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1.
Cell ; 176(4): 928-943.e22, 2019 02 07.
Article in English | MEDLINE | ID: mdl-30712874

ABSTRACT

Understanding the molecular programs that guide differentiation during development is a major challenge. Here, we introduce Waddington-OT, an approach for studying developmental time courses to infer ancestor-descendant fates and model the regulatory programs that underlie them. We apply the method to reconstruct the landscape of reprogramming from 315,000 single-cell RNA sequencing (scRNA-seq) profiles, collected at half-day intervals across 18 days. The results reveal a wider range of developmental programs than previously characterized. Cells gradually adopt either a terminal stromal state or a mesenchymal-to-epithelial transition state. The latter gives rise to populations related to pluripotent, extra-embryonic, and neural cells, with each harboring multiple finer subpopulations. The analysis predicts transcription factors and paracrine signals that affect fates and experiments validate that the TF Obox6 and the cytokine GDF9 enhance reprogramming efficiency. Our approach sheds light on the process and outcome of reprogramming and provides a framework applicable to diverse temporal processes in biology.


Subject(s)
Cellular Reprogramming/genetics , Gene Expression Profiling/methods , Single-Cell Analysis/methods , Animals , Cell Differentiation/genetics , Cells, Cultured , Embryonic Stem Cells/metabolism , Fibroblasts/metabolism , Gene Expression , Gene Expression Regulation, Developmental/genetics , Induced Pluripotent Stem Cells/metabolism , Mice , Sequence Analysis, RNA/methods , Transcription Factors/metabolism
2.
Mol Ecol ; 33(5): e17268, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38230514

ABSTRACT

Ecological divergence due to habitat difference plays a prominent role in the formation of new species, but the genetic architecture during ecological speciation and the mechanism underlying phenotypic divergence remain less understood. Two wild ancestors of rice (Oryza rufipogon and Oryza nivara) are a progenitor-derivative species pair with ecological divergence and provide a unique system for studying ecological adaptation/speciation. Here, we constructed a high-resolution linkage map and conducted a quantitative trait locus (QTL) analysis of 19 phenotypic traits using an F2 population generated from a cross between the two Oryza species. We identified 113 QTLs associated with interspecific divergence of 16 quantitative traits, with effect sizes ranging from 1.61% to 34.1% in terms of the percentage of variation explained (PVE). The distribution of effect sizes of QTLs followed a negative exponential, suggesting that a few genes of large effect and many genes of small effect were responsible for the phenotypic divergence. We observed 18 clusters of QTLs (QTL hotspots) on 11 chromosomes, significantly more than that expected by chance, demonstrating the importance of coinheritance of loci/genes in ecological adaptation/speciation. Analysis of effect direction and v-test statistics revealed that interspecific differentiation of most traits was driven by divergent natural selection, supporting the argument that ecological adaptation/speciation would proceed rapidly under coordinated selection on multiple traits. Our findings provide new insights into the understanding of genetic architecture of ecological adaptation and speciation in plants and help effective manipulation of specific genes or gene cluster in rice breeding.


Subject(s)
Oryza , Oryza/genetics , Plant Breeding , Chromosome Mapping , Phenotype , Quantitative Trait Loci/genetics
3.
Proc Natl Acad Sci U S A ; 118(2)2021 01 12.
Article in English | MEDLINE | ID: mdl-33372148

ABSTRACT

The HIV-1 matrix protein p17 (p17) is a pleiotropic molecule impacting on different cell types. Its interaction with many cellular proteins underlines the importance of the viral protein as a major determinant of human specific adaptation. We previously showed the proangiogenic capability of p17. Here, by integrating functional analysis and receptor binding, we identify a functional epitope that displays molecular mimicry with human erythropoietin (EPO) and promotes angiogenesis through common beta chain receptor (ßCR) activation. The functional EPO-like epitope was found to be present in the matrix protein of HIV-1 ancestors SIV originated in chimpanzees (SIVcpz) and gorillas (SIVgor) but not in that of HIV-2 and its ancestor SIVsmm from sooty mangabeys. According to biological data, evolution of the EPO-like epitope showed a clear differentiation between HIV-1/SIVcpz-gor and HIV-2/SIVsmm branches, thus highlighting this epitope on p17 as a divergent signature discriminating HIV-1 and HIV-2 ancestors. P17 is known to enhance HIV-1 replication. Similarly to other ßCR ligands, p17 is capable of attracting and activating HIV-1 target cells and promoting a proinflammatory microenvironment. Thus, it is tempting to speculate that acquisition of an epitope on the matrix proteins of HIV-1 ancestors capable of triggering ßCR may have represented a critical step to enhance viral aggressiveness and early human-to-human SIVcpz/gor dissemination. The hypothesis that the p17/ßCR interaction and ßCR abnormal stimulation may also play a role in sustaining chronic activation and inflammation, thus marking the difference between HIV-1 and HIV-2 in term of pathogenicity, needs further investigation.


Subject(s)
Erythropoietin/genetics , HIV Antigens/metabolism , HIV-1/metabolism , gag Gene Products, Human Immunodeficiency Virus/metabolism , Cells, Cultured , Epitopes/immunology , Erythropoietin/metabolism , Evolution, Molecular , HIV Antigens/genetics , HIV Seropositivity , HIV-1/genetics , HIV-2 , Humans , Molecular Mimicry , Simian Immunodeficiency Virus , gag Gene Products, Human Immunodeficiency Virus/genetics
4.
Cult Med Psychiatry ; 48(3): 634-654, 2024 Sep.
Article in English | MEDLINE | ID: mdl-38909336

ABSTRACT

Cultural beliefs influence the perceived cause, methods of diagnosis and treatment of mental illnesses. A qualitative study was conducted among traditional health practitioners (THPs) in the Harry Gwala District Municipality to further explore this influence. Purposive sampling assisted in the recruitment of 31 participants (9 males and 22 females). The four key themes this study investigated in relation to mental illness included its causes, methods of diagnosis, common symptoms observed and treatment approaches used by THPs, and the system of patient management. Culturally, mental illness was reported to be caused by witchcraft and an ancestral calling in this study. Mental illness was predominantly diagnosed by spiritual intervention which included divination through consultation with the ancestors, familial background, burning of incense which can also be part of communicating with the ancestors and through examining the patient. The common symptoms included aggression, hallucination and unresponsiveness. Prevalent modes of treatment included the use of a medicinal concoction and performing cultural rituals where ancestors and other spirits were assumed influential. The duration of the treatment process was dependent on guidance from the ancestors. Most causal aspects of mental illness from diagnosis to treatment seemed to be influenced by cultural beliefs and ancestors.


Subject(s)
Medicine, African Traditional , Mental Disorders , Qualitative Research , Humans , Male , Female , Mental Disorders/ethnology , Mental Disorders/therapy , Mental Disorders/diagnosis , Adult , South Africa/ethnology , Middle Aged , Culture , Traditional Medicine Practitioners
5.
Chemistry ; 29(21): e202203580, 2023 Apr 13.
Article in English | MEDLINE | ID: mdl-36693799

ABSTRACT

It is intriguing how a mixture of organic molecules survived the prebiotic UV fluxes and evolved into the actual genetic building blocks. Scientists are trying to shed light on this issue by synthesizing nucleic acid monomers and their analogues under prebiotic Era-like conditions and by exploring their excited state dynamics. To further add to this important body of knowledge, this study discloses new insights into the photophysical properties of protonated isoguanine, an isomorph of guanine, using steady-state and femtosecond broadband transient absorption spectroscopies, and quantum mechanical calculations. Protonated isoguanine decays in ultrafast time scales following 292 nm excitation, consistently with the barrierless paths connecting the bright S1 (ππ*) state with different internal conversion funnels. Complementary calculations for neutral isoguanine predict similar photophysical properties. These results demonstrate that protonated isoguanine can be considered photostable in contrast to protonated guanine, which exhibits 40-fold longer excited state lifetimes.

6.
BMC Womens Health ; 23(1): 160, 2023 04 04.
Article in English | MEDLINE | ID: mdl-37016349

ABSTRACT

BACKGROUND: The prevalence of Human Papillomavirus (HPV) infection in the general population is widely known, however, there are still few studies related to this infection in minority groups, Thus, the objective is to analyze the frequency of human papillomavirus and associated factors in quilombola and gypsy women. METHODS: Cross-sectional research with 145 quilombola and gypsy women from Caxias, Maranhão. Two Pap smear collections were performed and a questionnaire with 46 questions was applied between January, 2020 and March, 2021. Descriptive analysis and Odds Ratio with 95% confidence interval were performed. The research was approved by the ethics committee. RESULTS: There were 09 cases of atypia. The frequency of human papillomavirus was 41.37%, with a higher risk in quilombolas 55 (91.70%). Multiple infections were prevalent (53%) with high-risk genotypes 21 (35%). Types 16 and 18 together accounted for 42.85% of cases. CONCLUSIONS: The frequency of human papillomavirus infection was higher than those recorded in the Northeast and Brazil, and therefore type 16 predominated. Due to limitations, the virus lineages and sublineages were not evaluated. Quilombola women had a higher rate of infection than gypsies.


Subject(s)
Papillomavirus Infections , Roma , Uterine Cervical Dysplasia , Uterine Cervical Neoplasms , Female , Humans , Cross-Sectional Studies , Human Papillomavirus Viruses , Papillomaviridae/genetics , Papillomavirus Infections/epidemiology , Uterine Cervical Dysplasia/epidemiology , Uterine Cervical Neoplasms/epidemiology , Minority Groups , Adolescent , Adult , Middle Aged , Brazil
7.
Molecules ; 27(4)2022 Feb 10.
Article in English | MEDLINE | ID: mdl-35208973

ABSTRACT

Cyanuric acid is a triazine derivative that has been identified from reactions performed under prebiotic conditions and has been proposed as a prospective precursor of ancestral RNA. For cyanuric acid to have played a key role during the prebiotic era, it would have needed to survive the harsh electromagnetic radiation conditions reaching the Earth's surface during prebiotic times (≥200 nm). Therefore, the photostability of cyanuric acid would have been crucial for its accumulation during the prebiotic era. To evaluate the putative photostability of cyanuric acid in water, in this contribution, we employed density functional theory (DFT) and its time-dependent variant (TD-DFT) including implicit and explicit solvent effects. The calculations predict that cyanuric acid has an absorption maximum at ca. 160 nm (7.73 eV), with the lowest-energy absorption band extending to ca. 200 nm in an aqueous solution and exhibiting negligible absorption at longer wavelengths. Excitation of cyanuric acid at 160 nm or longer wavelengths leads to the population of S5,6 singlet states, which have ππ* character and large oscillator strengths (0.8). The population reaching the S5,6 states is expected to internally convert to the S1,2 states in an ultrafast time scale. The S1,2 states, which have nπ* character, are predicted to access a conical intersection with the ground state in a nearly barrierless fashion (ca. ≤ 0.13 eV), thus efficiently returning the population to the ground state. Furthermore, based on calculated spin-orbit coupling elements of ca. 6 to 8 cm-1, the calculations predict that intersystem crossing to the triplet manifold should play a minor role in the electronic relaxation of cyanuric acid. We have also calculated the vertical ionization energy of cyanuric acid at 8.2 eV, which predicts that direct one-photon ionization of cyanuric acid should occur at ca. 150 nm. Collectively, the quantum-chemical calculations predict that cyanuric acid would have been highly photostable under the solar radiation conditions reaching the Earth's surface during the prebiotic era in an aqueous solution. Of relevance to the chemical origin of life and RNA-first theories, these observations lend support to the idea that cyanuric acid could have accumulated in large quantities during the prebiotic era and thus strengthens its candidature as a relevant prebiotic nucleobase.


Subject(s)
Models, Chemical , Photochemical Processes , Triazines/chemistry , Drug Stability
8.
Semin Cell Dev Biol ; 91: 31-44, 2019 07.
Article in English | MEDLINE | ID: mdl-29331210

ABSTRACT

Craniofacial muscles, muscles that move the eyes, control facial expression and allow food uptake and speech, have long been regarded as a variation on the general body muscle scheme. However, evidence has accumulated that the function of head muscles, their developmental anatomy and the underlying regulatory cascades are distinct. This article reviews the key aspects of craniofacial muscle and muscle stem cell formation and discusses how this differs from the trunk programme of myogenesis; we show novel RNAseq data to support this notion. We also trace the origin of head muscle in the chordate ancestors of vertebrates and discuss links with smooth-type muscle in the primitive chordate pharynx. We look out as to how the special properties of head muscle precursor and stem cells, in particular their competence to contribute to the heart, could be exploited in regenerative medicine.


Subject(s)
Eye/embryology , Head/embryology , Mesoderm/embryology , Muscle, Skeletal/embryology , Animals , Cholinergic Neurons/cytology , Cholinergic Neurons/metabolism , Eye/innervation , Gene Expression Regulation, Developmental , Head/innervation , Mesoderm/cytology , Muscle Development/genetics , Muscle, Skeletal/cytology , Muscle, Skeletal/innervation , Myoblasts/cytology , Myoblasts/metabolism , Vertebrates/embryology , Vertebrates/genetics
9.
BMC Genet ; 21(1): 104, 2020 09 14.
Article in English | MEDLINE | ID: mdl-32928105

ABSTRACT

BACKGROUND: Prebreeding in plants is the activity designed to identify useful characteristics from wild germplasm and its integration in breeding programs. Prebreeding aims to introduce new variation into the populations of a species of interest. Pedigree analysis is a valuable tool for evaluation of variation in genebanks where pedigree maps are used to visualize and describe population structure and variation within these populations. Margot Forde Germplasm Centre (MFGC) is New Zealand's national forage genebank and holds a collection of ~ 75 species of the genus Trifolium, of which only a dozen have been taken through prebreeding programs. The main objective of this study was to construct pedigree maps and analyse patterns of relatedness for seven minor Trifolium species accessions contained at the MFGC. These species are Trifolium ambiguum, Trifolium arvense, Trifolium dubium, Trifolium hybridum, Trifolium medium, Trifolium subterraneum and the Trifolium repens x Trifolium occidentale interspecific hybrids. We present a history of Trifolium spp. prebreeding in New Zealand and inform breeders of possible alternative forage species to use. RESULTS: Pedigree data from accessions introduced between 1950 and 2016 were used and filtered based on breeding activity. Kinship levels among Trifolium spp. remained below 8% and no inbreeding was found. Influential ancestors that contributed largely to populations structure were identified. The Australian cultivar 'Monaro' had a strong influence over the whole population of accessions in T. ambiguum. T. subterraneum and T. repens x T. occidentale had the largest number of generations (3). T. ambiguum and T. medium had the highest cumulative kinship across the decades. CONCLUSIONS: We conclude that there are high levels of diversity in the seven Trifolium spp. studied. However, collection and prebreeding efforts must be strengthened to maximize utilization and bring useful genetic variation.


Subject(s)
Genetics, Population , Pedigree , Plant Breeding , Trifolium/genetics , Genetic Variation , Genome, Plant , Inbreeding , New Zealand , Trifolium/classification
10.
Afr Archaeol Rev ; 37(3): 481-485, 2020.
Article in English | MEDLINE | ID: mdl-32863520

ABSTRACT

The significant economic and health impacts of the COVID-19 pandemic have forced archaeologists to consider the concept of resilience in the present day, as it relates to their profession, students, research projects, cultural heritage, and the livelihoods and well-being of the communities with a stake in the sites they study. The global crisis presents an opportunity to cement archaeological practice in a foundation of community building. We can learn from the ancestors, razana, how investing in community-social networks at different scales-makes us more resilient to crises. In so doing, we can improve the quality and equity of the science we produce and ensure relevant outcomes for living communities and future generations.


Les impacts économiques et de santé considérables de la pandémie COVID-19 obligent les archéologues à considérer le concept de résilience à l'heure actuelle, en ce qui concerne leur profession, leurs étudiants, leurs projets de recherche, le patrimoine culturel et les modes de vie et le bien-être des communautés ayant un intérêt dans les sites qu'ils étudient. La crise mondiale offre une opportunité de cimenter la pratique archéologique dans un fondement communautaire. Nous pouvons apprendre de nos ancêtres, les razana, que le fait d'investir dans des réseaux communautaires et sociaux à différentes échelles nous rend plus résistants aux crises. Ce faisant, nous pouvons améliorer la qualité et l'équité de la science que nous produisons et garantir des résultats pertinents pour les communautés vivantes et les générations futures.

11.
Biol Chem ; 400(3): 367-381, 2019 02 25.
Article in English | MEDLINE | ID: mdl-30763032

ABSTRACT

For evolutionary studies, but also for protein engineering, ancestral sequence reconstruction (ASR) has become an indispensable tool. The first step of every ASR protocol is the preparation of a representative sequence set containing at most a few hundred recent homologs whose composition determines decisively the outcome of a reconstruction. A common approach for sequence selection consists of several rounds of manual recompilation that is driven by embedded phylogenetic analyses of the varied sequence sets. For ASR of a geranylgeranylglyceryl phosphate synthase, we additionally utilized FitSS4ASR, which replaces this time-consuming protocol with an efficient and more rational approach. FitSS4ASR applies orthogonal filters to a set of homologs to eliminate outlier sequences and those bearing only a weak phylogenetic signal. To demonstrate the usefulness of FitSS4ASR, we determined experimentally the oligomerization state of eight predecessors, which is a delicate and taxon-specific property. Corresponding ancestors deduced in a manual approach and by means of FitSS4ASR had the same dimeric or hexameric conformation; this concordance testifies to the efficiency of FitSS4ASR for sequence selection. FitSS4ASR-based results of two other ASR experiments were added to the Supporting Information. Program and documentation are available at https://gitlab.bioinf.ur.de/hek61586/FitSS4ASR.


Subject(s)
Alkyl and Aryl Transferases/genetics , Software , Alkyl and Aryl Transferases/isolation & purification , Alkyl and Aryl Transferases/metabolism , Amino Acid Sequence , Cloning, Molecular , Evolution, Molecular , Phylogeny , Protein Engineering , Time Factors
12.
Adv Exp Med Biol ; 1137: 61-91, 2019.
Article in English | MEDLINE | ID: mdl-31183820

ABSTRACT

In the previous chapter we were able to automatically process text by recognizing a limited set of entities. This chapter will introduce the world of semantics, and present step-by-step examples to retrieve and enhance text and data processing by using semantics. The goal is to equip the reader with the basic set of skills to explore semantic resources that are nowadays available using simple shell script commands.


Subject(s)
Electronic Data Processing , Information Storage and Retrieval , Semantics
13.
Int J Mol Sci ; 20(15)2019 Aug 05.
Article in English | MEDLINE | ID: mdl-31387284

ABSTRACT

Polyploid Saccharum with complex genomes hindered the progress of sugarcane improvement, while their chloroplast genomes are much smaller and simpler. Chloroplast (cp), the vital organelle, is the site of plant photosynthesis, which also evolves other functions, such as tolerance to environmental stresses. In this study, the cp genome of two sugarcane ancestors Saccharum officinarum and S. spontaneum were sequenced, and genome comparative analysis between these two species was carried out, together with the photosynthetic ability. The length is 141,187 bp for S. officinarum and that is 7 bp longer than S. spontaneum, with the same GC content (38.44%) and annotated gene number (134), 13 with introns among them. There is a typical tetrad structure, including LSC, SSC, IRb and IRa. Of them, LSC and IRa/IRb are 18 bp longer and 6 bp shorter than those in S. spontaneum (83,047 bp and 22,795 bp), respectively, while the size of SSC is same (12,544 bp). Five genes exhibit contraction and expansion at the IR junctions, but only one gene ndhF with 29 bp expansion at the border of IRb/SSC. Nucleotide diversity (Pi) based on sliding window analysis showed that the single copy and noncoding regions were more divergent than IR- and coding regions, and the variant hotspots trnG-trnM, psbM-petN, trnR-rps14, ndhC-trnV and petA-psbJ in the LSC and trnL-ccsA in the SSC regions were detected, and petA-psbJ with the highest divergent value of 0.01500. Genetic distances of 65 protein genes vary from 0.00000 to 0.00288 between two species, and the selective pressure on them indicated that only petB was subjected to positive selection, while more genes including rpoC2, rps3, ccsA, ndhA, ndhA, psbI, atpH and psaC were subjected to purifying or very strong purifying selection. There are larger number of codons in S. spontaneum than that in S. officinarum, while both species have obvious codon preference and the codons with highest-(AUG) and lowest frequency (AUA) are same. Whilst, the most abundant amino acid is leucine in both S. officinarum and S. spontaneum, with number of 2175 (10.88% of total) and 2228 (10.90% of total) codons, respectively, and the lowest number is cysteine, with only 221 (1.105%) and 224 (1.096%), respectively. Protein collinearity analysis showed the high collinearity though several divergences were present in cp genomes, and identification of simple sequence repeats (SSRs) were included in this study. In addition, in order to compare cold tolerance and explore the expanding function of this environmental stress, the chlorophyll relative content (SPAD) and chlorophyll fluorescence Fv/Fm were measured. The significantly higher SPAD were observed in S. spontaneum than those in S. officinarum, no matter what the control conditions, exposure to low temperature or during recovery, and so was for Fv/Fm under exposure to low temperature, together with higher level of SPAD in S. spontaneum in each measurement. Aforementioned results suggest much stronger photosynthetic ability and cold tolerance in S. spontaneum. Our findings build a foundation to investigate the biological mechanism of two sugarcane ancestor chloroplasts and retrieve reliable molecular resources for phylogenetic and evolutionary studies, and will be conducive to genetic improvement of photosynthetic ability and cold resistance in modern sugarcane.


Subject(s)
Cold-Shock Response , Genome, Chloroplast , Genomics , Photosynthesis , Saccharum/genetics , Saccharum/metabolism , Base Composition , Chlorophyll/metabolism , Chromosome Mapping , Codon , Cold-Shock Response/genetics , Genomics/methods , Open Reading Frames , Polymorphism, Single Nucleotide , Whole Genome Sequencing
14.
Australas Psychiatry ; 27(4): 345-347, 2019 Aug.
Article in English | MEDLINE | ID: mdl-30860396

ABSTRACT

OBJECTIVE: This article describes the voice hearing experiences of a young Maori man, and the joint Maori healing and psychiatry assessment he received, in which the Maori healer (WN) concluded that some of the young man's experiences could be accounted for by ancestral kaitiaki (spiritual guardians). CONCLUSIONS: Kaitiaki are commonly accepted in Te Ao Maori (the Maori world) as an explanation for some types of voice hearing experiences. Collaboration between a Maori healer and a psychiatrist can offer Maori whanau (individuals and families) more appropriate mental health assessment and intervention than conventional psychiatric assessment alone when Maori spiritual experiences are suspected.


Subject(s)
Culturally Competent Care , Culture , Hallucinations/therapy , Medicine, Traditional/psychology , Patient Acceptance of Health Care/psychology , Adolescent , Hallucinations/ethnology , Humans , Male , Native Hawaiian or Other Pacific Islander , New Zealand , Spiritual Therapies/psychology
15.
Proc Biol Sci ; 285(1893): 20181632, 2018 12 19.
Article in English | MEDLINE | ID: mdl-30963896

ABSTRACT

Phylogenies of mammals based on morphological data continue to show several major areas of conflict with the current consensus view of their relationships, which is based largely on molecular data. This raises doubts as to whether current morphological character sets are able to accurately resolve mammal relationships. We tested this under a hypothetical 'best case scenario' by using ancestral state reconstruction (under both maximum parsimony and maximum likelihood) to infer the morphologies of fossil ancestors for all clades present in a recent comprehensive DNA sequence-based phylogeny of mammals, and then seeing what effect the subsequent inclusion of these predicted ancestors had on unconstrained phylogenetic analyses of morphological data. We found that this resulted in topologies that are highly congruent with the current consensus phylogeny, at least when the predicted ancestors are assumed to be well preserved and densely sampled. Most strikingly, several analyses recovered the monophyly of clades that have never been found in previous morphology-only studies, such as Afrotheria and Laurasiatheria. Our results suggest that, at least in principle, improvements in the fossil record-specifically the discovery of fossil taxa that preserve the ancestral or near-ancestral morphologies of the nodes in the current consensus-may be sufficient to largely reconcile morphological and molecular estimates of mammal phylogeny, even using current morphological character sets.


Subject(s)
Base Sequence , Fossils , Mammals/classification , Phylogeny , Animals , Fossils/anatomy & histology , Mammals/anatomy & histology , Mammals/genetics
16.
BMC Genomics ; 18(1): 12, 2017 01 03.
Article in English | MEDLINE | ID: mdl-28049436

ABSTRACT

BACKGROUND: Fungal "Versatile carboxylic ester hydrolases" are enzymes with great biotechnological interest. Here we carried out a bioinformatic screening to find these proteins in genomes from Agaricales, by means of searching for conserved motifs, sequence and phylogenetic analysis, and three-dimensional modeling. Moreover, we reconstructed the molecular evolution of these enzymes along the time by inferring and analyzing the sequence of ancestral intermediate forms. RESULTS: The properties of the ancestral candidates are discussed on the basis of their three-dimensional structural models, the hydrophobicity of the lid, and the substrate binding intramolecular tunnel, revealing all of them featured properties of these enzymes. The evolutionary history of the putative lipases revealed an increase on the length and hydrophobicity of the lid region, as well as in the size of the substrate binding pocket, during evolution time. These facts suggest the enzymes' specialization towards certain substrates and their subsequent loss of promiscuity. CONCLUSIONS: These results bring to light the presence of different pools of lipases in fungi with different habitats and life styles. Despite the consistency of the data gathered from reconstruction of ancestral sequences, the heterologous expression of some of these candidates would be essential to corroborate enzymes' activities.


Subject(s)
Agaricales/genetics , Evolution, Molecular , Lipase/genetics , Agaricales/enzymology , Carboxylic Ester Hydrolases/chemistry , Carboxylic Ester Hydrolases/genetics , Genome, Fungal , Genomics/methods , Lipase/chemistry , Models, Molecular , Phylogeny , Protein Conformation
17.
Ann Hum Biol ; 44(4): 357-365, 2017 Jun.
Article in English | MEDLINE | ID: mdl-28325067

ABSTRACT

BACKGROUND: Genealogical analysis helps to better understand the genetic structure of populations. The population of Quebec (Canada) often serves as a model for this type of analysis, having one of the world's most complete genealogical databases. AIM: The main objective of this study was to reconstruct, analyse and compare the ascending genealogies of participants to CARTaGENE, a project that aims at building a database on various aspects of public health. SUBJECTS AND METHODS: In total, 5110 genealogies from four Quebec regions were reconstructed. Distribution of ancestors, completeness and depth of the genealogies, characteristics of immigrant ancestors and kinship and inbreeding coefficients were analysed. RESULTS: Most genealogies go back to the 17th century, with a mean genealogical depth of 10 generations. Origins of immigrant ancestors are more diverse in the Montreal region, resulting in lower inbreeding and kinship among the participants from this region. Inbreeding and kinship values are mainly explained by remote genealogical links (from 6 to 11 generations). CONCLUSION: Deep genealogies allowed for a precise measurement of the geographic origins of the participants' immigrant ancestors, as well as inbreeding and kinship ties in the population, which may be crucial for studies aiming to identify genetic variations associated with Mendelian or complex diseases.


Subject(s)
Genetic Variation , Pedigree , Adult , Aged , Emigrants and Immigrants , Female , Humans , Inbreeding , Male , Middle Aged , Quebec
18.
Health Care Anal ; 24(4): 301-320, 2016 Dec.
Article in English | MEDLINE | ID: mdl-24891191

ABSTRACT

The question of whether individuals retain interests or can be harmed after death is highly contentious, particularly within the context of deceased organ retrieval, retention and use. This paper argues that posthumous interests and/or harms can and do exist in the Konkomba (and wider Ghanaian) traditional setting through the concept of ancestorship, a reputational concept of immense cultural and existential significance in this setting. I adopt Joel Feinberg's account of harms as a setback to interests. The paper argues that a socio-culturally sensitive regulatory framework does not necessarily exclude the donation of (deceased) human biomaterials for transplant and science research. Indeed, when customary values are explored with open-mindedness and sensitivity it may be shown that such donation can form part of the important customs of some communities in this jurisdiction. Accordingly, a context-appropriate governance framework could utilise the cultural value of ancestorship as an incentive to encourage organ donation in the Ghanaian traditional setting.


Subject(s)
Culture , Death , Family/psychology , Informed Consent/standards , Tissue and Organ Procurement/standards , Biomedical Research , Ghana , Government Regulation , Humans , Tissue and Organ Procurement/methods
19.
Ecol Lett ; 18(9): 907-15, 2015 Sep.
Article in English | MEDLINE | ID: mdl-26100381

ABSTRACT

Agricultural practices such as breeding resistant varieties and pesticide use can cause rapid evolution of pest species, but it remains unknown how plant domestication itself impacts pest contemporary evolution. Using experimental evolution on a comparative phylogenetic scale, we compared the evolutionary dynamics of a globally important economic pest - the green peach aphid (Myzus persicae) - growing on 34 plant taxa, represented by 17 crop species and their wild relatives. Domestication slowed aphid evolution by 13.5%, maintained 10.4% greater aphid genotypic diversity and 5.6% higher genotypic richness. The direction of evolution (i.e. which genotypes increased in frequency) differed among independent domestication events but was correlated with specific plant traits. Individual-based simulation models suggested that domestication affects aphid evolution directly by reducing the strength of selection and indirectly by increasing aphid density and thus weakening genetic drift. Our results suggest that phenotypic changes during domestication can alter pest evolutionary dynamics.


Subject(s)
Aphids/genetics , Biological Evolution , Crops, Agricultural , Agriculture/methods , Animals , Breeding , Computer Simulation , Genetic Drift , Genetic Variation , Genotype , Herbivory , Models, Genetic , Phylogeny , Population Density , Population Dynamics , Selection, Genetic
20.
Mol Phylogenet Evol ; 83: 7-19, 2015 Feb.
Article in English | MEDLINE | ID: mdl-25463017

ABSTRACT

Earthworms belonging to the family Lumbricidae are extremely abundant in terrestrial temperate regions. They affect soil properties and nutrient cycling, thus shaping plant community composition and aboveground food webs. Some lumbricids are also model organisms in ecology and toxicology. Despite the intense research efforts dedicated to lumbricids over the last 130years, the evolutionary relationships and taxonomic classification of these organisms are still subject to great debate. Resolution of their systematics is hampered by the structural simplicity of the earthworm body plan and the existence of cryptic species. We sampled 160 earthworm specimens belonging to 84 lumbricid species (28 genera) and 22 Lumbricoidea outgroups, sequenced two nuclear genes, four mitochondrial genes and seven mitochondrial tRNAs and examined 22 morphological characters. We then applied a combination of phylogenetic methods to generate the first robust genus-level phylogeny of the Lumbricidae. Our results show that the current Lumbricidae classification and the underlying hypotheses of character evolution must be revised. Our chronogram suggests that lumbricids emerged in the Lower Cretaceous in the holarctic region and that their diversification has been driven by tectonic processes (e.g. Laurasia split) and geographical isolation. Our chronogram and character reconstruction analysis reveal that spermathecae number does not follow a gradual pattern of reduction and that parthenogenesis arose from sexual relatives multiple times in the group; the same analysis also indicates that both epigeic and anecic earthworms evolved from endogeic ancestors. These findings emphasize the strong and multiple changes to which morphological and ecological characters are subjected, challenging the hypothesis of character stasis in Lumbricidae.


Subject(s)
Biological Evolution , Oligochaeta/classification , Phylogeny , Animals , Bayes Theorem , Genes, Mitochondrial , Likelihood Functions , Models, Genetic , Oligochaeta/anatomy & histology , RNA, Transfer/genetics , Sequence Analysis, DNA
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