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- Al Jewari, Caesar
(author)
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Resolving deep nodes of eukaryote phylogeny
- 2022
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Doctoral thesis (other academic/artistic)abstract
- My thesis aims to solve deep nodes in the eukaryote tree of life (eToL), by developing new data sets and new approaches to analysing them. In paper I, I described a dataset of 76 universal eukaryotic proteins of bacterial descent (euBacs), in order to test the relations among the three main divisions of mitochondriate eukaryotes (Amorphea, Diaphretickes and Discoba). I developed two protocols to identify problematic data. The conJac protocol analyzes data by jackknifing to detect outlier sequences, while conWin uses a sliding window to find sequence fragments of potentially foreign origin. Phylogenetic analyses of the 76 euBacs, with and without conWin or conJac filtering place Discoba as the sister group to Amorphea and Diaphretickes. The results are largely consistent and highly supported under various evolutionary models except for highly complex CAT models. In paper II, I describe a dataset of 198 universal eukaryote proteins of archaeal ancestry (euArcs), which includes the remaining eukaryotes, informally referred to as amitochondriate excavate. These were excluded from the previous study because they lack euBacs. Phylogenetic analyses of the euArc dataset place the amitochondriate excavate as the first three branches of eToL, followed by Discoba, the only mitochondriate excavates, which appear as a sister group to the remaining eukaryotes. I also developed a protocol using predicted protein structures to increase the fitness of the model without inflating the parameter space, allowing me to conduct a series of control analyses and further support the multi-excavate root. In Paper III, I describe a new application of reciprocal-rooting using concatenated sequences, which I then use to test the euArc root. I also developed two sampling protocols unique to this kind of data. The protocols confirm the multi-excavate euArc root, which indicates that eukaryotes arose from an excavate ancestor. Paper IV describes a follow-up on the ConWin results from Paper I. These show moderate to strong support for mosaicism in 16 euBac proteins from diverse metabolic pathways and donor lineages. In summary, this thesis presents a novel root for the eukaryote tree of life. The new root requires revision of fundamental theories of eukaryote evolution including the source and timing of mitochondrial origins. The methods I have developed are applicable to many different kinds of phylogenetic studies, and the new protein structure model should make these analyses faster, more flexible, and more widely available.
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| 2. |
- An, Junghwa, et al.
(author)
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Permanent Genetic Resources added to Molecular Ecology Resources Database 1 October 2009-30 November 2009
- 2010
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In: Molecular Ecology Resources. - : Wiley. - 1755-098X .- 1755-0998. ; 10:2, s. 404-408
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Journal article (peer-reviewed)abstract
- This article documents the addition of 411 microsatellite marker loci and 15 pairs of Single Nucleotide Polymorphism (SNP) sequencing primers to the Molecular Ecology Resources Database. Loci were developed for the following species: Acanthopagrus schlegeli, Anopheles lesteri, Aspergillus clavatus, Aspergillus flavus, Aspergillus fumigatus, Aspergillus oryzae, Aspergillus terreus, Branchiostoma japonicum, Branchiostoma belcheri, Colias behrii, Coryphopterus personatus, Cynogolssus semilaevis, Cynoglossus semilaevis, Dendrobium officinale, Dendrobium officinale, Dysoxylum malabaricum, Metrioptera roeselii, Myrmeciza exsul, Ochotona thibetana, Neosartorya fischeri, Nothofagus pumilio, Onychodactylus fischeri, Phoenicopterus roseus, Salvia officinalis L., Scylla paramamosain, Silene latifo, Sula sula, and Vulpes vulpes. These loci were cross-tested on the following species: Aspergillus giganteus, Colias pelidne, Colias interior, Colias meadii, Colias eurytheme, Coryphopterus lipernes, Coryphopterus glaucofrenum, Coryphopterus eidolon, Gnatholepis thompsoni, Elacatinus evelynae, Dendrobium loddigesii Dendrobium devonianum, Dysoxylum binectariferum, Nothofagus antarctica, Nothofagus dombeyii, Nothofagus nervosa, Nothofagus obliqua, Sula nebouxii, and Sula variegata. This article also documents the addition of 39 sequencing primer pairs and 15 allele specific primers or probes for Paralithodes camtschaticus.
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| 4. |
- Huusko, Johanna M, et al.
(author)
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Whole exome sequencing reveals HSPA1L as a genetic risk factor for spontaneous preterm birth.
- 2018
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In: PLoS genetics. - : Public Library of Science (PLoS). - 1553-7404. ; 14:7
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Journal article (peer-reviewed)abstract
- Preterm birth is a leading cause of morbidity and mortality in infants. Genetic and environmental factors play a role in the susceptibility to preterm birth, but despite many investigations, the genetic basis for preterm birth remain largely unknown. Our objective was to identify rare, possibly damaging, nucleotide variants in mothers from families with recurrent spontaneous preterm births (SPTB). DNA samples from 17 Finnish mothers who delivered at least one infant preterm were subjected to whole exome sequencing. All mothers were of northern Finnish origin and were from seven multiplex families. Additional replication samples of European origin consisted of 93 Danish sister pairs (and two sister triads), all with a history of a preterm delivery. Rare exonic variants (frequency <1%) were analyzed to identify genes and pathways likely to affect SPTB susceptibility. We identified rare, possibly damaging, variants in genes that were common to multiple affected individuals. The glucocorticoid receptor signaling pathway was the most significant (p<1.7e-8) with genes containing these variants in a subgroup of ten Finnish mothers, each having had 2-4 SPTBs. This pathway was replicated among the Danish sister pairs. A gene in this pathway, heat shock protein family A (Hsp70) member 1 like (HSPA1L), contains two likely damaging missense alleles that were found in four different Finnish families. One of the variants (rs34620296) had a higher frequency in cases compared to controls (0.0025 vs. 0.0010, p = 0.002) in a large preterm birth genome-wide association study (GWAS) consisting of mothers of general European ancestry. Sister pairs in replication samples also shared rare, likely damaging HSPA1L variants. Furthermore, in silico analysis predicted an additional phosphorylation site generated by rs34620296 that could potentially affect chaperone activity or HSPA1L protein stability. Finally, in vitro functional experiment showed a link between HSPA1L activity and decidualization. In conclusion, rare, likely damaging, variants in HSPA1L were observed in multiple families with recurrent SPTB.
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| 6. |
- Solé Navais, Pol, et al.
(author)
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Genetic effects on the timing of parturition and links to fetal birth weight.
- 2023
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In: Nature genetics. - 1546-1718. ; 55:4, s. 559-567
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Journal article (peer-reviewed)abstract
- The timing of parturition is crucial for neonatal survival and infant health. Yet, its genetic basis remains largely unresolved. We present a maternal genome-wide meta-analysis of gestational duration (n=195,555), identifying 22 associated loci (24 independent variants) and an enrichment in genes differentially expressed during labor. A meta-analysis of preterm delivery (18,797 cases, 260,246 controls) revealed six associated loci and large genetic similarities with gestational duration. Analysis of the parental transmitted and nontransmitted alleles (n=136,833) shows that 15 of the gestational duration genetic variants act through the maternal genome, whereas 7 act both through the maternal and fetal genomes and 2 act only via the fetal genome. Finally, the maternal effects on gestational duration show signs of antagonistic pleiotropy with the fetal effects on birth weight: maternal alleles that increase gestational duration have negative fetal effects on birth weight. The present study provides insights into the genetic effects on the timing of parturition and the complex maternal-fetal relationship between gestational duration and birth weight.
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| 7. |
- Stone, Graham N., et al.
(author)
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Evidence for widespread cryptic sexual generations in apparently purely asexual Andricus gallwasps
- 2008
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In: Molecular Ecology. - 0962-1083 .- 1365-294X. ; 17:2, s. 652-665
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Journal article (peer-reviewed)abstract
- Oak gallwasps (Hymenoptera, Cynipidae, Cynipini) are one of seven major animal taxa that commonly reproduce by cyclical parthenogenesis (CP). A major question in research on CP taxa is the frequency with which lineages lose their sexual generations, and diversify as purely asexual radiations. Most oak gallwasp species are only known from an asexual generation, and secondary loss of sex has been conclusively demonstrated in several species, particularly members of the holarctic genus Andricus. This raises the possibility of widespread secondary loss of sex in the Cynipini, and of diversification within purely parthenogenetic lineages. We use two approaches based on analyses of allele frequency data to test for cryptic sexual generations in eight apparently asexual European species distributed through a major western palaearctic lineage of the gallwasp genus Andricus. All species showing adequate levels of polymorphism (7/8) showed signatures of sex compatible with cyclical parthenogenesis. We also use DNA sequence data to test the hypothesis that ignorance of these sexual generations (despite extensive study on this group) results from failure to discriminate among known but morphologically indistinguishable sexual generations. This hypothesis is supported: 35 sequences attributed by leading cynipid taxonomists to a single sexual adult morphospecies, Andricus burgundus, were found to represent the sexual generations of at least six Andricus species. We confirm cryptic sexual generations in a total of 11 Andricus species, suggesting that secondary loss of sex is rare in Andricus.
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| 8. |
- Tice, Alexander K., et al.
(author)
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PhyloFisher : A phylogenomic package for resolving eukaryotic relationships
- 2021
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In: PLoS biology. - : Public Library of Science (PLoS). - 1544-9173 .- 1545-7885. ; 19:8
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Journal article (peer-reviewed)abstract
- Phylogenomic analyses of hundreds of protein-coding genes aimed at resolving phylogenetic relationships is now a common practice. However, no software currently exists that includes tools for dataset construction and subsequent analysis with diverse validation strategies to assess robustness. Furthermore, there are no publicly available high-quality curated databases designed to assess deep (>100 million years) relationships in the tree of eukaryotes. To address these issues, we developed an easy-to-use software package, PhyloFisher (https://github.com/TheBrownLab/PhyloFisher), written in Python 3. PhyloFisher includes a manually curated database of 240 protein-coding genes from 304 eukaryotic taxa covering known eukaryotic diversity, a novel tool for ortholog selection, and utilities that will perform diverse analyses required by state-of-the-art phylogenomic investigations. Through phylogenetic reconstructions of the tree of eukaryotes and of the Saccharomycetaceae clade of budding yeasts, we demonstrate the utility of the PhyloFisher workflow and the provided starting database to address phylogenetic questions across a large range of evolutionary time points for diverse groups of organisms. We also demonstrate that undetected paralogy can remain in phylogenomic "single-copy orthogroup" datasets constructed using widely accepted methods such as all vs. all BLAST searches followed by Markov Cluster Algorithm (MCL) clustering and application of automated tree pruning algorithms. Finally, we show how the PhyloFisher workflow helps detect inadvertent paralog inclusions, allowing the user to make more informed decisions regarding orthology assignments, leading to a more accurate final dataset.
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