Véronique Delesalle - Academia.edu (original) (raw)

Papers by Véronique Delesalle

Microbiology Resource Announcements, 2021

Lolalove, a B4 subcluster soil bacteriophage of Mycobacterium smegmatis , was isolated in Charles... more Lolalove, a B4 subcluster soil bacteriophage of Mycobacterium smegmatis , was isolated in Charleston, South Carolina. It possesses a 71,111-bp linear double-stranded DNA (dsDNA) genome with 99 protein-coding genes and a GC content of 68.9%. Whole-genome BLASTn alignments indicate high sequence identity to the related B4 subcluster M. smegmatis phages BrownCNA, Mithril, and Hangman.

American Midland Naturalist, 1992

-The weevil Listronotus appendiculatus lays eggs on immature inflorescences of Sagittaria latifol... more -The weevil Listronotus appendiculatus lays eggs on immature inflorescences of Sagittaria latifolia, which, in the study area, may be male, monoecious or female. The weevil lays the same numbers of eggs on male as on monoecious inflorescences, and in both cases the larvae create a strong vertical gradient in the success of male flowers, with basal flowers more successful in presenting pollen. The monoecious inflorescences have female flowers in the basal positions that are the safest for male flowers. The interference of these female flowers with male success is low, however, because the number of female flowers per monoecious inflorescence is small. The weevil lays many fewer eggs on female than on male or monoecious inflorescences, and the potential for damage to female success is much lower on female than on monoecious inflorescences. The male parts of a monoecious inflorescence seem to "attract" egg laying, which subsequently interferes with the female success of that inflorescence. In these ways each gender on a monoecious inflorescence interferes with the escape of the other gender from herbivory. This pattern of herbivory may help to select for the unisexuality found in the taxon.

Viruses

Bacteriophages (phages) are the most numerous entities on Earth, but we have only scratched the s... more Bacteriophages (phages) are the most numerous entities on Earth, but we have only scratched the surface of describing phage diversity. We isolated seven Bacillus subtilis phages from desert soil in the southwest United States and then sequenced and characterized their genomes. Comparative analyses revealed high nucleotide and amino acid similarity between these seven phages, which constitute a novel subcluster. Interestingly, the tail fiber and lysin genes of these phages seem to come from different origins and carry out slightly different functions. These genes were likely acquired by this subcluster of phages via horizontal gene transfer. In conjunction with host range assays, our data suggest that these phages are adapting to hosts with different cell walls.

Microbiology resource announcements, Nov 4, 2021

Although crucial in shaping bacterial communities, few bacteriophages of the phyllosphere have be... more Although crucial in shaping bacterial communities, few bacteriophages of the phyllosphere have been described. We provide genome data for two Myoviridae phages, AH04 and AH06, isolated on Erwinia billingiae strains. AH04 shares limited genetic similarity with previously described phages, while AH06 shares over 75% similarity with various Erwinia phages. D espite their relevance to bacterial population dynamics on plants (1-5), bacteriophages that infect plant pathogens are poorly described. Here, we describe two phages isolated on Erwinia billingiae strains, themselves isolated from the leaves of horse chestnut trees (Aesculus hippocastanum; Sapindaceae) from the same location in Oxford, UK (1-3). The bacterial strains were classified based on sequencing of 800 bp of the 16S rRNA region and the top BLASTn hits associated with a sequence (E value, ,10 210) (1). Each phage was single-plaque purified at least three times on its focal host and amplified by overnight culturing in 10 ml King's broth and 100 ml of isolation bacteria (1). The cultured lysate was filtered (pore size, 0.45 mm), and following the Promega Wizard PCR Preps DNA purification system kit protocol (no. 7170), phage DNA was extracted by the Koskella lab. DNA samples were sent to North Carolina State University's Genomic Science Laboratory for sequencing. Libraries were prepared using the Illumina TruSeq Nano DNA library prep kit following the manufacturer's protocol. Sequencing was conducted on the Illumina MiSeq platform, using a v3 150 SE flow cell. For each sample, 150-bp reads were assembled into one contig using the GS v2.9 de novo assembler, with .200Â coverage (Table 1); the quality of the consensus contig was verified using Consed v29 (6, 7). The genome ends were determined to be circularly permuted through analysis with PAUSE and PhageTerm (8, 9). The sequences were imported into DNA Master v5.22.22 (10) to map the open reading frames. Putative genes were called based on Glimmer v3.0 and GeneMark v2.5 algorithms (11, 12). Putative functions of the gene products were predicted using BLAST v2.12 (13) and HHpred (14). For the BLASTp matches, an E value below 10 25 was required to assign a function. For the HHpred matches, a high probability (.85%), substantial coverage (.50%), and low E value (,10 25) were required. The presence of tRNA genes was verified through the Webbased program ARAGORN (15). Default settings were used in all analyses. Both phages have similar GC contents and relatively large genomes, with more than 290 genes, including one tRNA gene for AH04 (Table 1). Based on a BLASTn search of the nucleotide (nt) database restricted to phages (taxid 10699, 10662, and 10744), both phages are likely Myoviridae. AH04 shows limited nucleotide similarity (15 to 25%) to three Myoviridae phages isolated on different Proteobacteria hosts (Table 1). AH06 exhibits greater nucleotide similarity (.75%) to a number of Myoviridae Erwinia phages (Table 1). As is typical of Myoviridae genomes (16, 17), there is little conservation of genome organization, and only 19 to 20% of genes could be assigned a function. Both genomes include three endolysins, including one with a family 19 chitinase domain-the biggest gene in each genome (7,215 and 6,678 bp, respectively, in AH04 and AH06), which is impressively long, given the average gene length in these phages (851 and 773 bp) and the published average phage gene length of 616 bp (18). Based on sequencing of DNA extracted from

Molecular Ecology, Jan 18, 2023

The rate and trajectory of evolution in an obligate parasite is critically dependent on those of ... more The rate and trajectory of evolution in an obligate parasite is critically dependent on those of its host(s). Adaptation to a genetically homogeneous host population should theoretically result in specialization, while adaptation to an evolving host population (i.e., coevolution) can result in various outcomes including diversification, range expansion, and/or local adaptation. For viruses of bacteria (bacteriophages, or phages), our understanding of how evolutionary history of the bacterial host(s) impacts viral genotypic and phenotypic evolution is currently limited. In this study, we used whole genome sequencing and two different metrics of phage impacts to compare the genotypes and phenotypes of lytic phages that had either coevolved with or were repeatedly passaged on an unchanging (ancestral) strain of the phytopathogen Pseudomonas syringae. Genomes of coevolved phages had more mutations than those of phages passaged on a constant host, and most mutations were in genes encoding phage tail‐associated proteins. Phages from both passaging treatments shared some phenotypic outcomes, including range expansion and divergence across replicate populations, but coevolved phages were more efficient at reducing population growth (particularly of sympatric coevolved hosts). Genotypic similarity correlated with infectivity profile similarity in coevolved phages, but not in phages passaged on the ancestral host. Overall, while adaptation to either host type (coevolving or ancestral) led to divergence in phage tail proteins and infectivity patterns, coevolution led to more rapid molecular changes that increased bacterial killing efficiency and had more predictable effects on infectivity range. Together, these results underscore the important role of hosts in driving viral evolution and in shaping the genotype–phenotype relationship.

Viruses, Sep 23, 2022

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Genome Announcements, Jun 30, 2016

Five bacteriophages that infect the Rhodobacter capsulatus strain YW1 were isolated from stream w... more Five bacteriophages that infect the Rhodobacter capsulatus strain YW1 were isolated from stream water near Bloomington, Illinois, USA. Two distinct genome types are represented in the newly isolated bacteriophages. These genomes are different from other bacteriophage genomes previously described.

Journal of Evolutionary Biology, Nov 13, 2007

Among plants, pairs of selfing vs. outcrossing sister taxa provide interesting systems in which t... more Among plants, pairs of selfing vs. outcrossing sister taxa provide interesting systems in which to test predictions concerning the magnitude and direction of temporal changes in sex allocation. Although resource availability typically declines towards the end of the growing season for annual taxa, temporal changes in mating opportunities depend on mating system and should change less in selfing taxa. Consequently, given that the pollen:ovule (P:O) ratio of flowers reflects the investment in (and potential fitness pay‐off due to) male vs. female function, we predicted that the P:O ratio should also be less variable among and within selfers than in closely related outcrossers. To test these predictions, we measured temporal changes in sex allocation in multiple field populations of two pairs of sister taxa in the annual flowering plant genus Clarkia (Onagraceae). In the outcrossing Clarkia unguiculata and the selfing Clarkia exilis, ovule production declined similarly from early to late buds, whereas pollen production remained constant or increased in the outcrosser but remained constant or decreased in the selfer. Consequently, the P:O ratio increased within unguiculata populations but marginally increased or stayed constant in exilis populations. In all populations of the selfing Clarkia xantiana spp. parviflora and the outcrossing C. x. spp. xantiana, both ovule and pollen production per flower declined over time. The effects of these declines on the P:O ratio, however, differed between subspecies. In each xantiana population, the mean P:O ratio did not differ between early and late flowers, although individuals varied greatly in the direction and magnitude of phenotypic change. By contrast, parviflora populations differed in the mean direction of temporal change in the P:O ratio. We found little evidence to support our initial predictions that the P:O ratio of the selfing taxa will consistently vary less than in outcrossing taxa.

Journal of Microbiology & Biology Education, 2017

Numerous national reports have called for reforming laboratory courses so that all students exper... more Numerous national reports have called for reforming laboratory courses so that all students experience the research process. In response, many course-based research experiences (CREs) have been developed and implemented. Research on the impact of these CREs suggests that student benefits can be similar to those of traditional apprentice-model research experiences. However, most assessments of CREs have been in individual courses at individual institutions or across institutions using the same CRE model. Furthermore, which structures and components of CREs result in the greatest student gains is unknown. We explored the impact of different CRE models in different contexts on student self-reported gains in understanding, skills, and professional development using the Classroom Undergraduate Research Experience (CURE) survey. Our analysis included 49 courses developed and taught at seven diverse institutions. Overall, students reported greater gains for all benefits when compared with ...

and is deposited in the University Library to be made available to borrowers under rules of the L... more and is deposited in the University Library to be made available to borrowers under rules of the Library. Brief quotations from this dissertation are allowable without special permission, provided that accurate acknowledgment of source is made. Requests for permission for extended quotation from or reproduction of this manuscript in whole or in part may be granted by the head of the major department or the Dean of the Graduate College when in his or her judgment the proposed use of the material is in the interests of scholarship. In all other instances, however, permission must be obtained from the author.

International Journal of Plant Sciences, 1992

... Male and female func-Manuscript received March 1991; revised manuscript received September 19... more ... Male and female func-Manuscript received March 1991; revised manuscript received September 1991. Address for correspondence and reprints: Veronique A. De-lesalle, Department of Biology, Emory University, Atlanta, Georgia 30322. ...

Behavioural Processes, 1986

Delesalle, V.A., 1986. Division of parental care and reproductive success in the Zebra finch (Tae... more Delesalle, V.A., 1986. Division of parental care and reproductive success in the Zebra finch (Taenioel@a guttata). Behav.-Processes, 12: l-22. Variation in reproductive success among pairs of Zebra finches (Taenioeyea guttata), _-_ bred in captivity under time-rather than energy-limited conditions, arose primarily because of differences in number of clutches per reproductive bout. Division of parental care between mates during the time-constrained incubation phase, rather than the fledging phase, affected their fitness and future behavior. Pairs where the males assumed a greater fraction of the pooled incubation time were more likely to breed together again than pairs where males did not share in this activity as equally. In addition, males remated with familiar mates increased their time investment in incubation.

Genome announcements, Jan 26, 2016

American Journal of Botany, 1994

One hypothesis for the evolution of maleness in plants postulates the following: male plants appe... more One hypothesis for the evolution of maleness in plants postulates the following: male plants appear that have re-allocated resources from female parts into a larger number of male flowers, creating a larger floral display. Pollinators respond "dramatically" to the increased display, driving the spread of males in the population (Bawa, K. S., 1980, Annual Review of Ecology and Systematics 1 1: 15-40). To test this, we measured the total number of flowers and the size of male displays in dioecious Sagittaria latifolia and monoecious S. australis. We also measured how fast visitors arrived at "target" flowers in the displays. Then we used the Cox Model, a failure time analysis procedure, to analyze the relationship between visitor arrival and display size. We found that male display sizes were somewhat larger in the dioecious than the monoecious plants, but this was due to more compressed blooming rather than to a larger total number of flowers. The visitors to both plants were similar arrays of generalist bees. Visitors did not show the predicted "dramatic" response, however, but rather a plateauing response to larger display sizes, so our results do not support the hypothesis. Reviewing the literature, we found no reports of the "dramatic" response the hypothesis asserts. Instead, relative insensitivity to display size is the rule.

Microbiology Resource Announcements

Subcluster L3 bacteriophage Finnry was isolated from soil collected in Charleston, South Carolina... more Subcluster L3 bacteriophage Finnry was isolated from soil collected in Charleston, South Carolina, using Mycobacterium smegmatis mc 2 155 as a host. The genome of this temperate siphovirus is 75,632 bp long (130 predicted protein-coding genes, 9 tRNAs, and no transfer-messenger RNAs), and BLASTn alignment revealed 99.86% identity with the genome of L3 mycobacteriophage Samty.

eLife, 2015

The bacteriophage population is large, dynamic, ancient, and genetically diverse. Limited genomic... more The bacteriophage population is large, dynamic, ancient, and genetically diverse. Limited genomic information shows that phage genomes are mosaic, and the genetic architecture of phage populations remains ill-defined. To understand the population structure of phages infecting a single host strain, we isolated, sequenced, and compared 627 phages of Mycobacterium smegmatis. Their genetic diversity is considerable, and there are 28 distinct genomic types (clusters) with related nucleotide sequences. However, amino acid sequence comparisons show pervasive genomic mosaicism, and quantification of inter-cluster and intra-cluster relatedness reveals a continuum of genetic diversity, albeit with uneven representation of different phages. Furthermore, rarefaction analysis shows that the mycobacteriophage population is not closed, and there is a constant influx of genes from other sources. Phage isolation and analysis was performed by a large consortium of academic institutions, illustrating ...