Publications by authors named "Katherine LoBuglio"

7 Publications

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Rhodoxanthin synthase from honeysuckle; a membrane diiron enzyme catalyzes the multistep conversation of β-carotene to rhodoxanthin.

Sci Adv 2020 Apr 22;6(17):eaay9226. Epub 2020 Apr 22.

DSM Nutritional Products, 60 Westview St, Lexington, MA 02421, USA.

Rhodoxanthin is a vibrant red carotenoid found across the plant kingdom and in certain birds and fish. It is a member of the atypical retro class of carotenoids, which contain an additional double bond and a concerted shift of the conjugated double bonds relative to the more widely occurring carotenoid pigments, and whose biosynthetic origins have long remained elusive. Here, we identify LHRS ( hydroxylase rhodoxanthin synthase), a variant β-carotene hydroxylase (BCH)-type integral membrane diiron enzyme that mediates the conversion of β-carotene into rhodoxanthin. We identify residues that are critical to rhodoxanthin formation by LHRS. Substitution of only three residues converts a typical BCH into a multifunctional enzyme that mediates a multistep pathway from β-carotene to rhodoxanthin via a series of distinct oxidation steps in which the product of each step becomes the substrate for the next catalytic cycle. We propose a biosynthetic pathway from β-carotene to rhodoxanthin.
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http://dx.doi.org/10.1126/sciadv.aay9226DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7176425PMC
April 2020

Lost and found: the Bermudan Donadinia seaveri found in North America, with comments on its juniper associates.

Mycologia 2018 Jan-Feb;110(1):215-221

a Farlow Reference Library and Herbarium and the Department of Organismic and Evolutionary Biology , Harvard University , 22 Divinity Ave., Cambridge , Massachusetts 02138.

Collections of a species referred to Sarcosomataceae (Pezizomycetes) from eastern North America were studied both morphologically and using nuc rDNA internal transcribed spacer (ITS) region (ITS1-5.8S-ITS2 = ITS) and approximately 800 bp from the 5' region of the nuc 28S rDNA (28S) to construct a phylogeny. The analyses indicate that these collections are Donadinia seaveri, a species previously known only from Bermuda. Because the associated tree, Juniperus bermudiana, has declined as a result of insect attack, it was thought that D. seaveri might be extinct. This work indicates that it is not extinct but is present in eastern North America. The species is described, new distributional records are given, and its association with the genus Juniperus is discussed.
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http://dx.doi.org/10.1080/00275514.2017.1409052DOI Listing
December 2018

Bulgariella pulla, a Leotiomycete of uncertain placement, with an uncommon type of ascus opening.

Mycologia 2017 14;109(6):900-911. Epub 2018 Mar 14.

a Farlow Herbarium, Harvard University , 22 Divinity Avenue, Cambridge , Massachusetts 02138.

Bulgariella pulla (Leotiomycetes) is redescribed with the addition of characters of the ascus, spores, and habitat that were previously unconsidered. The ascus dehiscence mechanism in Bulgariella is unusual among Leotiomycetes. In this genus, asci lack a pore and open by splitting to form valves. Phylogenetic analyses of partial sequences of translation elongation factor 1-α (TEF1-α), the second largest subunit of RNA polymerase II (RPB2), and the 18S and 28S nuc rRNA genes determined that Bulgariella belongs within Leotiomycetes but without conclusive assignment to an order or family. A comparison of the nuc rDNA internal transcribed spacers 1 and 2 plus the 5.8S gene (ITS) determined that Bulgariella isolates from the USA, Norway, and Sweden had 100% sequence similarity, and an isolate from Chile had 99.3% similarity with these isolates. These results support the proposition that these collections represent a single species, B. pulla. Bulgariella sphaerospora, a more recently described species, is confirmed as conspecific with B. pulla.
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http://dx.doi.org/10.1080/00275514.2017.1418590DOI Listing
November 2018

Placement of the genus Angelina within Rhytismatales and observations of Angelina rufescens.

Mycologia 2014 Jan-Feb;106(1):154-62

Farlow Herbarium of Harvard University, 22 Divinity Avenue, Cambridge, Massachusetts 02138.

Angelina rufescens is placed within the core clade of Rhytismatales (Leotiomycetes, Pezizomycotina, Ascomycota) based on analysis of LSU and mtSSU rDNA. The only species in the genus, it produces distinctive ascomata that reoccur annually on wood and on the remains of its own previous fructifications, forming dense conglomerations of interlocking longitudinally elongated apothecia with gray hymenia. Known collections and references of A. rufescens indicate that it is endemic to eastern and central United States. Morphological and cultural characters are described with notes on ascomata development. No mitospores were observed in field collections or in culture. Lectotypes are designated for Hysterium rufescens and its synonym Ascobolus conglomeratus. Angelina rufescens is illustrated here for the first time in the taxonomic literature.
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http://dx.doi.org/10.3852/13-174DOI Listing
April 2014

A Glomerella species phylogenetically related to Colletotrichum acutatum on Norway maple in Massachusetts.

Mycologia 2008 Sep-Oct;100(5):710-5

Harvard University Herbaria, Cambridge, Massachusetts 02138, USA.

A fungus isolated from Norway maple (Acer platanoides) in the Boston, Massachusetts, area was determined to be a species of Glomerella, the teleomorph of Colletotrin chum acutatum. Pure cultures of the fungus were obtained from discharged ascospores from perithecia in leaf tissue. This fungus was determined to be homothallic based on the observation of perithecial development in cultures of single-spore isolates grown on minimal salts media and with sterile toothpicks. A morphological and molecular analysis was conducted to determine the taxonomic position of this fungus. Parsimony analyses of a combined nucleotide dataset of the ITS and LSU rDNA region, and of the D1-D2 LSU rDNA region, indicated that this species has phylogenetic affinities with Colletotrichum acutatum, C. acutatum f. sp. pineum, C. lupini, C. phormii and G. miyabeana. These results are significant because C. acutatum has not been reported on Acer platanoides. In addition the consistent presence of perithecia on leaf tissue and in culture is unusual for Colletotrichum, suggesting that the teleomorphic state is important in the life cycle of this fungus.
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http://dx.doi.org/10.3852/07-192DOI Listing
December 2008

Evolutionary relationships of the cup-fungus genus Peziza and Pezizaceae inferred from multiple nuclear genes: RPB2, beta-tubulin, and LSU rDNA.

Mol Phylogenet Evol 2005 Jul 22;36(1):1-23. Epub 2005 Apr 22.

Harvard University Herbaria, Cambridge, MA 02138, USA.

To provide a robust phylogeny of Pezizaceae, partial sequences from two nuclear protein-coding genes, RPB2 (encoding the second largest subunit of RNA polymerase II) and beta-tubulin, were obtained from 69 and 72 specimens, respectively, to analyze with nuclear ribosomal large subunit RNA gene sequences (LSU). The three-gene data set includes 32 species of Peziza, and 27 species from nine additional epigeous and six hypogeous (truffle) pezizaceous genera. Analyses of the combined LSU, RPB2, and beta-tubulin data set using parsimony, maximum likelihood, and Bayesian approaches identify 14 fine-scale lineages within Pezizaceae. Species of Peziza occur in eight of the lineages, spread among other genera of the family, confirming the non-monophyly of the genus. Although parsimony analyses of the three-gene data set produced a nearly completely resolved strict consensus tree, with increased confidence, relationships between the lineages are still resolved with mostly weak bootstrap support. Bayesian analyses of the three-gene data, however, show support for several more inclusive clades, mostly congruent with Bayesian analyses of RPB2. No strongly supported incongruence was found among phylogenies derived from the separate LSU, RPB2, and beta-tubulin data sets. The RPB2 region appeared to be the most informative single gene region based on resolution and clade support, and accounts for the greatest number of potentially parsimony informative characters within the combined data set, followed by the LSU and the beta-tubulin region. The results indicate that third codon positions in beta-tubulin are saturated, especially for sites that provide information about the deeper relationships. Nevertheless, almost all phylogenetic signal in beta-tubulin is due to third positions changes, with almost no signal in first and second codons, and contribute phylogenetic information at the "fine-scale" level within the Pezizaceae. The Pezizaceae is supported as monophyletic in analyses of the three-gene data set, but its sister-group relationships is not resolved with support. The results advocate the use of RPB2 as a marker for ascomycete phylogenetics at the inter-generic level, whereas the beta-tubulin gene appears less useful.
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http://dx.doi.org/10.1016/j.ympev.2005.03.010DOI Listing
July 2005

Recombination and genetic differentiation in the mycorrhizal fungus Cenococcum geophilum Fr.

Mycologia 2002 Sep-Oct;94(5):772-80

Department of Plant and Microbial Biology, 111 Koshland Hall, University of California, Berkeley, California 94720-3102.

Population genetic analyses of the mycorrhizal fungus Cenococcum geophilum were conducted to test for a clonal or recombining population structure. Multilocus genotypes based on polymorphisms in 9 loci, identified in this study by PCR-SSCP techniques, were obtained for two populations. Genotypic variation occurred on a fine scale because unique genotypes were identified at most every transect point, and in some cases occurred even within one soil sample (equivalent to about a 500 mL volume). The largest genet observed occurred over a 30 meter transect space. The two population genetic methods employed to distinguish between clonality and recombination, (1) Index of Association; and (2) "Parsimony Tree Length Permutation Test" (PTLPT), could not reject the null hypothesis of recombination in either population. Wright's Fst, as estimated by theta, was used to examine gene flow between the two populations based on allele frequencies. Two of the nine loci had theta values that were not significantly different from what one would expect for the null hypothesis of panmixia. However, the other seven loci were consistent with reduced gene flow. The theta value for the Fisher combined probability (combining all 9 loci) was significant and indicated that there was genetic differentiation between these two populations.
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October 2012