Biology subjects

Oldroyd, B. P.

Publications and source records attributed to Oldroyd, B. P..

4 recordsLinked to original sources

bioRxiv2022

A long non-coding RNA is a key factor in the evolution of insect eusociality

Insect sociality is a major evolutionary transition based on the suppression of worker reproduction in favor of the reproductive monopoly of the queen. In the honey bee (Apis mellifera) model organism, the development of the two female caste phenotypes, queen and worker, is triggered by differences in their larval diets. However, the mechanistic details underlying their respective developmental trajectories, as well as the maintenance of sterility in the adult workers, are still not fully understood. Here we show that the long non-coding RNA lncov1 interacts with the Tudor staphylococcus nuclease (Tudor-SN) protein to form a regulatory module that promotes apoptosis in the ovaries of worker larvae. In adult workers, the lncov1/Tudor-SN module responds positively to environmental cues that suppress reproductive capacity. As lncov1 is considerably conserved in the Apidae, we propose that, by promoting worker sterility, the lncov1/Tudor-SN module has likely played critical roles in the social evolution of bees.

evolutionary biology↗

bioRxiv2021

Abundant small RNAs in the reproductive tissues of the honey bee, Apis mellifera, are a plausible mechanism for epigenetic inheritance and parental manipulation of gene expression

Polyandrous social insects such as the honey bee are prime candidates for parental manipulation of gene expression in offspring. Although there is good evidence for parent-of-origin effects in honey bees the epigenetic mechanisms that underlie these effects remain a mystery. Small RNA molecules such as miRNAs, piRNAs and siRNAs play important roles in transgenerational epigenetic inheritance and in the regulation of gene expression during development. Here we present the first characterisation of small RNAs present in honey bee reproductive tissues: ovaries, spermatheca, semen, fertilised and unfertilised eggs, and testes. We show that semen contains fewer piRNAs relative to eggs and ovaries, and that piRNAs and miRNAs which map antisense to genes involved in DNA regulation and developmental processes are differentially expressed between tissues. tRNA fragments are highly abundant in semen and have a similar profile to those seen in semen in other animals. Intriguingly we find abundant piRNAs that target the sex determination locus, suggesting that piRNAs may play a role in honey bee sex determination. We conclude that small RNAs play a fundamental role in honey bee gametogenesis and reproduction and provide a plausible mechanism for parent-of origin-effects on gene expression and reproductive physiology.

genomics↗

bioRxiv2021

Regulation of oogenesis in the queen honey bee (Apis mellifera)

In the honey bee (Apis mellifera), queen and worker castes originate from identical genetic templates but develop into different phenotypes. Queens lay up to 2,000 eggs daily whereas workers are sterile in the queens presence. Periodically queens stop laying; during swarming, when resources are scarce in winter and when they are confined to a cage by beekeepers. We used confocal microscopy and gene expression assays to investigate the control of oogenesis in honey bee queen ovaries. We show that queens use different combination of checkpoints to regulate oogenesis compared to honey bee workers and other insect species. However, both queen and worker castes use the same programmed cell death pathways to terminate oocyte development at their caste-specific checkpoints. Our results also suggest that the termination of oogenesis in queens is driven by nutritional stress. Thus, queens may regulate oogenesis via the same regulatory pathways that were utilised by ancestral solitary species but have adjusted physiological checkpoints to suit their highly-derived life history. Summary statementHoney bee queens regulate oogenesis using a different combination of checkpoints to workers, but both castes use the same molecular pathways.

developmental biology↗

bioRxiv2020

Queen pheromone modulates the expression of epigenetic modifier genes in the brain of honey bee workers

Pheromones are used by many insects to mediate social interactions. In the highly eusocial honeybee (Apis mellifera) queen mandibular pheromone (QMP) is involved in the regulation of reproduction and behaviour of workers. The molecular mechanisms by which QMP acts are largely unknown. Here we investigate how genes responsible for epigenetic modifications to DNA, RNA and histones respond to the presence of QMP. We show that several of these genes are upregulated in the honeybee brain when workers are exposed to QMP. This provides a plausible mechanism by which pheromone signalling may influence gene expression in the brain of honeybee workers. We propose that pheromonal communication systems, such as those used by social insects, evolved to respond to environmental signals by making use of existing epigenomic machineries.

ecology↗