Biology subjects

Bengtsson, M.

Publications and source records attributed to Bengtsson, M..

4 recordsLinked to original sources

bioRxiv2018

Plant odour and sex pheromone are integral elements of specific mate recognition in an insect herbivore

Specific mate recognition strongly relies on the chemical senses in many animals, and especially in nocturnal insects. Two signal types lend to premating olfactory communication in terrestrial habitats: sex signals blend into an atmosphere of habitat odorants, where plant volatiles prevail. We show for the first time that males of the African cotton leafworm Spodoptera littoralis perceive female sex pheromone and volatiles of its plant host cotton as a unit, rather than as independent messages. In clean air, S. littoralis males are attracted to flawed pheromone signals, such as single synthetic pheromone components or even the pheromone of a sibling species, Oriental leafworm S. litura. Presence of host plant volatiles, however, strongly reduces the male response to deficient or heterospecific pheromone signals. That plant cues enhance discrimination of sex pheromone quality confirms the idea that specific mate recognition in noctuid moths has evolved in concert with host plant adaptation. A participation of host plant odour in sexual communication suggests that mate recognition is under natural and sexual selection. Moreover, shifts in either female host preference or sex pheromone biosynthesis give rise to new communication channels that have the potential to initiate or contribute to reproductive isolation.

evolutionary biology↗

bioRxiv2018

Inter- and intra-domain functional redundancy in the rumen microbiome during plant biomass degradation

BackgroundRuminant livestock is a major source of the potent greenhouse gas methane (CH4), produced by the complex rumen microbiome. Using an integrated approach, combining quantitative metatranscriptomics with gas- and volatile fatty acid (VFA) profiling, we gained fundamental insights into temporal dynamics of the cow rumen microbiome during feed degradation.\n\nResultsThe microbiome composition was highly individual and remarkably stable within each cow, despite similar gas emission and VFA profiles between cows. Gene expression profiles revealed a fast microbial growth response to feeding, reflected by drastic increases in microbial biomass, CH4 emissions and VFA concentrations. Microbiome individuality was accompanied by high inter- and intra-domain functional redundancy among pro- and eukaryotic microbiome members in the key steps of anaerobic feed degradation. Methyl-reducing but not CO2-reducing methanogens were correlated with increased CH4 emissions during plant biomass degradation.\n\nConclusionsThe major response of the rumen microbiome to feed intake was a general growth of the whole community. The high functional redundancy of the cow-individual microbiomes was possibly linked to the robust performance of the anaerobic degradation process. Furthermore, the strong response of methylotrophic methanogens is suggesting that they might play a more important role in ruminant CH4 emissions than previously assumed, making them potential targets for CH4 mitigation strategies.

microbiology↗

bioRxiv2017

The scent of the fly

(Z)-4-undecenal (Z4-11Al) is the volatile pheromone produced by females of the vinegar fly Drosophila melanogaster. Female flies emit Z4-11Al for species-specific communication and mate-finding. A sensory panel finds that synthetic Z4-11Al has a characteristic flavour, which we perceive even at the small amounts produced by one female fly. Since only females produce Z4-11Al, and not males, we can reliably distinguish between single D. melanogaster males and females, according to their scent. Females release Z4-11Al at 2.4 ng/h and we readily sense 1 ng synthetic Z4-11Al in a glass of wine (0.03 nmol/L), while a tenfold concentration is perceived as a loud off-flavour. This corroborates the observation that a glass of wine is spoilt by a single D. melanogaster fly falling into it, which we here show is caused by Z4-11Al. The biological role of Z4-11Al or structurally related aldehydes in humans and the basis for this semiochemical convergence remains yet unclear.

animal behavior and cognition↗

bioRxiv2016

The Drosophila pheromone Z4-11Al is encoded together with habitat olfactory cues and mediates species-specific communication

Mate recognition in animals evolves during niche adaptation and involves habitat and social olfactory signals. Drosophila melanogaster is attracted to fermenting fruit for feeding and egg-laying. We show that, in addition, female flies release a pheromone (Z)4-undecenal (Z4-11Al), that elicits flight attraction in both sexes. The biosynthetic precursor of Z4-11Al is the cuticular hydrocarbon (Z,Z)-7,11-heptacosadiene (7,11-HD), which is known to afford reproductive isolation between D. melanogaster and D. simulans. A pair of alternatively spliced receptors, Or69aB and Or69aA, is tuned to Z4-11Al and to food olfactory cues, respectively. These receptors are co-expressed in the same olfactory sensory neurons, and feed into a neural circuit mediating species-specific, long-range communication: the close relative D. simulans does not respond. That Or69aA and Or69aB have adopted dual olfactory traits highlights the interplay of habitat and social signals in mate finding. These olfactory receptor genes afford a collaboration between natural and sexual selection, which has the potential to drive phylogenetic divergence.

animal behavior and cognition↗