Editorial : Solanaceae VII: Biology, Genetics, and Evolution

Non peer reviewe

Repeated evolution of a morphological novelty: a phylogenetic analysis of the inflated fruiting calyx in the Physalideae tribe (Solanaceae)

Premise of the Study The evolution of novel fruit morphologies has been integral to the success of angiosperms. The inflated fruiting calyx, in which the balloon‐like calyx swells to completely surround the fruit, has evolved repeatedly across angiosperms and is postulated to aid in protection and dispersal. We investigated the evolution of this trait in the tomatillos and their allies (Physalideae, Solanaceae). Methods The Physalideae phylogeny was estimated using four regions (ITS, LEAFY, trnL‐F, waxy) with maximum likelihood (ML) and Bayesian inference. Under the best‐fitting ML model of trait evolution, we estimated ancestral states along with the numbers of gains and losses of fruiting calyx accrescence and inflation with Bayesian stochastic mapping. Also, phylogenetic signal in calyx morphology was examined with two metrics (parsimony score and Fritz and Purvis's D). Key Results Based on our well‐resolved and densely sampled phylogeny, we infer that calyx evolution has proceeded in a stepwise and directional fashion, from non‐accrescent to accrescent to inflated. In total, we inferred 24 gains of accrescence, 24 subsequent transitions to a fully inflated calyx, and only two reversals. Despite this lability, fruiting calyx accrescence and inflation showed strong phylogenetic signal. Conclusions Our phylogeny greatly improves the resolution of Physalideae and highlights the need for taxonomic work. The comparative analyses reveal that the inflated fruiting calyx has evolved many times and that the trajectory toward this phenotype is generally stepwise and irreversible. These results provide a strong foundation for studying the genetic and developmental mechanisms responsible for the repeated origins of this charismatic fruit trait. </div

How to approach the study of syndromes in macroevolution and ecology.

Funder: National Park Foundation; Id: http://dx.doi.org/10.13039/100001261Funder: National Council for Scientific Research and TechniquesFunder: Mt Cuba CenterSyndromes, wherein multiple traits evolve convergently in response to a shared selective driver, form a central concept in ecology and evolution. Recent work has questioned the existence of some classic syndromes, such as pollination and seed dispersal syndromes. Here, we discuss some of the major issues that have afflicted research into syndromes in macroevolution and ecology. First, correlated evolution of traits and hypothesized selective drivers is often relied on as the only evidence for adaptation of those traits to those hypothesized drivers, without supporting evidence. Second, the selective driver is often inferred from a combination of traits without explicit testing. Third, researchers often measure traits that are easy for humans to observe rather than measuring traits that are suited to testing the hypothesis of adaptation. Finally, species are often chosen for study because of their striking phenotypes, which leads to the illusion of syndromes and divergence. We argue that these issues can be avoided by combining studies of trait variation across entire clades or communities with explicit tests of adaptive hypotheses and that taking this approach will lead to a better understanding of syndrome-like evolution and its drivers

It takes a village - overcoming gender-biased mentorship in academia

Effective mentoring implies a two-way relationship in which mentees obtain benefits from the knowledge and training provided by mentors, and mentors gain the possibility of contemplating and learning new perspectives, of self-evaluating their roles and, in consequence, growing as professionals. Mentorship relationships cannot be separated from cultural and societal backgrounds. Thus, they often reflect systemic biases requiring active effort to counteract institutional inequities. Such efforts, particularly when formalized as programs, expand training opportunities for both mentors and mentees. Mentorship networks, in which multiple mentor-mentee relationships are involved, therefore increase collective performance by magnifying resources. Importantly, mentorship exceeds the relationships of students and their direct supervisors (often reflected in co-authorship in publications), and in fact, mentors are often purposely picked outside the direct publication network. A recent large data analysis by AlShebli et al. (2020) showed results of presumed “mentor-protege” relationships after mining millions of coauthor pairs in publications over time, suggesting gender-insensitive changes in institutional mentorship policies based on value-skewed academic success. Because mentorship engages a broader sense of community in academia, mentorship outcomes cannot be quantified solely by the impact of publications

Functional profiling of the Saccharomyces cerevisiae genome

Determining the effect of gene deletion is a fundamental approach to understanding gene function. Conventional genetic screens exhibit biases, and genes contributing to a phenotype are often missed. We systematically constructed a nearly complete collection of gene-deletion mutants (96% of annotated open reading frames, or ORFs) of the yeast Saccharomyces cerevisiae. DNA sequences dubbed 'molecular bar codes' uniquely identify each strain, enabling their growth to be analysed in parallel and the fitness contribution of each gene to be quantitatively assessed by hybridization to high-density oligonucleotide arrays. We show that previously known and new genes are necessary for optimal growth under six well-studied conditions: high salt, sorbitol, galactose, pH 8, minimal medium and nystatin treatment. Less than 7% of genes that exhibit a significant increase in messenger RNA expression are also required for optimal growth in four of the tested conditions. Our results validate the yeast gene-deletion collection as a valuable resource for functional genomics.Journal ArticleResearch Support, Non-U.S. Gov'tSCOPUS: ar.jinfo:eu-repo/semantics/publishe