Biology subjects

Otti, O.

Publications and source records attributed to Otti, O..

5 recordsLinked to original sources

bioRxiv2026

Evolution and adaptations of the seminal proteome in an insect with traumatic insemination

The protein composition of sperm and seminal fluid are key to male fitness. However, we currently lack an understanding of the factors that shape seminal proteome composition. The common bedbug (Cimex lectularius) mates by traumatic insemination, subjecting the ejaculate to a unique selective environment as sperm traverse the female genital and paragenital system. We provide the first high-throughput proteomic characterisation of the sperm and seminal fluid proteome in a hemimetabolous insect and the first in-depth proteomic characterisation of the male bedbug reproductive system. Our analysis revealed conserved and unique features of the sperm and seminal fluid proteome with possible links to features of sperm behaviour linked to traumatic insemination. The sperm proteome showed elevated rates of molecular evolution, unlike most other studied species. Conversely, the sperm proteome also contained many conserved proteins. Notably, we found an expansion of Sperm-leucylaminopeptidases (S-Laps) in bedbugs and other hemimetabolous insects, suggesting the origin of S-Laps is perhaps even more ancient than previously thought. Using in silico protein-ligand binding predictions, we show that S-Laps have likely retained catalytic activity. Our results provide a list of candidate proteins involved in reproduction and a foundation for future studies of this expanding global pest.

evolutionary biology↗

bioRxiv2022

Comparison of fitness effects in the earthworm Eisenia fetida after exposure to single or multiple anthropogenic pollutants

Terrestrial ecosystems are exposed to many anthropogenic pollutants. Non-target effects of pesticides and fertilizers have put agricultural intensification in the focus as a driver for biodiversity loss. However, other pollutants, such as heavy metals, particulate matter, or microplastic also enter the environment, e.g. via traffic and industrial activities in urban areas. As soil acts as a potential sink for such pollutants, soil invertebrates like earthworms may be particularly affected by them. Under natural conditions soil invertebrates will likely be confronted with combinations of pollutants simultaneously, which may result in stronger negative effects if pollutants act synergistically. Within this work we study how multiple pollutants affect the soil-dwelling, substrate feeding earthworm Eisenia fetida. We compared the effects of the single stressors, polystyrene microplastic fragments, polystyrene fibers, brake dust and soot, with the combined effect of these pollutants when applied as a mixture. Endpoints measured were survival, growth, reproductive fitness, and changes in three oxidative stress markers. We found that among single pollutant treatments, brake dust imposed the strongest negative effects on earthworms in all measured endpoints including increased mortality rates. Sub-lethal effects were found for all pollutants. Exposing earthworms to all four pollutants simultaneously led to effects on mortality and oxidative stress markers that were smaller than expected by the respective null models. These antagonistic effects are likely a result of the adsorption of toxic substances found in brake dust to the other pollutants. With this study we show that effects of combinations of pollutants cannot necessarily be predicted from their individual effects and that combined effects will likely depend on identity and concentration of the pollutants.

ecology↗

bioRxiv2021

The sperm-associated microbiota of crickets and their local variation and rapid turnover

While studying aspects of the sperm biology and immunity of two species of crickets, we encountered bacteria that were released from the male sperm container, the spermatophore, alongside sperm. We describe a presumably rich microbe flora in the sperm population ( sperm-associated microbiota). These sperm-associated microbiota differed between the two species of cricket and between different populations and showed functional diversity. Further, sperm-associated microbiota killed sperm, highlighting their potential role in fitness, especially since they are most likely transferred to females during mating.

evolutionary biology↗

bioRxiv2020

Transmission, tropism and biological impacts of torix Rickettsia in the common bed bug Cimex lectularius (Hemiptera: Cimicidae)

The torix group of Rickettsia have been recorded from a wide assemblage of invertebrates, but details of transmission and biological impacts on the host have rarely been established. The common bed bug (Cimex lectularius) is a hemipteran insect which lives as an obligatory hematophagous pest of humans and is host to a primary Wolbachia symbiont and two facultative symbionts, a BEV-like symbiont, and a torix group Rickettsia. In this study, we first note the presence of a single Rickettsia strain in multiple laboratory bed bug isolates derived from Europe and Africa. Importantly, we discovered that the Rickettsia has segregated in two laboratory strains, providing infected and uninfected isogenic lines for this study. Crosses with these lines established transmission was purely maternal, in contrast to previous studies of torix infections in planthoppers where paternal infection status was also important. Fluorescence in-situ hybridization analysis indicates Rickettsia infected in oocytes and bacteriomes, and other somatic tissues. There was no evidence that Rickettsia infection was associated with sex ratio distortion activity, but Rickettsia infected individuals developed from first instar to adult more slowly. The impact of Rickettsia on fecundity and fertility were investigated. Rickettsia infected females produced fewer fertile eggs, but there was no evidence for cytoplasmic incompatibility. These data imply the existence of an unknown benefit to C. lectularius carrying Rickettsia that awaits further research.

zoology↗

bioRxiv2019

Mating changes the genital microbiome in both sexes of the common bedbug Cimex lectularius across populations

Many bacteria live on host surfaces, in cells, and specific organ systems. Although gut microbiomes of many organisms are well-documented, the bacterial communities of reproductive organs, i.e. genital microbiomes, have received little attention. During mating, male and female genitalia interact and copulatory wounds can occur, providing an entrance for sexually transmitted microbes. Besides being potentially harmful to the host, invading microbes might interact with resident genital microbes and affect immunity. While sexual transmission of individual symbiont species is relatively well-understood, few studies have addressed how mating changes genital microbiomes. Here, we characterize male and female genital microbiomes in four different populations of the common bedbug Cimex lectularius and investigate mating-induced changes. We dissected reproductive organs from virgin and mated individuals to sequence their genital microbiomes. We show that mating changes genital microbiomes, suggesting bacteria are sexually transmitted. This raises the question how the hosts physiological and immunological mechanisms control mating-induced changes in their genital microbiomes. Also, genital microbiomes varied between populations and the sexes. This provides evidence for local and sex-specific adaptation of bacteria and hosts, again suggesting that bacteria might play an important role in shaping the evolution of reproductive traits. Coadaptation of genital microbiomes and reproductive traits might further lead to reproductive isolation between populations, giving reproductive ecology an important role in speciation. Future studies should investigate the transmission dynamics between the sexes and populations to uncover potential reproductive barriers.

evolutionary biology↗