Biodiversity of Drosophila species at a new university campus in Kunshan, China

Abstract

The project aimed to explore the biodiversity of Drosophila species in Kunshan using genomic approaches. DNA sequences, specifically the Cytochrome Oxidase I (COI) gene, were utilized as genetic "barcodes" to identify the organisms. Three wild-caught fruit flies and a D. melanogaster control were selected, and their DNA was isolated through PCR amplification of the COI gene. The PCR products were sequenced, and the results were used to create phylogenetic trees and uploaded to the Barcode of Life Database Student Data Portal (BOLD-SDP) alongside species photos. The results identified 10 Drosophila species, with 6 species remaining unchanged over two years and 3 new species discovered this year. One sample was identified as D. neohypocausta, a Chinese endemic species, which had appeared only in the last two years in Kunshan. However, its sample size was small, suggesting it may not be native to the area. Further research revealed significant genetic differentiation between different clades of D. immigrans, which likely explained the limited number of D. neohypocausta samples, as most D. immigrans species are confined to specific regions. To gain a comprehensive understanding of biogeographic, ecological, and evolutionary patterns across the Drosophila genus, expanded sampling and taxonomic revision are necessary, particularly for the large immigrans species groups that have been inferred as polyphyletic in some studies. This study underscores the importance of genomic approaches in taxon diagnosis and highlights the need for further exploration to uncover the intricate relationships within the Drosophila genus.