific and, therefore, high-quality genome assemblies are required for their application. Here, we present chromosome-level assemblies for five members of the Tephritidae family: Anastrepha fraterculus, Anastrepha ludens, Bactrocera dorsalis, Bactrocera zonata and Zeugodacus cucurbitae. The assemblies used long read sequencing polished with short read sequencing and scaffolded using Hi-C (chromatin conformation capture) sequencing. Prior to scaffolding the assembly deduplication was performed to separate a primary assembly and an alternate assembly, and each was then scaffolded independently. The scaffolded assemblies reached N50 length in the range of 60Mb to 120Mb. The scaffolded assemblies were verified with BUSCO and completeness was in the range 97% to 98.5% and had very low duplicated, fragmented and missing orthologs.

ecology↗

bioRxiv2021

Marker-assisted mapping enables effective forward genetic analysis in the arboviral vector Aedes aegypti, a species with vast recombination deserts

Aedes aegypti is a major vector of arboviruses that cause dengue, chikungunya, yellow fever and Zika. Although recent success in reverse genetics has facilitated rapid progress in basic and applied research, integration of forward genetics with modern technologies remains challenging in this important species, as up-to-47% of its chromosome is refractory to genetic mapping due to extremely low rate of recombination. Here we report the development of a marker-assisted-mapping (MAM) strategy to readily screen for and genotype only the rare but informative recombinants, drastically increasing both the resolution and signal-to-noise ratio. Using MAM, we mapped a transgene that was inserted in a >100 Mb recombination desert and a sex-linked spontaneous red-eye (re) mutation just outside the region. We subsequently determined, by CRISPR/Cas9-mediated knockout, that cardinal is the causal gene of re, which is the first forward genetic identification of a causal gene in Ae. aegypti. This study provides the molecular foundation for using gene-editing to develop versatile and stable genetic sexing methods by improving upon the current re-based genetic sexing strains. MAM does not require densely populated markers and can be readily applied throughout the genome to facilitate the mapping of genes responsible for insecticide- and viral-resistance. By enabling effective forward genetic analysis, MAM bridges a significant gap in establishing Ae. aegypti as a model system for research in vector biology. As large regions of suppressed recombination are also common in other plant and animal species including those of economic significance, MAM will have broad applications beyond vector biology.

genetics↗

bioRxiv2020

White pupae genes in the Tephritids Ceratitis capitata, Bactrocera dorsalis and Zeugodacus cucurbitae: a story of parallel mutations

Mass releases of sterilized male insects, in the frame of sterile insect technique programs, have helped suppress insect pest populations since the 1950s. In the major horticultural pests Bactrocera dorsalis, Ceratitis capitata, and Zeugodacus cucurbitae, a key phenotype white pupae (wp) has been used for decades to selectively remove females before releases, yet the gene responsible remained unknown. Here we use classical and modern genetic approaches to identify and functionally characterize causal wp− mutations in these distantly related fruit fly species. We find that the wp phenotype is produced by parallel mutations in a single, conserved gene. CRISPR/Cas9-mediated knockout of the wp gene leads to the rapid generation of novel white pupae strains in C. capitata and B. tryoni. The conserved phenotype and independent nature of the wp− mutations suggest that this technique can provide a generic approach to produce sexing strains in other major medical and agricultural insect pests.Competing Interest StatementThe authors have declared no competing interest.View Full Text

genetics↗