| 1. |
- Boquete, María Teresa, et al.
(författare)
-
Current and historical factors drive variation of reproductive traits in unisexual mosses in Europe : A case study
- 2023
-
Ingår i: Journal of Systematics and Evolution. - : Wiley. - 1674-4918 .- 1759-6831. ; 61:1, s. 213-226
-
Tidskriftsartikel (refereegranskat)abstract
- Unisexual bryophytes provide excellent models to study the mechanisms that regulate the frequency of sexual versus asexual reproduction in plants, and their ecological and evolutionary implications. Here, we determined sex expression, phenotypic sex ratio, and individual shoot traits in 242 populations of the cosmopolitan moss Pseudoscleropodium purum spanning its whole distributional range. We tested whether niche differentiation, sex-specific differences in shoot size, and biogeographical history explained the spatial variation of reproductive traits. We observed high levels of sex expression and predominantly female-biased populations, although both traits showed high intraspecific variation among populations. Sex expression and sex ratio were partly explained by current macroscale environmental variation, with male shoots being less frequent at the higher end of the environmental gradients defined by the current distribution of the species. Female bias in population sex ratio was significantly lower in areas recolonized after the last glacial maximum (recent populations) than in glacial refugia (long-term persistent populations). We demonstrated that reproductive trait variation in perennial unisexual mosses is partially driven by macroscale and historical environmental variation. Based on our results, we hypothesize that sexual dimorphism in environmental tolerance and vegetative growth contribute to sex ratio bias over time, constraining the chances of sexual reproduction, especially in long-term persistent populations. Further studies combining genetic analyses and population monitoring should improve our understanding of the implications of the intraspecific variation in the frequency of sexual versus asexual reproduction in bryophyte population fitness and eco-evolutionary dynamics.
|
|
| 2. |
- Ortigoza-Escobar, Juan Darío, et al.
(författare)
-
Free-thiamine is a potential biomarker of thiamine transporter-2 deficiency: a treatable cause of Leigh syndrome.
- 2016
-
Ingår i: Brain : a journal of neurology. - : Oxford University Press (OUP). - 1460-2156. ; 139:Pt 1, s. 31-8
-
Tidskriftsartikel (refereegranskat)abstract
- Thiamine transporter-2 deficiency is caused by mutations in the SLC19A3 gene. As opposed to other causes of Leigh syndrome, early administration of thiamine and biotin has a dramatic and immediate clinical effect. New biochemical markers are needed to aid in early diagnosis and timely therapeutic intervention. Thiamine derivatives were analysed by high performance liquid chromatography in 106 whole blood and 38 cerebrospinal fluid samples from paediatric controls, 16 cerebrospinal fluid samples from patients with Leigh syndrome, six of whom harboured mutations in the SLC19A3 gene, and 49 patients with other neurological disorders. Free-thiamine was remarkably reduced in the cerebrospinal fluid of five SLC19A3 patients before treatment. In contrast, free-thiamine was slightly decreased in 15.2% of patients with other neurological conditions, and above the reference range in one SLC19A3 patient on thiamine supplementation. We also observed a severe deficiency of free-thiamine and low levels of thiamine diphosphate in fibroblasts from SLC19A3 patients. Surprisingly, pyruvate dehydrogenase activity and mitochondrial substrate oxidation rates were within the control range. Thiamine derivatives normalized after the addition of thiamine to the culture medium. In conclusion, we found a profound deficiency of free-thiamine in the CSF and fibroblasts of patients with thiamine transporter-2 deficiency. Thiamine supplementation led to clinical improvement in patients early treated and restored thiamine values in fibroblasts and cerebrospinal fluid.
|
|
| 3. |
- Taboada, Sergi, et al.
(författare)
-
Genetic diversity, gene flow and hybridization in fan-shaped sponges (Phakellia spp.) in the North-East Atlantic deep sea
- 2022
-
Ingår i: Deep Sea Research Part I. - : Elsevier. - 0967-0637 .- 1879-0119. ; 181
-
Tidskriftsartikel (refereegranskat)abstract
- Deep-sea North Atlantic sponge grounds are crucial components of the marine fauna providing a key role in ecosystem functioning. To properly develop effective conservation and management plans, it is crucial to understand the genetic diversity, molecular connectivity patterns and turnover at the population level of the species involved. Here we present the study of two congeneric sponges, Phakellia robusta and Phakellia hirondellei, using multiple sources of evidence. Our phylogenetic study using a fragment of COI placed these two species as sister. Haplotype network analysis using COI revealed no genetic structure for P. hirondellei in samples from the Cantabrian Sea (<100 km). Contrastingly, P. robusta showed a clear genetic structure separating deep-water samples from the Cantabrian Sea and the Hatton-Rockall Basin, from samples from shallower waters from Kerry Head Reefs, NW of Orkney, and Norway. ddRADseq-derived SNPs for P. robusta also segregated samples by bathymetry rather than by geographical distances, and detected a predominant northwards migration for shallow-water specimens connecting sites separated ca. 2,000 km, probably thanks to prevalent oceanographic currents. Importantly, our analysis using SNPs combining the datasets of the two species revealed the presence of potential hybrids, which was corroborated by morphological (spicule) and microbial (16S amplicon sequencing) analyses. Our data suggest that hybridization between these two species occurred at least two times in the past. We discuss the importance of using next-generation techniques to unveil hybridization and the implications of our results for conservation.
|
|
| 4. |
- Taboada, Sergi, et al.
(författare)
-
Long distance dispersal and oceanographic fronts shape the connectivity of the keystone sponge Phakellia ventilabrum in the deep northeast Atlantic
- 2023
-
Ingår i: Frontiers in Marine Science. - : Frontiers Media S.A.. - 2296-7745. ; 10
-
Tidskriftsartikel (refereegranskat)abstract
- Little is known about dispersal in deep-sea ecosystems, especially for sponges, which are abundant ecosystem engineers. Understanding patterns of gene flow in deep-sea sponges is essential, especially in areas where rising pressure from anthropogenic activities makes difficult to combine management and conservation. Here, we combined population genomics and oceanographic modelling to understand how Northeast Atlantic populations (Cantabrian Sea to Norway) of the deep-sea sponge Phakellia ventilabrum are connected. The analysis comprised ddRADseq derived SNP datasets of 166 individuals collected from 57 sampling stations from 17 different areas, including two Marine Protected Areas, one Special Area of Conservation and other areas with different levels of protection. The 4,017 neutral SNPs used indicated high connectivity and panmixis amongst the majority of areas (Ireland to Norway), spanning ca. 2,500-km at depths of 99-900 m. This was likely due to the presence of strong ocean currents allowing long-distance larval transport, as supported by our migration analysis and by 3D particle tracking modelling. On the contrary, the Cantabrian Sea and Roscoff (France) samples, the southernmost areas in our study, appeared disconnected from the remaining areas, probably due to prevailing current circulation patterns and topographic features, which might be acting as barriers for gene flow. Despite this major genetic break, our results suggest that all protected areas studied are well-connected with each other. Interestingly, analysis of SNPs under selection replicated results obtained for neutral SNPs. The relatively low genetic diversity observed along the study area, though, highlights the potential fragility of this species to changing climates, which might compromise resilience to future threats.
|
|
