Biology subjects

Dominguez, J. A.

Publications and source records attributed to Dominguez, J. A..

3 recordsLinked to original sources

bioRxiv2024

Resource competition affects the developmental outcome of the acoustic parasitoid fly Ormia ochracea

Ormia ochracea is an acoustic parasitoid fly where the adults are free-living, but their larval young depend on nutritional resources within host crickets for growth and development. In nature, gravid female flies rely on their ability to recognize and localize cricket calling songs to find suitable host species to parasitize. In depth investigations of fly behavior and the mechanistic bases of auditory perception require a reliable approach to propagate stable fly colonies in the laboratory. Previous work has demonstrated that flies can be propagated using a number of natural host cricket species, as well as cricket species that flies do not parasitize in nature. However, we lack a complete understanding of fly developmental outcomes when non-host cricket species are utilized to propagate fly colonies. In this study, we document the feasibility of using commercially supplied Acheta domesticus as a host species. We specifically test the hypothesis that host size and resource competition can affect developmental outcomes of O. ochracea. We performed manual parasitizations on crickets that varied in size, and resource competition was varied by manipulating the number of larvae used to parasitize a host cricket. A series of morphometric analyses were conducted on host crickets, and developmental outcomes were measured in terms of pupation success and eclosion success, pupal width, and eclosed adult fly size. In the absence of resource competition, we found that host cricket size did not affect pupation or eclosion success. In the presence of resource competition between two developing larvae within a host cricket, pupation and eclosion successes were impacted negatively, and the developing pupae were more likely to be smaller. These results confirm that resource competition among developing parasitoids can negatively affect developmental outcomes, and Acheta domesticus can be used effectively to propagate colonies of O. ochracea in the laboratory. HighlightsO_LIThe acoustic parasitoid fly Ormia ochracea can successfully develop within the house cricket Acheta domesticus. C_LIO_LIPupal size and eclosed adult fly size varies positively with the size of host cricket. C_LIO_LIResource competition negatively affects pupation and eclosion success. C_LIO_LIResource competition resulted in smaller fly pupae that were less likely to eclose. C_LI Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=192 HEIGHT=200 SRC="FIGDIR/small/590943v1_ufig1.gif" ALT="Figure 1"> View larger version (40K): org.highwire.dtl.DTLVardef@b86e19org.highwire.dtl.DTLVardef@44444corg.highwire.dtl.DTLVardef@1dfe813org.highwire.dtl.DTLVardef@fd5b3b_HPS_FORMAT_FIGEXP M_FIG C_FIG

physiology↗

bioRxiv2023

Effects of Ambient Temperature on the Recognition and Preferences for Host Song Pulse-rate by the Acoustic Parasitoid Fly Ormia ochracea

Receivers of acoustic communication signals evaluate signal features to correctly identify conspecifics. Environmental variation such as changes in the ambient temperature can alter signal features that may render species recognition a challenge. In field crickets, song temporal features evaluated for species recognition vary with temperature, and the intended receivers of these signals exhibit signal preferences that are temperature-coupled to maintain effective communication. Whether eavesdroppers of communication signals exhibit similar temperature-coupled preferences is unknown. Here, we investigate whether the parasitoid fly Ormia ochracea, an eavesdropper of cricket calling songs, exhibit song pulse rate preferences that are temperature-coupled. We use a high-speed treadmill system to record walking phonotaxis at three ambient temperatures (21, 25, and 30 {degrees}C) in response to songs that varied in pulse rates (20 to 90 pulses per second). Total walking distance, peak steering velocity, angular heading, and the phonotaxis performance index varied with song pulse rates and were affected by ambient temperature. The peak of phonotaxis performance index preference functions became broader and exhibited a "high-pass" shape, shifting to higher pulse rate values at higher temperatures. Temperature related changes in cricket songs between 21-30 {degrees}C will not drastically affect the ability of flies to recognize cricket calling songs.

animal behavior and cognition↗

bioRxiv2022

An updated evolutionary history and taxonomy of Mycobacterium tuberculosis lineage 5, also called M. africanum

Contrarily to other lineages such as L2 and L4, there are still scarce whole-genome-sequence data on L5-L6 MTBC clinical isolates in public genomes repositories. Recent results suggest a high complexity of L5 history in Africa. It is of importance for an adequate assessment of TB infection in Africa, that is still related to the presence of L5-L6 MTBC strains. This study reports a significant improvement of our knowledge of L5 diversity, phylogeographical history, and global population structure of Mycobacterium africanum L5. To achieve this aim, we sequenced new clinical isolates from Northern Nigeria and from proprietary collections, and used a new powerful bioinformatical pipeline, TB-Annotator that explores not only the shared SNPs but also shared missing genes, identical IS6110 insertion sites and shared regions of deletion. This study using both newly sequenced genomes and available public genomes allows to describe new L5 sublineages. We report that the MTBC L5 tree is made-up of at least 12 sublineages from which 6 are new descriptions. We confront our new classification to the most recent published one and suggest new naming for the discovered sublineages. Finally, we discuss the phylogeographical specificity of sublineages 5.1 and sublineage 5.2 and suggest a new hypothesis of L5-L6 emergence in Africa. Impact statementRecent studies on Mycobacterium africanum (L5-L6-L9 of MTBC) genomic diversity and its evolution in Africa discovered three new lineages of the Mycobacterium tuberculosis complex (MTBC) in the last ten years (L7, L8, L9). These discoveries are symptomatic of the delay in characterizing the diversity of the MTBC on the African continent. Another understudied part of MTBC diversity is the intra-lineage diversity of L5 and L6. This study unravels an hidden diversity of L5 in Africa and provides a more exhaustive description of specific genetic features of each sublineage by using a proprietary "TB-Annotator" pipeline. Furthermore, we identify different phylogeographical localization trends between L5.1 and L5.2, suggesting different histories. Our results suggest that a better understanding of the spatiotemporal dynamics of MTBC in Africa absolutely requires a large sampling effort and powerful tools to dig into the retrieved diversity. Data summary[A section describing all supporting external data, software or code, including the DOI(s) and/or accession numbers(s), and the associated URL. If no data was generated or reused in the research, please state this.] The search was done in the TB-Annotator 15901 genomes version which is available at: http://(to be added). The new sequenced genomes are available via NCBI Bioproject accession number: (to be added). The authors confirm all supporting data, code and protocols have been provided within the article or through supplementary data files.

genomics↗