167 research outputs found
Phylogenetic and population genetic differences between sexual and asexual lineages of Neochlamisus leaf beetles
No full textSex is a major challenge to evolutionary theory, because of the apparent paradox of its ubiquity among multicellular eukaryotes with the substantial evolutionary costs associated with it. The past four decades have seen the development of a large and robust collection of hypotheses purporting to explain the benefits of sex and reconcile this paradox, while empirical research testing the predictions of these hypotheses in nature has only begun to gather momentum more recently.
Neochlamisus leaf beetles are one such natural system with great potential for study of the evolutionary tradeoffs of sexuality and asexuality thanks to the prevalence of gynogenetic asexuality within the genus. Gynogenesis is a form of asexual reproduction in which females require insemination to stimulate the development of unreduced eggs into clonal offspring with no paternal genetic contribution. Gynogenesis requires the coexistence of asexual females with females and donor males of the same nominal species, allowing highly controlled comparisons of ecologically and biologically similar sexual and asexual animals.
In this thesis, I present a new mitochondrial DNA dataset consisting of diverged sexual and asexual lineages of Neochlamisus and describe the phylogenetics and patterns of molecular evolution observed in each lineage, with explicit regard to reproductive mode. I then test two a priori predictions of differences in molecular evolution between the sexual and asexual lineages related to reproductive mode. My results are consistent with a higher rate of accumulation of putatively harmful nonsynonymous mutations in the asexual lineage, and with a selective sweep of the mitochondrial genome in the sexual lineage driven by cytoplasmic incompatibility-inducing strains of the intracellular bacterial parasite Wolbachia
Phylogenetic and population genetic differences between sexual and asexual lineages of Neochlamisus leaf beetles
No full textPA-Microphallus_annotated_transcriptome
No full textFasta formatted annotated transcriptome for PA-Microphallus The assembly was generated using Trinity, followed by TransDecoder, then CD-HIT-EST. The transcriptome was annotated using blastx and Blast2GO
PE-Microphallus_annotated_transcriptome
No full textFasta formatted annotated transcriptome for PE-Microphallus The assembly was generated using Trinity, followed by TransDecoder, then CD-HIT-EST. The transcriptome was annotated using blastx and Blast2GO
What is the role of philosophy during a global crisis?
No full textWe are all preoccupied with the Covid-19 global pandemic and justly so. Everyone in the world has lots of little decisions to make, and many are facing life and death situations. What is the use of philosophy in all of this? Is it helpful? Is it a distraction? Can philosophy solve problems or even make a better world? In this wide-ranging discussion, our host Jack Russell Weinstein and guest Susan Neiman explore the absurdity of “trolley problems,” whether we should use the term “evil” to to describe a pandemic, and how we can best support Amazon employees. This episode is both a compelling and accessible philosophical exploration, and a historical artifact that records a unique moment in time. It has been described by one listener as “our most human of episodes.”
Susan Neiman is Director of the Einstein Forum, in Potsdam Germany. She has been a professor of philosophy at Yale and Tel Aviv University, and is the author of numerous books, most recently, Learning from the Germans: Race and the Memory of Evil.https://commons.und.edu/why-radio-archive/1000/thumbnail.jp
Microsatellites_and_primer_data
No full textWe used MISA and Primer3 to identify potential microsatellite loci and predict primer sequences for amplification from our set of orthologous transcripts for both PA-Microphallus and PE-Microphallus. This file contains the locus and primer information (Tables S8 and S9 in manuscript)
Theta_per_transcript_data
No full textWe used Popoolation to estimate Watterson's theta for each transcript in our set of orthologous transcript for 1) PA-Microphallus, and 2) PE-Microphallus
Pairwise_distance_data
No full textWe used Clustal Omega to pairs of orthologous transcripts and calculate Jukes-Cantor-corrected pairwise molecular distance between PA-Microphallus and PE-Microphallu
Fst_per_SNP_data
No full textFst per SNP between PA-Microphallus and PE-Microphallus 1) with both sets of reads mapped to the PA-Microphallus set of orthologous transcripts, and 2)with both sets of reads mapped to the PE-Microphallus set of orthologous transcripts
A tale of two genomes: What drives mitonuclear discordance in asexual lineages of a freshwater snail?
No full textWe use genomic information to tell us stories of evolutionary origins. But what does it mean when different genomes report wildly different accounts of lineage history? This genomic "discordance" can be a consequence of a fascinating suite of natural history and evolutionary phenomena, from the different inheritance mechanisms of nuclear versus cytoplasmic (mitochondrial and plastid) genomes to hybridization and introgression to horizontal transfer. Here, we explore how we can use these distinct genomic stories to provide new insights into the maintenance of sexual reproduction, one of the most important unanswered questions in biology. We focus on the strikingly distinct nuclear versus mitochondrial versions of the story surrounding the origin and maintenance of asexual lineages in Potamopyrgus antipodarum, a New Zealand freshwater snail. While key questions remain unresolved, these data inspire multiple testable hypotheses that can be powerfully applied across a broad range of taxa toward a deeper understanding of the causes and consequences of mitonuclear discordance, the maintenance of sex, and the origin of new asexual lineages
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