Greater sexual reproduction contributes to differences in demography of invasive plants and their noninvasive relatives

An understanding of the demographic processes contributing to invasions would improve our mechanistic understanding of the invasion process and improve the efficiency of prevention and control efforts. However, field comparisons of the demography of invasive and noninvasive species have not previously been conducted. We compared the in situ demography of 17 introduced plant species in St. Louis, Missouri, USA, to contrast the demographic patterns of invasive species with their less invasive relatives across a broad sample of angiosperms. Using herbarium records to estimate spread rates, we found higher maximum spread rates in the landscape for species classified a priori as invasive than for noninvasive introduced species, suggesting that expert classifications are an accurate reflection of invasion rate. Across 17 species, projected population growth was not significantly greater in invasive than in noninvasive introduced species. Among five taxonomic pairs of close relatives, however, four of the invasive species had higher projected population growth rates compared with their noninvasive relative. A Life Table Response Experiment suggested that the greater projected population growth rate of some invasive species relative to their noninvasive relatives was primarily a result of sexual reproduction. The greater sexual reproduction of invasive species is consistent with invaders having a life history strategy more reliant on fecundity than survival and is consistent with a large role of propagule pressure in invasion. Sexual reproduction is a key demographic correlate of invasiveness, suggesting that local processes influencing sexual reproduction, such as enemy escape, might be of general importance. However, the weak correlation of projected population growth with spread rates in the landscape suggests that regional processes, such as dispersal, may be equally important in determining invasion rate

Identification of regulatory variants associated with genetic susceptibility to meningococcal disease.

Non-coding genetic variants play an important role in driving susceptibility to complex diseases but their characterization remains challenging. Here, we employed a novel approach to interrogate the genetic risk of such polymorphisms in a more systematic way by targeting specific regulatory regions relevant for the phenotype studied. We applied this method to meningococcal disease susceptibility, using the DNA binding pattern of RELA - a NF-kB subunit, master regulator of the response to infection - under bacterial stimuli in nasopharyngeal epithelial cells. We designed a custom panel to cover these RELA binding sites and used it for targeted sequencing in cases and controls. Variant calling and association analysis were performed followed by validation of candidate polymorphisms by genotyping in three independent cohorts. We identified two new polymorphisms, rs4823231 and rs11913168, showing signs of association with meningococcal disease susceptibility. In addition, using our genomic data as well as publicly available resources, we found evidences for these SNPs to have potential regulatory effects on ATXN10 and LIF genes respectively. The variants and related candidate genes are relevant for infectious diseases and may have important contribution for meningococcal disease pathology. Finally, we described a novel genetic association approach that could be applied to other phenotypes

Appendix A. Species descriptions for 17 introduced species at Tyson Research Center, St. Louis, Missouri, USA.

Species descriptions for 17 introduced species at Tyson Research Center, St. Louis, Missouri, USA

Appendix C. Demographic matrix models and details of their construction.

Demographic matrix models and details of their construction

Appendix D. Analyses and figures of vital rates, spread rates, and demographic transitions associated with invasiveness for 17 introduced species at Tyson Research Center, St. Louis, Missouri, USA.

Analyses and figures of vital rates, spread rates, and demographic transitions associated with invasiveness for 17 introduced species at Tyson Research Center, St. Louis, Missouri, USA

Supplement 1. R code for demographic analysis of 17 species of introduced plants at Tyson Research Center, St. Louis, Missouri, USA.

<h2>File List</h2><div> <p><a href="CalcLambda.R">CalcLambda.R</a> (MD5: 635e3b831acfadf450918f22b1538146)</p> <p><a href="Demography_LTRE.R">Demography_LTRE.R</a> (MD5: 668e428929aeb183ce205bdf8bffe4b9)</p> <p><a href="Rcode.zip">Rcode.zip</a> (MD5: 125a015bdb847713a460d308f821fa9b)</p> </div><h2>Description</h2><div> <p>CalcLambda.R: This file contains the demographic matrices for 17 species of introduced plants, including calculations for λ.</p> <p>Demography_LTRE.R: This field contains code for the Life Table Response Experiment. This file contains:</p> <p>Sens: a function that calculates sensitivities for a demographic matrix.</p> Rcode.zip: This zip file contains all the above files. </div