Relative genome size variation in the African agroforestry tree Parkia biglobosa (Fabaceae: Caesalpinioideae) and its relation to geography, population genetics and morphology

Variation in genome size and in chromosome number can be linked to genetic, morphological and ecological characteristics, and thus be taxonomically significant. We screened the relative genome size (RGS) and counted the number of mitotic chromosomes in the African agroforestry tree Parkia biglobosa, a widely distributed savannah species that shows conspicuous morphological clinal variation and strong genetic structure, and tested for linkage of RGS variation to geography, leaf morphology, and population genetic variation. An improved protocol for the preparation of chromosomes was developed. The study is based on 58 individuals from 15 populations covering most of the distribution range of the species. We observed differences in RGS among individuals of up to 10.2 %, with some of the individuals differing statistically in RGS from the bulk of screened individuals. Most of the RGS variation was within populations whereas variation was unrelated to any of the tested features of the species. Those chromosome numbers which could be exactly established were invariable 2n = 2x = 26. In conclusion, there was no evidence from the karyological data for structured intra-specific taxonomic heterogeneity.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Potentilla_puberula_Alonso-Marcos_et_al_ecological_variables_population_level_2018

Appendix 1. Description of 238 populations of Potentilla puberula sampled between 1999 and 2015 in the Eastern European Alps. Geographical and collection information, number of sampled individuals (N) and cytotype composition, as well as source of flow cytometric data (FCM) are given. Topographic parameters (elevation, in m a.s.l.; inclination and aspect, in degrees), a variable representing the land use intensity, an index of vegetation density (NDVI) and bioclimatic descriptors (Bio01-Bio19, from the Chelsea Climate database) are noted per each population. Please see README for citation information. Soil parameters are reported for 121 populations visited in 2015, including pH, carbonate (CO3--), organic carbon (Corg) and nitrogen content (Ntot; in g/kg), cation exchange capacity (CEC), cations (in mmol/kg), and base saturation (BS, in %). Abbreviations: AT Andreas Tribsch; CD Christoph Dobeš; FDN Flavia Domizia Nardi; HAM Henar Alonso-Marcos; JAH Julian Ananda Haider; JP Juraj Paule; RS Roswitha Schmickl; SSc Susanne Scheffknecht; SSt Simon Stifter; TW Thomas Wilhalm

Potentilla_puberula_Alonso-Marcos_et_al_Flow_Cytometry_2018

Appendix 2. Flow cytometric data of 1,878 individuals from 115 populations collected between 1999 and 2013. Identification, population and used device for the analyses are indicated. Used internal standards are provided: either Solanum pseudocapsicum (Sps) or Lycopersicon esculentum cv. Stupické polní tyčkové rané (Sly). Since several individuals from the same population were pooled in each measurement (the number of individuals included in each measurement is provided), more than one sample peak was found in some measurements. For each of these peaks (Peak1, Peak2, Peak3 and Peak4) and for the standard, the count of particles, the mean fluorescence and the coefficient of variation are reported. The sample/standard ratio was used to infer the ploidy level of each peak. The number of individuals (N_Peak1 to N_Peak4) per each determined ploidy level (Ploidy_Peak1 to Ploidy_Peak4) are given

Data from: Difference in reproductive mode rather than ploidy explains niche differentiation in sympatric sexual and apomictic populations of Potentilla puberula

Apomicts tend to have larger geographical distributional ranges and to occur in ecologically more extreme environments than their sexual progenitors. However, the expression of apomixis is typically linked to polyploidy. Thus, it is a priori not clear whether intrinsic effects related to the change in the reproductive mode or rather in the ploidy drive ecological differentiation. We used sympatric sexual and apomictic populations of Potentilla puberula to test for ecological differentiation. To distinguish the effects of reproductive mode and ploidy on the ecology of cytotypes, we compared the niches (i) of sexuals (tetraploids) and autopolyploid apomicts (penta-, hepta- and octoploids) and (ii) of the three apomictic cytotypes. We based comparisons on a ploidy screen of 238 populations along a latitudinal transect through the Eastern European Alps and associated bioclimatic, soil and topographic data. Sexual tetraploids preferred primary habitats at drier, steeper, more south-oriented slopes, while apomicts mostly occurred in human-made habitats with higher water availability. Contrariwise, we found no or only marginal ecological differentiation among the apomictic higher ploids. Based on the pronounced ecological differences found between sexuals and apomicts, in addition to the lack of niche differentiation among cytotypes of the same reproductive mode, we conclude that reproductive mode rather than ploidy is the main driver of the observed differences. Moreover, we compared our system with others from the literature, to stress the importance of identifying alternative confounding effects (such as hybrid origin). Finally, we underline the relevance of studying ecological parthenogenesis in sympatry, to minimise the effects of differential migration abilitie

A robotic multidimensional directed evolution approach applied to fluorescent voltage reporters

© 2018 The Author(s). We developed a new way to engineer complex proteins toward multidimensional specifications using a simple, yet scalable, directed evolution strategy. By robotically picking mammalian cells that were identified, under a microscope, as expressing proteins that simultaneously exhibit several specific properties, we can screen hundreds of thousands of proteins in a library in just a few hours, evaluating each along multiple performance axes. To demonstrate the power of this approach, we created a genetically encoded fluorescent voltage indicator, simultaneously optimizing its brightness and membrane localization using our microscopy-guided cell-picking strategy. We produced the high-performance opsin-based fluorescent voltage reporter Archon1 and demonstrated its utility by imaging spiking and millivolt-scale subthreshold and synaptic activity in acute mouse brain slices and in larval zebrafish in vivo. We also measured postsynaptic responses downstream of optogenetically controlled neurons in C. elegans