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Biology subjects

Munro, M.

Publications and source records attributed to Munro, M..

3 recordsLinked to original sources

Hive position matters: spatial layout and hive colour impact forager traffic and drifting in Melipona quadrifasciata bees

Stingless bees are key pollinators of native and cultivated plants, and their management mostly for honey and hive commercialisation has become an increasingly popular practice in Brazil. Hives are commonly kept close together and visually similar in meliponaries, a practice that favours drifting, i.e., the return of foragers to a foreign nest. Distance between hives and layout have been identified as drivers of drifting in the Western honeybee, but evidence for stingless bees, the largest group of social bees, remains scarce. Additionally, stingless beekeepers frequently associate drifting with weakened colonies, uneven honey production, worker fighting, and colony population imbalances. We investigated the effects of hive layout on foraging traffic and drifting in the stingless bee Melipona quadrifasciata. We compared forager traffic across six layouts varying in distance, colour and entrance orientation. Then, using RFID tags, we tracked drifting across three layouts with the same inter-hive distance but different designs: visually similar hives, hives with opposite entrance orientation, and hives painted with distinct colours. Forager traffic was lowest in the visually similar layout during the first two weeks of monitoring, which is consistent with greater disorientation in the absence of clear visual cues. Hive position was a key driver of drifting behaviour across all layouts, with bees from edge hives drifting considerably less than those from inner hives. Drifting decreased considerably in hives with different colours (37.6%) and hives with entrances in opposite directions (48.1%), compared to similarly looking hives with entrances in the same direction (59.5%). Therefore, our findings highlight practical low-effort strategies for stingless beekeepers to reduce forager loss, pathogen spread, and productivity losses.

animal behavior and cognition↗

Temperature and turbidity interact synergistically to alter anti-predator behaviour in the Trinidadian guppy

Due to climate change, freshwater habitats are facing increasing temperatures and more extreme weather that disrupts water flow. Together with eutrophication and sedimentation from farming, quarrying and urbanisation, freshwaters are becoming more turbid as well as warmer. Predators and prey need to be able to respond to one another adaptively, yet how changes in temperature and turbidity interact to affect predator-prey behaviour remains unexplored. Using a fully factorial design, we tested the combined effects of increased temperature and turbidity on the behaviour of guppy shoals (Poecilia reticulata) in the presence of one of their natural cichlid predators, the blue acara (Andinoacara pulcher). Our results demonstrate that the prey and predator were in closest proximity in warmer, turbid water, with an interaction between these stressors showing a greater than additive effect. There was also an interaction between the stressors in the inter-individual distances between the prey, where shoal cohesion increased with temperature in clear water, but decreased when temperature increased in turbid water. The closer proximity to predators and reduction in shoaling in turbid, warmer water may increase the risk of predation for the guppy, suggesting that the combined effects of elevated temperature and turbidity may favour predators rather than prey.

animal behavior and cognition↗

CIP2A is a prime synthetic-lethal target for BRCA-mutated cancers

BRCA1/2-mutated cancer cells must adapt to the genome instability caused by their deficiency in homologous recombination. Identifying and targeting these adaptive mechanisms may provide new therapeutic strategies. Here we present the results of genome-scale CRISPR/Cas9-based synthetic lethality screens in isogenic pairs of BRCA1- and BRCA2-deficient cells that identified the gene encoding CIP2A as essential in a wide range of BRCA1- and BRCA2-mutated cells. Unlike PARP inhibition, CIP2A-deficiency does not cause accumulation of replication-associated DNA lesions that require homologous recombination for their repair. CIP2A is cytoplasmic in interphase but, in mitosis, accumulates at DNA lesions as part of a complex with TOPBP1, a multifunctional genome stability factor. In BRCA-deficient cells, the CIP2A-TOPBP1 complex prevents lethal mis-segregation of acentric chromosomes that arises from impaired DNA synthesis. Finally, physical disruption of the CIP2A-TOPBP1 complex is highly deleterious in BRCA-deficient cells and tumors, indicating that targeting this mitotic chromosome stability process represents an attractive synthetic-lethal therapeutic strategy for BRCA1- and BRCA2-mutated cancers.

cancer biology↗