scholarly journals From the Clinical Mycology Laboratory: New Species and Changes in Fungal Taxonomy and Nomenclature

2018 ◽  
Vol 4 (4) ◽  
pp. 138 ◽  
Author(s):  
Nathan Wiederhold ◽  
Connie Gibas
Keyword(s):  
New Species ◽  
Dna Sequences ◽  
Phenotypic Traits ◽  
Fungal Taxonomy ◽  
Nomenclature System ◽  
Morphologic Characteristics ◽  
Dual Nomenclature ◽  
Clinical Literature ◽  
Clinical Mycology ◽  
The Impact

Fungal taxonomy is the branch of mycology by which we classify and group fungi based on similarities or differences. Historically, this was done by morphologic characteristics and other phenotypic traits. However, with the advent of the molecular age in mycology, phylogenetic analysis based on DNA sequences has replaced these classic means for grouping related species. This, along with the abandonment of the dual nomenclature system, has led to a marked increase in the number of new species and reclassification of known species. Although these evaluations and changes are necessary to move the field forward, there is concern among medical mycologists that the rapidity by which fungal nomenclature is changing could cause confusion in the clinical literature. Thus, there is a proposal to allow medical mycologists to adopt changes in taxonomy and nomenclature at a slower pace. In this review, changes in the taxonomy and nomenclature of medically relevant fungi will be discussed along with the impact this may have on clinicians and patient care. Specific examples of changes and current controversies will also be given.

scholarly journals Reciprocal hemizygosity analysis reveals that the Saccharomyces cerevisiae CGI121 gene affects lag time duration in synthetic grape must

2021 ◽  
Author(s):  
Runze Li ◽  
Rebecca C Deed
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Low Temperatures ◽  
Lag Time ◽  
Lag Phase ◽  
Phenotypic Traits ◽  
Time Duration ◽  
Phase Duration ◽  
Grape Must ◽  
The Impact ◽  
Reciprocal Hemizygosity Analysis

Abstract It is standard practice to ferment white wines at low temperatures (10-18 °C). However, low temperatures increase fermentation duration and risk of problem ferments, leading to significant costs. The lag duration at fermentation initiation is heavily impacted by temperature; therefore, identification of Saccharomyces cerevisiae genes influencing fermentation kinetics is of interest for winemaking. We selected 28 S. cerevisiae BY4743 single deletants, from a prior list of open reading frames (ORFs) mapped to quantitative trait loci (QTLs) on chromosomes VII and XIII, influencing the duration of fermentative lag time. Five BY4743 deletants, Δapt1, Δcgi121, Δclb6, Δrps17a, and Δvma21, differed significantly in their fermentative lag duration compared to BY4743 in synthetic grape must (SGM) at 15 °C, over 72 h. Fermentation at 12.5 °C for 528 h confirmed the longer lag times of BY4743 Δcgi121, Δrps17a, and Δvma21. These three candidate ORFs were deleted in S. cerevisiae RM11-1a and S288C to perform single reciprocal hemizygosity analysis (RHA). RHA hybrids and single deletants of RM11-1a and S288C were fermented at 12.5 °C in SGM and lag time measurements confirmed that the S288C allele of CGI121 on chromosome XIII, encoding a component of the EKC/KEOPS complex, increased fermentative lag phase duration. Nucleotide sequences of RM11-1a and S288C CGI121 alleles differed by only one synonymous nucleotide, suggesting that intron splicing, codon bias, or positional effects might be responsible for the impact on lag phase duration. This research demonstrates a new role of CGI121 and highlights the applicability of QTL analysis for investigating complex phenotypic traits in yeast.

Systematic benchmark of ancient DNA read mapping

2021 ◽  
Author(s):  
Adrien Oliva ◽  
Raymond Tobler ◽  
Alan Cooper ◽  
Bastien Llamas ◽  
Yassine Souilmi
Keyword(s):  
Ancient Dna ◽  
Dna Sequences ◽  
Population Genetic ◽  
Reference Genome ◽  
Population Data ◽  
Human Populations ◽  
Current Standard ◽  
Read Mapping ◽  
Reference Bias ◽  
The Impact

Abstract The current standard practice for assembling individual genomes involves mapping millions of short DNA sequences (also known as DNA ‘reads’) against a pre-constructed reference genome. Mapping vast amounts of short reads in a timely manner is a computationally challenging task that inevitably produces artefacts, including biases against alleles not found in the reference genome. This reference bias and other mapping artefacts are expected to be exacerbated in ancient DNA (aDNA) studies, which rely on the analysis of low quantities of damaged and very short DNA fragments (~30–80 bp). Nevertheless, the current gold-standard mapping strategies for aDNA studies have effectively remained unchanged for nearly a decade, during which time new software has emerged. In this study, we used simulated aDNA reads from three different human populations to benchmark the performance of 30 distinct mapping strategies implemented across four different read mapping software—BWA-aln, BWA-mem, NovoAlign and Bowtie2—and quantified the impact of reference bias in downstream population genetic analyses. We show that specific NovoAlign, BWA-aln and BWA-mem parameterizations achieve high mapping precision with low levels of reference bias, particularly after filtering out reads with low mapping qualities. However, unbiased NovoAlign results required the use of an IUPAC reference genome. While relevant only to aDNA projects where reference population data are available, the benefit of using an IUPAC reference demonstrates the value of incorporating population genetic information into the aDNA mapping process, echoing recent results based on graph genome representations.

scholarly journals Codon harmonization reduces amino acid misincorporation in bacterially expressed P. falciparum proteins and improves their immunogenicity

AMB Express ◽  
2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Neeraja Punde ◽  
Jennifer Kooken ◽  
Dagmar Leary ◽  
Patricia M. Legler ◽  
Evelina Angov
Keyword(s):  
Protein Structure ◽  
Amino Acid ◽  
Codon Usage ◽  
Dna Sequences ◽  
Structural Integrity ◽  
Host Cells ◽  
Loss Of Function ◽  
Species Specific ◽  
And Function ◽  
The Impact

Abstract Codon usage frequency influences protein structure and function. The frequency with which codons are used potentially impacts primary, secondary and tertiary protein structure. Poor expression, loss of function, insolubility, or truncation can result from species-specific differences in codon usage. “Codon harmonization” more closely aligns native codon usage frequencies with those of the expression host particularly within putative inter-domain segments where slower rates of translation may play a role in protein folding. Heterologous expression of Plasmodium falciparum genes in Escherichia coli has been a challenge due to their AT-rich codon bias and the highly repetitive DNA sequences. Here, codon harmonization was applied to the malarial antigen, CelTOS (Cell-traversal protein for ookinetes and sporozoites). CelTOS is a highly conserved P. falciparum protein involved in cellular traversal through mosquito and vertebrate host cells. It reversibly refolds after thermal denaturation making it a desirable malarial vaccine candidate. Protein expressed in E. coli from a codon harmonized sequence of P. falciparum CelTOS (CH-PfCelTOS) was compared with protein expressed from the native codon sequence (N-PfCelTOS) to assess the impact of codon usage on protein expression levels, solubility, yield, stability, structural integrity, recognition with CelTOS-specific mAbs and immunogenicity in mice. While the translated proteins were expected to be identical, the translated products produced from the codon-harmonized sequence differed in helical content and showed a smaller distribution of polypeptides in mass spectra indicating lower heterogeneity of the codon harmonized version and fewer amino acid misincorporations. Substitutions of hydrophobic-to-hydrophobic amino acid were observed more commonly than any other. CH-PfCelTOS induced significantly higher antibody levels compared with N-PfCelTOS; however, no significant differences in either IFN-γ or IL-4 cellular responses were detected between the two antigens.

scholarly journals Predicting the Impact of Describing New Species on Phylogenetic Patterns

2019 ◽  
Vol 1 (1) ◽  
Author(s):  
D C Blackburn ◽  
G Giribet ◽  
D E Soltis ◽  
E L Stanley
Keyword(s):  
New Species ◽  
Phylogenetic Trees ◽  
Branch Length ◽  
Length Variation ◽  
Tree Shape ◽  
Branch Lengths ◽  
Taxonomic History ◽  
Ecological Patterns ◽  
The Impact ◽  
Incomplete Sampling

Abstract Although our inventory of Earth’s biodiversity remains incomplete, we still require analyses using the Tree of Life to understand evolutionary and ecological patterns. Because incomplete sampling may bias our inferences, we must evaluate how future additions of newly discovered species might impact analyses performed today. We describe an approach that uses taxonomic history and phylogenetic trees to characterize the impact of past species discoveries on phylogenetic knowledge using patterns of branch-length variation, tree shape, and phylogenetic diversity. This provides a framework for assessing the relative completeness of taxonomic knowledge of lineages within a phylogeny. To demonstrate this approach, we use recent large phylogenies for amphibians, reptiles, flowering plants, and invertebrates. Well-known clades exhibit a decline in the mean and range of branch lengths that are added each year as new species are described. With increased taxonomic knowledge over time, deep lineages of well-known clades become known such that most recently described new species are added close to the tips of the tree, reflecting changing tree shape over the course of taxonomic history. The same analyses reveal other clades to be candidates for future discoveries that could dramatically impact our phylogenetic knowledge. Our work reveals that species are often added non-randomly to the phylogeny over multiyear time-scales in a predictable pattern of taxonomic maturation. Our results suggest that we can make informed predictions about how new species will be added across the phylogeny of a given clade, thus providing a framework for accommodating unsampled undescribed species in evolutionary analyses.

The impact of obesity on oocytes: evidence for lipotoxicity mechanisms

2012 ◽  
Vol 24 (1) ◽  
pp. 29 ◽  
Author(s):  
Linda L.-Y. Wu ◽  
Robert J. Norman ◽  
Rebecca L. Robker
Keyword(s):  
Endoplasmic Reticulum ◽  
Endoplasmic Reticulum Stress ◽  
Mitochondrial Dysfunction ◽  
Intracytoplasmic Sperm Injection ◽  
Oocyte Quality ◽  
Early Embryo ◽  
Pregnancy Rates ◽  
Clinical Literature ◽  
The Impact

Obesity can have detrimental effects on pregnancy rates in natural conceptions and also in women undergoing IVF or intracytoplasmic sperm injection (ICSI). This review summarises the most recent clinical literature investigating whether obesity impacts oocyte quality and early embryo growth. In other tissues, obesity leads to lipotoxicity responses including endoplasmic reticulum stress, mitochondrial dysfunction and apoptosis. Recent reports indicate that lipotoxicity is a mechanism by which obesity may impact oocyte quality.

scholarly journals Nothing in (sponge) biology makes sense – except when based on holotypes

2015 ◽  
Vol 96 (2) ◽  
pp. 305-311 ◽  
Author(s):  
Dirk Erpenbeck ◽  
Merrick Ekins ◽  
Nicole Enghuber ◽  
John N.A. Hooper ◽  
Helmut Lehnert ◽  
...  
Keyword(s):  
New Species ◽  
Reference Material ◽  
Species Identification ◽  
Dna Sequences ◽  
Morphological Plasticity ◽  
Morphological Characters ◽  
Molecular Techniques ◽  
Reference Sequences ◽  
Species Descriptions ◽  
Preservation History

Sponge species are infamously difficult to identify for non-experts due to their high morphological plasticity and the paucity of informative morphological characters. The use of molecular techniques certainly helps with species identification, but unfortunately it requires prior reference sequences. Holotypes constitute the best reference material for species identification, however their usage in molecular systematics and taxonomy is scarce and frequently not even attempted, mostly due to their antiquity and preservation history. Here we provide case studies in which we demonstrate the importance of using holotype material to answer phylogenetic and taxonomic questions. We also demonstrate the possibility of sequencing DNA fragments out of century-old holotypes. Furthermore we propose the deposition of DNA sequences in conjunction with new species descriptions.

scholarly journals Benchmarking DNA barcodes: an assessment using available primate sequences

Genome ◽  
2006 ◽  
Vol 49 (7) ◽  
pp. 851-854 ◽  
Author(s):  
Mehrdad Hajibabaei ◽  
Gregory AC Singer ◽  
Donal A Hickey
Keyword(s):  
New Species ◽  
Cryptic Species ◽  
Dna Barcoding ◽  
Species Identification ◽  
Dna Sequences ◽  
Phylogenetic Relationships ◽  
Primate Species ◽  
Dna Barcodes ◽  
Global Biodiversity ◽  
Efficient Sequence

DNA barcoding has been recently promoted as a method for both assigning specimens to known species and for discovering new and cryptic species. Here we test both the potential and the limitations of DNA barcodes by analysing a group of well-studied organisms—the primates. Our results show that DNA barcodes provide enough information to efficiently identify and delineate primate species, but that they cannot reliably uncover many of the deeper phylogenetic relationships. Our conclusion is that these short DNA sequences do not contain enough information to build reliable molecular phylogenies or define new species, but that they can provide efficient sequence tags for assigning unknown specimens to known species. As such, DNA barcoding provides enormous potential for use in global biodiversity studies.Key words: DNA barcoding, species identification, primate, biodiversity.

A new species of Chlorociboria (Helotiales, Ascomycota) on herbaceous stems from China

Phytotaxa ◽  
2017 ◽  
Vol 312 (1) ◽  
pp. 111
Author(s):  
HUAN-DI ZHENG ◽  
WEN-YING ZHUANG
Keyword(s):  
New Species ◽  
Dna Sequences ◽  
Internal Transcribed Spacer ◽  
Phylogenetic Analyses ◽  
Large Subunit ◽  
Central China ◽  
Nuclear Ribosomal Dna ◽  
Light Blue ◽  
Ectal Excipulum ◽  
A New Species

A new species, namely Chlorociboria herbicola, is discovered on herbaceous stems in central China. Morphologically, the new fungus is distinctive by the combination of light blue-green apothecia, rectangular cells in ectal excipulum, and elongate-ellipsoidal ascospores with rounded ends. Phylogenetic analyses of the internal transcribed spacer and large subunit of nuclear ribosomal DNA sequences confirm its ascription in Chlorociboria and distinction from the known species of the genus.

scholarly journals Rhamnella intermedia (Rhamnaceae), a new evergreen species from southwest Guangxi

PhytoKeys ◽  
2020 ◽  
Vol 159 ◽  
pp. 115-126
Author(s):  
Zhiqiang Lu ◽  
Yongshuai Sun
Keyword(s):  
New Species ◽  
Related Species ◽  
Principal Component ◽  
Phenotypic Traits ◽  
Evergreen Species ◽  
Closely Related Species ◽  
Field Investigations ◽  
Sequence Variations ◽  
Dried Fruit ◽  
Nuclear Its

Rhamnella intermedia, a new evergreen species from southwest Guangxi, is described and illustrated in this study. This species is similar to R. brachycarpa by the size and ratio of length to width of dried fruit and seeds, by which it differs from R. rubrinervis and R. tonkinensis. However, it differs from R. brachycarpa by rarely mucronate seed apices, larger ratio of length to width of leaves, leaf apices acuminate to long acuminate, shorter leaf petioles, and longer fruiting pedicels. Principal component analysis based on phenotypic traits further recognised three separated groups. Rhamnella rubrinervis and R. tonkinensis were clustered into one group; the other two groups represented R. brachycarpa and two Guangxi populations, respectively. Furthermore, phylogenetic analysis of nuclear ITS sequence variations highly supported that the two Guangxi populations represented an independent evolutionary lineage and were closest to R. rubrinervis. Four fixed nucleotide sites were found and were different from R. rubrinervis. However, besides the differentiated traits in seeds and fruit, densely pilose young branches also separated them from R. rubrinervis. In addition, during our field investigations, none of the three closely related species were found at locations where this new species was distributed. Therefore, this new species, based on the two Guangxi populations, is named R. intermedia. The key to four closely related species is also presented.

scholarly journals First Anthomyzidae (Diptera) from China: a new genus, six new species and new records

2018 ◽  
Vol 58 (1) ◽  
pp. 35-76 ◽  
Author(s):  
Jindřich Roháček
Keyword(s):  
New Species ◽  
East Asia ◽  
Dna Sequences ◽  
New Genus ◽  
New Records ◽  
Molecular Barcoding ◽  
The Family ◽  
First Time

The family Anthomyzidae (Diptera: Acalyptrata) is recorded from China for the first time based on 11 species, 6 of them new to science. A distinctive new genus Marshallya gen. nov. is described, based on single peculiar species, M. platythorax sp. nov. (both sexes) from Sichuan. Other new species, viz. Amygdalops sevciki sp. nov. (Hainan I.) (both sexes), Epischnomyia tkoci sp. nov. (Sichuan) (male only), Anthomyza ornata sp. nov. (Sichuan) (female only), Anthomyza sulphurea sp. nov. (Yunnan) (both sexes) and Arganthomyza hyperseta sp. nov. (Shaanxi) (male only) are described and illustrated in detail. Male-female association of two Amygdalops species is clarified by means of molecular barcoding and the female of A. bisinus Roháček, 2008 is correctly identifi ed and described. Relationships of all these taxa are discussed. Five species, viz. Amygdalops bisinus (Hainan I.), Epischnomyia merzi Roháček, 2009, Anthomyza cuneata Roháček, 1987, Anthomyza trifurca Sueyoshi & Roháček, 2003 (all from Sichuan) and Arganthomyza versitheca Roháček, 2009 (Shaanxi, Sichuan) are new additions to the Chinese fauna of Anthomyzidae. DNA sequences of the barcoding region of COI have been obtained for 3 species, Amygdalops bisinus, Amygdalops sevciki and Marshallya platythorax. Biology and distribution of all 11 species are discussed. First photographs of living Anthomyzidae from East Asia are presented. Based on knowledge of Anthomyzidae from neighbouring areas the diversity of the Chinese fauna of the family is estimated to include 50-60 species.

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