466 research outputs found
Disruption of gene expression in hybrids of the fire ants Solenopsis invicta and Solenopsis richteri
No full textTranscriptome analysis is a powerful tool for unveiling the distribution and magnitude of genetic incompatibilities between hybridizing taxa. The nature of such incompatibilities is closely associated with the evolutionary histories of the parental species and may differ across tissues and between the sexes. In eusocial insects, the presence of castes that experience divergent selection regimes may result in additional distinct patterns of caste‐specific hybrid incompatibilities. We analysed levels of expression of >14 000 genes in two life stages of each caste in the fire ants Solenopsis invicta and Solenopsis richteri and in their hybrids. We found strong contributions of both developmental stage and caste to gene expression patterns. In contrast, variability in expression was only weakly associated with taxonomic identity, with hybrid scores falling between those of the two parental species. Hybrid incompatibilities were surprisingly modest, with only 32 genes being mis‐expressed, indicating low levels of disruption in gene regulation in hybrids; males and workers each mis‐expressed at least seven times as many genes as queens. Interestingly, homologues of many of the mis‐expressed genes have been implicated in behavioural variation in Drosophila melanogaster. General expression profiles of hybrids consistently were more similar to those of S. richteri than S. invicta, presumably because S. richteri trans‐regulatory elements tend to be dominant and/or because there is an overall bias in the genetic composition of the hybrids towards S. richteri. Altogether, our results suggest that selection acting on each caste may contribute differently to interspecific divergence and speciation in this group of ants
Letter to Alfred L. Shoemaker, February 10, 1948
No full textA handwritten letter from an unknown author addressed to Alfred L. Shoemaker, dated February 10, 1948. Within, the author discusses the Pennsylvania Dutch word for Ash Wednesday, along with traditions associated with this day.https://digitalcommons.ursinus.edu/shoemaker_documents/1118/thumbnail.jp
Evolution of gene expression in fire ants: the effects of developmental stage, caste, and species. Mol Biol Evol
No full textAnts provide remarkable examples of equivalent genotypes developing into divergent and discrete phenotypes. Diploid eggs can develop either into queens, which specialize in reproduction, or workers, which participate in cooperative tasks such as building the nest, collecting food, and rearing the young. In contrast, the differentiation between males and females generally depends upon whether eggs are fertilized, with fertilized (diploid) eggs giving rise to females and unfertilized (haploid) eggs giving rise to males. To obtain a comprehensive picture of the relative contributions of gender (sex), caste, developmental stage, and species divergence to gene expression evolution, we investigated gene expression patterns in pupal and adult queens, workers, and males of two species of fire ants, Solenopsis invicta and S. richteri. Microarray hybridizations revealed that variation in gene expression profiles is influenced more by developmental stage than by caste membership, sex, or species identity. The second major contributor to variation in gene expression was the combination of sex and caste. Although workers and queens share equivalent diploid nuclear genomes, they have highly distinctive patterns of gene expression in both the pupal and the adult stages, as might be expected given their extraordinary level of phenotypic differentiation. Overall, the difference in the proportion of differentially expressed genes was greater between workers and males than between workers and queens or queens and males, consistent with the fact that workers and males share neither gender nor reproductive capability. Moreover, between-species comparisons revealed that the greates
Population genetic structure of the red imported fire ant, Solenopsis invicta, in Taiwan
No full textPopulation genetic analyses reveal host association and genetically distinct populations of social parasite Solenopsis daguerrei (Hymenoptera: Formicidae)
No full textInquiline ant social parasites exploit other ant species for their reproductive benefit because they do not possess a worker caste. Due to their relative rarity in nature, the biology and natural history of inquilines are largely unknown. Likewise, not much research exists that details the close relationship between inquilines and their host(s), and how each organism influences the genetic structure of the other. Here, we conducted a comparative population genetics study to assess patterns of genetic structure within and among populations of inquiline Solenopsis daguerrei and its known fire ant hosts, which includes invasive Solenopsis invicta. Using nuclear and mitochondrial markers, we show that four genetically distinct groups of S. daguerrei likely exist, each with different degrees of host association. Consistent with previous inferences of the inquiline lifestyle, we find that inbreeding is common in S. daguerrei, presumably a result of intranidal mating and restricted dispersal. Results from this study, specifically host association patterns, may inform future biological control strategies to mitigate invasive S. invicta populations.Fil: Dekovich, Allyson. Herbert College Of Agriculture; Estados UnidosFil: Ryan, Sean. Herbert College Of Agriculture; Estados Unidos. Exponent, Inc.; Estados UnidosFil: Bouwma, Andrew. State University of Oregon; Estados UnidosFil: Calcaterra, Luis Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fundación para el Estudio de Especies Invasivas; ArgentinaFil: Silvestre, Rogerio. Universidade Federal Da Grande Dourados; BrasilFil: Staton, Margaret. Herbert College Of Agriculture; Estados UnidosFil: Shoemaker, DeWayne. Herbert College Of Agriculture; Estados Unido
Relaxed selection is a precursor to the evolution of phenotypic plasticity
No full text
Phenotypic plasticity allows organisms to produce alternative phenotypes under different conditions and represents one of the most important ways by which organisms adaptively respond to the environment. However, the relationship between phenotypic plasticity and molecular evolution remains poorly understood. We addressed this issue by investigating the evolution of genes associated with phenotypically plastic castes, sexes, and developmental stages of the fire ant
Solenopsis invicta
. We first determined if genes associated with phenotypic plasticity in
S. invicta
evolved at a rapid rate, as predicted under theoretical models. We found that genes differentially expressed between
S. invicta
castes, sexes, and developmental stages all exhibited elevated rates of evolution compared with ubiquitously expressed genes. We next investigated the evolutionary history of genes associated with the production of castes. Surprisingly, we found that orthologs of caste-biased genes in
S. invicta
and the social bee
Apis mellifera
evolved rapidly in lineages without castes. Thus, in contrast to some theoretical predictions, our results suggest that rapid rates of molecular evolution may not arise primarily as a consequence of phenotypic plasticity. Instead, genes evolving under relaxed purifying selection may more readily adopt new forms of biased expression during the evolution of alternate phenotypes. These results suggest that relaxed selective constraint on protein-coding genes is an important and underappreciated element in the evolutionary origin of phenotypic plasticity.
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Shoemaker is 1986 Vollum Award recipient
No full texthttps://rdc.reed.edu/v1/resources/670ac9f1-49ca-431e-ae94-db71ba35b332/thumb/128.jpgNotes about the winner of the Vollum Award for Distinguished Accomplishment in Science and Technology, David Powell Shoemaker '42, a professor of chemistry emeritus at Oregon State University. He is a textbook author and researcher in crystal structure and transition metal alloys. Howard Vollum '36 is also described
Letter to Alfred L. Shoemaker, December 15, 1949
No full textA handwritten letter from a descendent of Peter Derr addressed to Alfred L. Shoemaker, dated December 15, 1949. Within, the author provides information about folk cures, Harvest Home services and the tradition of serenading newlyweds with loud music.https://digitalcommons.ursinus.edu/shoemaker_documents/1247/thumbnail.jp
Letter From Florence Baver to Alfred L. Shoemaker, August 10, 1960
No full textA typed letter from Florence Baver to Alfred L. Shoemaker, dated August 10, 1960. Within, the author provides various anecdotes from the Lehigh County region, including humor stories and naming lore.https://digitalcommons.ursinus.edu/shoemaker_documents/1276/thumbnail.jp
Reconstructing the global invasion routes of the cabbage white butterfly using citizen science assisted genomics
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