Papers by María del Mar Labrador
Microbial Ecology, Feb 16, 2021
of a potential problem with the word stylosphere. Indeed, our proposal to use stylosphere to name... more of a potential problem with the word stylosphere. Indeed, our proposal to use stylosphere to name feathers as the habitat where different organisms live and interact was based on the wrong interpretation that stylo means "feather" in Greek. Thus, we rather propose the use of pterosphere from Greek pteron ("feather" or "wing", here used as "feather") + sphaira ("ball" or "globe"), and ask colleagues to use pterosphere instead of stylosphere.
Comprehending symbiont abundance among host species is a major ecological endeavour, and the meta... more Comprehending symbiont abundance among host species is a major ecological endeavour, and the metabolic theory of ecology has been proposed to understand what constraints symbiont populations. We parameterized metabolic theory equations to predict how bird species' body size and the body size of their feather mites relate to mite abundance according to four potential energy (microbial abundance, uropygial gland size) and space constraints (wing area, number of feather barbs). Predictions were compared with the empirical scaling of feather mite abundance from 26,604 birds of 106 passerine species, using phylogenetic modelling and quantile regression. Feather mite populations were strongly constrained by host space (number of feather barbs) and not energy. Moreover, feather mite species' body size was unrelated to their abundance or to the body size of their host species. We discuss the implications of our results for our understanding of the bird-feather mite system and for sy...
Microbial Ecology, 2021
of a potential problem with the word stylosphere. Indeed, our proposal to use stylosphere to name... more of a potential problem with the word stylosphere. Indeed, our proposal to use stylosphere to name feathers as the habitat where different organisms live and interact was based on the wrong interpretation that stylo means "feather" in Greek. Thus, we rather propose the use of pterosphere from Greek pteron ("feather" or "wing", here used as "feather") + sphaira ("ball" or "globe"), and ask colleagues to use pterosphere instead of stylosphere.
Microbial Ecology, 2020
Feathers are the habitat of a myriad of organisms, from fungi and bacteria to lice and mites. Alt... more Feathers are the habitat of a myriad of organisms, from fungi and bacteria to lice and mites. Although most studies focus on specific taxa and their interaction with the bird host, anecdotal data glimpse feathers as holders of a system with its own ecology, what we call here the stylosphere. A major gap in our knowledge of the stylosphere is the ecology of the total abundance of microorganisms, being also rare to find studies that analyze abundance of more than one group of microorganisms at the bird interspecific level. Here, we quantified bacterial and fungi abundances through qPCR on the wing feathers of 144 birds from 24 passerine and one non-passerine bird species from three localities in Southern Spain. Bacteria and fungi abundances spanned three orders of magnitude among individual birds, but were consistent when comparing the right and the left wing feathers of individuals. Sampling locality explained ca. 14% of the variation in both bacteria and fungi abundances. Even when statistically controlling for sampling locality, microbial abundances consistently differed between birds from different species, but these differences were not explained by bird phylogeny. Finally, bird individuals and species having more bacteria also tended to held larger abundances of fungi. Our results suggest a quite complex explanation for stylosphere microorganisms' abundance, being shaped by bird individual and species traits, as well as environmental factors, and likely bacteria-fungi interactions.
Trends in parasitology, Aug 1, 2017
Intimate symbiotic [ 3 2 _ T D $ D I F F ] relationships between species (e.g., between a larger ... more Intimate symbiotic [ 3 2 _ T D $ D I F F ] relationships between species (e.g., between a larger 'host' and a smaller 'symbiont') span the range from mutualism to parasitism. The nature of a symbiotic relationship is not an intrinsic trait of the species involved, but rather the outcome of their interaction. Many symbiont species move along the mutualism-parasitism continuum depending on the environmental conditions [1]. For instance, defensive symbionts act as mutualists when they clean hosts of parasites, but they may harm their hosts when there are no parasites to clean [2]. Similarly, parasites can become mutualists under some conditions, as exemplified by the Drosophila symbiont, Wolbachia [3]. Also, lineages often move along this continuum in evolutionary time [4]. However, boundaries between scientific disciplines are not so permeable.
Limnology and Oceanography, 2014
The patchy distribution of oligopeptide production abilities in cyanobacterial populations enable... more The patchy distribution of oligopeptide production abilities in cyanobacterial populations enables the classification of strains into different oligopeptide-based chemotypes. In order to evaluate the ecological significance of chemotypes in natural systems, we tracked the seasonal dynamics and sedimentation losses of Microcystis chemotypes in the eutrophic Valmayor reservoir (Spain). Fifty-three distinct chemotypes were identified throughout the season, six of them only present as benthic colonies. There was no correlation between chemotype affiliation and taxonomic morphospecies or colony size. The succession of chemotypes in the water column occurred synchronically in pelagic and littoral habitats and at different depths. Shifts in chemotype assemblages successfully explained temporal fluctuations in biomass-standardized microcystin contents of the bloom. The dynamics of chemotypes were driven both by asynchronous proliferation in the water column and significantly different sedimentation rates among chemotypes. While differential settling was the most important loss process shaping chemotype succession, the existence of alternative processes selectively inflicting massive losses to individual chemotypes was observed. Together, the significant differences in sedimentation and pelagic net growth rates among chemotypes, their segregation among pelagic and benthic habitats, as well as the existence of chemotype-selective loss processes, show that Microcystis oligopeptide chemotypes interact differently with their environment and represent commonly overlooked ecologically functional intraspecific linages.
Microbial Ecology, 2021
Feathers are the habitat of a myriad of organisms, from fungi and bacteria to lice and mites. Alt... more Feathers are the habitat of a myriad of organisms, from fungi and bacteria to lice and mites. Although most studies focus on specific taxa and their interaction with the bird host, anecdotal data glimpse feathers as holders of a system with its own ecology, what we call here the stylosphere. A major gap in our knowledge of the stylosphere is the ecology of the total abundance of microorganisms, being also rare to find studies that analyze abundance of more than one group of microorganisms at the bird interspecific level. Here, we quantified bacterial and fungi abundances through qPCR on the wing feathers of 144 birds from 24 passerine and one non-passerine bird species from three localities in Southern Spain. Bacteria and fungi abundances spanned three orders of magnitude among individual birds, but were consistent when comparing the right and the left wing feathers of individuals. Sampling locality explained ca. 14% of the variation in both bacteria and fungi abundances. Even when statistically controlling for sampling locality, microbial abundances consistently differed between birds from different species, but these differences were not explained by bird phylogeny. Finally, bird individuals and species having more bacteria also tended to held larger abundances of fungi. Our results suggest a quite complex explanation for stylosphere microorganisms' abundance, being shaped by bird individual and species traits, as well as environmental factors, and likely bacteria-fungi interactions.
The patchy distribution of oligopeptide production abilities in cyanobacterial populations enable... more The patchy distribution of oligopeptide production abilities in cyanobacterial populations enables the classification of strains into different oligopeptide-based chemotypes. In order to evaluate the ecological significance of chemotypes in natural systems, we tracked the seasonal dynamics and sedimentation losses of Microcystis chemotypes in the eutrophic Valmayor reservoir (Spain). Fifty-three distinct chemotypes were identified throughout the season, six of them only present as benthic colonies. There was no correlation between chemotype affiliation and taxonomic morphospecies or colony size. The succession of chemotypes in the water column occurred synchronically in pelagic and littoral habitats and at different depths. Shifts in chemotype assemblages successfully explained temporal fluctuations in biomass-standardized microcystin contents of the bloom. The dynamics of chemotypes were driven both by asynchronous proliferation in the water column and significantly different sedimentation rates among chemotypes. While differential settling was the most important loss process shaping chemotype succession, the existence of alternative processes selectively inflicting massive losses to individual chemotypes was observed. Together, the significant differences in sedimentation and pelagic net growth rates among chemotypes, their segregation among pelagic and benthic habitats, as well as the existence of chemotype-selective loss processes, show that Microcystis oligopeptide chemotypes interact differently with their environment and represent commonly overlooked ecologically functional intraspecific linages.
The cyanobacterium Microcystis aggregates into colonies with a mucilaginous sheath that constitut... more The cyanobacterium Microcystis aggregates into colonies with a mucilaginous sheath that constitutes a special microhabitat for many microorganisms that associate to it. Here, we examine the notorious, yet scarcely studied case of epiphytic association by the cyanobacterium Pseudanabaena sp. to colonial Microcystis. Co-cultivation of Pseudanabaena with different Microcystis strains evidenced strong specificity in the interaction, with dramatically different outcomes in each case, including (1) inability of Pseudanabaena to access the slime of Microcystis, (2) neutral coexistence of epiphytic Pseudanabaena and Microcystis, and (3) rapid epiphytic proliferation of Pseudanabaena, followed by lysis and rapid decay of Microcystis cells. Whereas strain-specific oligopeptide production could not explain the observed specificity, differences in slime microstructures among Microcystis strains revealed by low-temperature scanning electron microscopy suggest that slime structural features might initially determine the ability of Pseudanabaena to colonize Microcystis, subsequently driving the outcome of the interaction. Furthermore, even under ''neutral'' coexistence , Pseudanabaena proliferation results in an increase in density that leads to colony settling, implying potential selective losses under natural conditions. Both the selective and antagonistic characters of the interaction indicate that epiphytic Pseudanabaena have the potential to contribute to the dynamics of strains in natural Microcystis communities.
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Papers by María del Mar Labrador