Project description:Deep whole genome sequencing of Drosophila melanogaster inbred lines: DGRP-28, DGRP-307, DGRP-399, DGRP-57, DGRP-639, DGRP-712, DGRP-714, DGRP-852 and Virginizer (VGN). The lines were sequenced deeply giving between 54M and 92M reads to achieve a whole genome coverage that ranged between 74X and 125X. The sequencing was used for de novo genotyping.
Project description:The binding patterns of some transcription factors have been shown to diverge substantially between closely related species. Here, we show that the binding pattern of the developmental transcription factor Twist is highly conserved across six Drosophila species, revealing strong functional constraints at developmental enhancers. Conserved binding correlates with sequence motifs for Twist and its partners, permitting the de novo discovery of their cooperative binding. It also includes over 10,000 low-occupancy sites near the detection limit, which tend to mark enhancers of later developmental stages. We predict that conservation, dynamic occupancy, and combinatorial regulation will be generally true for developmental enhancers.
Project description:Flow cytometry estimates of genome sizes among species of Drosophila show a 3-fold variation, ranging from ∼127 Mb in Drosophila mercatorum to ∼400 Mb in Drosophila cyrtoloma. However, the assembled portion of the Muller F element (orthologous to the fourth chromosome in Drosophila melanogaster) shows a nearly 14-fold variation in size, ranging from ∼1.3 Mb to >18 Mb. Here, we present chromosome-level long-read genome assemblies for 4 Drosophila species with expanded F elements ranging in size from 2.3 to 20.5 Mb. Each Muller element is present as a single scaffold in each assembly. These assemblies will enable new insights into the evolutionary causes and consequences of chromosome size expansion.
Project description:Traumatic insemination (TI) is a rare reproductive behaviour characterized by the transfer of sperm to the female via puncture wounds inflicted across her body wall. Here, we challenge the claim made by Kamimura (Kamimura 2007 Biol. Lett. 3, 401-404. (doi:10.1098/rsbl.2007.0192)) that males of species of the Drosophila bipectinata complex use a pair of claw-like processes (claws) to traumatically inseminate females: the claws are purported to puncture the female body wall and genital tract, and to inject sperm through the wounds into the lumen of her genital tract, bypassing the vaginal opening. This supposed case of TI is widely cited and featured in prominent subject reviews. We examined high-resolution scanning electron micrographs of the claws and failed to discover any obvious 'groove' for sperm transport. We demonstrated that sperm occurred in the female reproductive tract as a single-integrated unit, inconsistent with the claim that sperm are injected via paired processes. Laser ablation of the sharp terminal ends of the claws failed to inhibit insemination. We showed that the aedeagus in the complex delivers sperm through the vaginal opening, as in other Drosophila. The results refute the claim of TI in the Drosophila bipectinata species complex.