Biology subjects

Maeda, R. K.

Publications and source records attributed to Maeda, R. K..

4 recordsLinked to original sources

bioRxiv2025

Characterization of the Post-Mating Responses of Drosophila hydei, a species that lacks Sex-Peptide.

Female post-mating responses (PMRs) in Drosophila melanogaster rely on proteins made by the male that are transferred to the female upon mating to modify her behavior and physiology. Many of the most characterized responses are initiated by a single protein produced by the male accessory gland called the Sex Peptide (SP). Yet many Drosophila species, even those living in similar environments, do not have SP. As PMRs are thought to be mechanisms used to maximize reproductive success, we wondered if PMRs are similar in species living in the same environment and how PMRs might be achieved in species that lack SP. Here, we investigate the post-mating responses of D. hydei. D. hydei is a Drosophilid that lacks SP, but is often found cohabitating with D. melanogaster. We show that the PMR in D. hydei is markedly different from that found in D. melanogaster; D. hydei do not increase egg production, nor do they limit remating to additional males or change their diet after mating. Instead, hydei seem to display only subtle PMRs related to activity patterns, in a way distinct from those characterized in D. melanogaster. These changes seem to have impacted things like lifespan and sperm selection, and demonstrate the wide variety of choices that species can make and be successful in a given environment.

evolutionary biology↗

bioRxiv2025

Drosophila Video-assisted Activity Monitor (DrosoVAM): a versatile method for behavior monitoring

Drosophila melanogaster has been a pioneering model system for investigations into the genetic bases of behavior. Studies of circadian activity were some of the first behaviors investigated in flies. The DAM system by TriKinetics played a key role in establishing the fundamental feedback loop of the circadian clock. Although this method has many time proven to be extremely useful, it suffers from its simplification of activity to the interruption of an infrared beam. It is blind to fly movements not disrupting the beam and any modifications to this assay to achieve better resolution often requires the purchase of new and expensive modules. We required a relatively high-throughput system to explore the potential post-mating activity changes of larger Drosophila species. Rather than investing in a larger and more-complex DAM system, we designed a new monitoring system that is more versatile, economic and sensitive than DAM. This new system, called DrosoVAM (Drosophila Video-assisted Activity Monitoring), is simple to implement and cost efficient, using a Raspberry Pi-controlled infrared, digital video system to record multiple chambers and Python scripts that drives the deep learning software DeepLabCut, to track fly activity over multiple days.

animal behavior and cognition↗

bioRxiv2021

Repression of the Hox gene abd-A by ELAV-mediated Transcriptional Interference

Intergenic transcription is a common feature of eukaryotic genomes and performs important and diverse cellular functions. Here, we investigate the iab-8 ncRNA from the Drosophila Bithorax Complex and show that this RNA is able to repress the transcription of genes located at its 3 end by a sequence-independent, transcriptional interference mechanism. Although this RNA is expressed in the early epidermis and CNS, we find that its repressive activity is limited to the CNS, where in wild-type embryos, it acts on the Hox gene, abd-A located immediately downstream of it. The CNS specificity is achieved through a 3 extension of the transcript, mediated by the neuronal-specific, RNA-binding protein, ELAV. Loss of ELAV activity eliminates the 3 extension and results in the ectopic activation of abd-A. Thus, a tissue-specific change in the length of a ncRNA is used to generate a precise pattern of gene expression in a higher eukaryote.

genetics↗

bioRxiv2018

Rab-mediated trafficking in the secondary cells of Drosophila male accessory glands and its role in fecundity

It is known that the male seminal fluid contains factors that affect female post-mating behavior and physiology. In Drosophila, most of these factors are secreted by the two epithelial cell types that make up the male accessory gland: the main and secondary cells. Although secondary cells represent only 4% of the cells of the accessory gland, their contribution to the male seminal fluid is essential for sustaining the female post-mating response. To better understand the function of the secondary cells, here we investigate their molecular organization, particularly with respect to the intracellular membrane transport machinery. We determined that large vacuole-like structures found in the secondary cells are trafficking hubs labeled by Rab6, 7, 11 and 19. Furthermore, these cell-specific organelles are essential for the long-term post-mating behavior of females and that their formation is directly dependent upon Rab6. Our discovery adds to our understanding of Rab proteins function in secretory cells. We have created an online, open-access imaging resource as a valuable tool for the intracellular membrane and protein traffic community.

cell biology↗