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Noskova E, Abramov N, Iliutkin S, Sidorin A, Dobrynin P, Ulyantsev VI. GADMA2: more efficient and flexible demographic inference from genetic data. Gigascience 2022; 12:giad059. [PMID: 37609916 PMCID: PMC10445054 DOI: 10.1093/gigascience/giad059] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 01/31/2023] [Accepted: 07/05/2023] [Indexed: 08/24/2023] Open
Abstract
BACKGROUND Inference of complex demographic histories is a source of information about events that happened in the past of studied populations. Existing methods for demographic inference typically require input from the researcher in the form of a parameterized model. With an increased variety of methods and tools, each with its own interface, the model specification becomes tedious and error-prone. Moreover, optimization algorithms used to find model parameters sometimes turn out to be inefficient, for instance, by being not properly tuned or highly dependent on a user-provided initialization. The open-source software GADMA addresses these problems, providing automatic demographic inference. It proposes a common interface for several likelihood engines and provides global parameters optimization based on a genetic algorithm. RESULTS Here, we introduce the new GADMA2 software and provide a detailed description of the added and expanded features. It has a renovated core code base, new likelihood engines, an updated optimization algorithm, and a flexible setup for automatic model construction. We provide a full overview of GADMA2 enhancements, compare the performance of supported likelihood engines on simulated data, and demonstrate an example of GADMA2 usage on 2 empirical datasets. CONCLUSIONS We demonstrate the better performance of a genetic algorithm in GADMA2 by comparing it to the initial version and other existing optimization approaches. Our experiments on simulated data indicate that GADMA2's likelihood engines are able to provide accurate estimations of demographic parameters even for misspecified models. We improve model parameters for 2 empirical datasets of inbred species.
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Affiliation(s)
- Ekaterina Noskova
- Computer Technologies Laboratory, ITMO University, St. Petersburg 197101, Russia
| | | | - Stanislav Iliutkin
- Computer Technologies Laboratory, ITMO University, St. Petersburg 197101, Russia
| | - Anton Sidorin
- Laboratory of Biochemical Genetics, St. Petersburg State University, St. Petersburg 199034, Russia
| | - Pavel Dobrynin
- Computer Technologies Laboratory, ITMO University, St. Petersburg 197101, Russia
- Human Genetics Laboratory, Vavilov Institute of General Genetics RAS, Moscow 119991, Russia
| | - Vladimir I Ulyantsev
- Computer Technologies Laboratory, ITMO University, St. Petersburg 197101, Russia
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Ochoa A, Onorato DP, Roelke-Parker ME, Culver M, Fitak RR. Give and Take: Effects of Genetic Admixture on Mutation Load in Endangered Florida Panthers. J Hered 2022; 113:491-499. [PMID: 35930593 DOI: 10.1093/jhered/esac037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Accepted: 08/02/2022] [Indexed: 11/14/2022] Open
Abstract
Genetic admixture is a biological event inherent to genetic rescue programs aimed at the long-term conservation of endangered wildlife. Although the success of such programs can be measured by the increase in genetic diversity and fitness of subsequent admixed individuals, predictions supporting admixture costs to fitness due to the introduction of novel deleterious alleles are necessary. Here, we analyzed nonsynonymous variation from conserved genes to quantify and compare levels of mutation load (i.e., proportion of deleterious alleles and genotypes carrying these alleles) among endangered Florida panthers and non-endangered Texas pumas. Specifically, we used canonical (i.e., non-admixed) Florida panthers, Texas pumas, and F1 (canonical Florida x Texas) panthers dating from a genetic rescue program and Everglades National Park panthers with Central American ancestry resulting from an earlier admixture event. We found neither genetic drift nor selection significantly reduced overall proportions of deleterious alleles in the severely bottlenecked canonical Florida panthers. Nevertheless, the deleterious alleles identified were distributed into a disproportionately high number of homozygous genotypes due to close inbreeding in this group. Conversely, admixed Florida panthers (either with Texas or Central American ancestry) presented reduced levels of homozygous genotypes carrying deleterious alleles but increased levels of heterozygous genotypes carrying these variants relative to canonical Florida panthers. Although admixture is likely to alleviate the load of standing deleterious variation present in homozygous genotypes, our results suggest introduced novel deleterious alleles (temporarily present in heterozygous state) in genetically rescued populations could potentially be expressed in subsequent generations if their effective sizes remain small.
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Affiliation(s)
- Alexander Ochoa
- Department of Biology and Genomics and Bioinformatics Cluster, University of Central Florida, Orlando, FL
| | - David P Onorato
- Fish and Wildlife Research Institute, Florida Fish and Wildlife Conservation Commission, Naples, FL
| | - Melody E Roelke-Parker
- Frederick National Laboratory of Cancer Research, Leidos Biomedical Research, Inc., Bethesda, MD
| | - Melanie Culver
- U.S. Geological Survey, Arizona Cooperative Fish and Wildlife Research Unit, and School of Natural Resources and the Environment, University of Arizona, Tucson, AZ
| | - Robert R Fitak
- Department of Biology and Genomics and Bioinformatics Cluster, University of Central Florida, Orlando, FL
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Tamazian G, Dobrynin P, Zhuk A, Zhernakova DV, Perelman PL, Serdyukova NA, Graphodatsky AS, Komissarov A, Kliver S, Cherkasov N, Scott AF, Mohr DW, Koepfli KP, O'Brien SJ, Krasheninnikova K. Draft de novo Genome Assembly of the Elusive Jaguarundi, Puma yagouaroundi. J Hered 2021; 112:540-548. [PMID: 34146095 PMCID: PMC8558579 DOI: 10.1093/jhered/esab036] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 06/17/2021] [Indexed: 11/12/2022] Open
Abstract
The Puma lineage within the family Felidae consists of 3 species that last shared a common ancestor around 4.9 million years ago. Whole-genome sequences of 2 species from the lineage were previously reported: the cheetah (Acinonyx jubatus) and the mountain lion (Puma concolor). The present report describes a whole-genome assembly of the remaining species, the jaguarundi (Puma yagouaroundi). We sequenced the genome of a male jaguarundi with 10X Genomics linked reads and assembled the whole-genome sequence. The assembled genome contains a series of scaffolds that reach the length of chromosome arms and is similar in scaffold contiguity to the genome assemblies of cheetah and puma, with a contig N50 = 100.2 kbp and a scaffold N50 = 49.27 Mbp. We assessed the assembled sequence of the jaguarundi genome using BUSCO, aligned reads of the sequenced individual and another published female jaguarundi to the assembled genome, annotated protein-coding genes, repeats, genomic variants and their effects with respect to the protein-coding genes, and analyzed differences of the 2 jaguarundis from the reference mitochondrial genome. The jaguarundi genome assembly and its annotation were compared in quality, variants, and features to the previously reported genome assemblies of puma and cheetah. Computational analyzes used in the study were implemented in transparent and reproducible way to allow their further reuse and modification.
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Affiliation(s)
- Gaik Tamazian
- Faculty of Biology, Saint Petersburg State University, St. Petersburg, Russia
| | - Pavel Dobrynin
- Computer Technologies Laboratory, ITMO University, St. Petersburg, Russia
| | - Anna Zhuk
- Computer Technologies Laboratory, ITMO University, St. Petersburg, Russia
| | - Daria V Zhernakova
- Computer Technologies Laboratory, ITMO University, St. Petersburg, Russia.,Department of Genetics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | | | | | | | - Aleksey Komissarov
- Applied Genomics Laboratory, SCAMT Institute, ITMO University, St. Petersburg, Russia
| | - Sergei Kliver
- Institute of Molecular and Cellular Biology, Novosibirsk, Russia
| | - Nikolay Cherkasov
- Faculty of Biology, Saint Petersburg State University, St. Petersburg, Russia.,Centre for Computational Biology, Peter the Great Saint Petersburg Polytechnic University, St. Petersburg, Russia
| | - Alan F Scott
- Genetic Resources Core Facility, McKusick-Nathans Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - David W Mohr
- Genetic Resources Core Facility, McKusick-Nathans Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Klaus-Peter Koepfli
- Smithsonian-Mason School of Conservation, Front Royal, VA, USA.,Center for Species Survival, Smithsonian Conservation Biology Institute, National Zoological Park, Washington, DC, USA
| | - Stephen J O'Brien
- Computer Technologies Laboratory, ITMO University, St. Petersburg, Russia.,Guy Harvey Oceanographic Center, Nova Southeastern University, Fort Lauderdale, FL, USA
| | - Ksenia Krasheninnikova
- Computer Technologies Laboratory, ITMO University, St. Petersburg, Russia.,Wellcome Trust Sanger Institute, Cambridge, UK
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Blischak PD, Barker MS, Gutenkunst RN. Inferring the Demographic History of Inbred Species from Genome-Wide SNP Frequency Data. Mol Biol Evol 2021; 37:2124-2136. [PMID: 32068861 DOI: 10.1093/molbev/msaa042] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 02/04/2020] [Accepted: 02/13/2020] [Indexed: 01/04/2023] Open
Abstract
Demographic inference using the site frequency spectrum (SFS) is a common way to understand historical events affecting genetic variation. However, most methods for estimating demography from the SFS assume random mating within populations, precluding these types of analyses in inbred populations. To address this issue, we developed a model for the expected SFS that includes inbreeding by parameterizing individual genotypes using beta-binomial distributions. We then take the convolution of these genotype probabilities to calculate the expected frequency of biallelic variants in the population. Using simulations, we evaluated the model's ability to coestimate demography and inbreeding using one- and two-population models across a range of inbreeding levels. We also applied our method to two empirical examples, American pumas (Puma concolor) and domesticated cabbage (Brassica oleracea var. capitata), inferring models both with and without inbreeding to compare parameter estimates and model fit. Our simulations showed that we are able to accurately coestimate demographic parameters and inbreeding even for highly inbred populations (F = 0.9). In contrast, failing to include inbreeding generally resulted in inaccurate parameter estimates in simulated data and led to poor model fit in our empirical analyses. These results show that inbreeding can have a strong effect on demographic inference, a pattern that was especially noticeable for parameters involving changes in population size. Given the importance of these estimates for informing practices in conservation, agriculture, and elsewhere, our method provides an important advancement for accurately estimating the demographic histories of these species.
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Affiliation(s)
- Paul D Blischak
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ.,Department of Molecular and Cellular Biology, University of Arizona, Tucson, AZ
| | - Michael S Barker
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ
| | - Ryan N Gutenkunst
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, AZ
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Padial JM, De la Riva I. A paradigm shift in our view of species drives current trends in biological classification. Biol Rev Camb Philos Soc 2020; 96:731-751. [PMID: 33368983 DOI: 10.1111/brv.12676] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 11/21/2020] [Accepted: 11/25/2020] [Indexed: 12/22/2022]
Abstract
Discontent about changes in species classifications has grown in recent years. Many of these changes are seen as arbitrary, stemming from unjustified conceptual and methodological grounds, or leading to species that are less distinct than those recognised in the past. We argue that current trends in species classification are the result of a paradigm shift toward which systematics and population genetics have converged and that regards species as the phylogenetic lineages that form the branches of the Tree of Life. Species delimitation now consists of determining which populations belong to which individual phylogenetic lineage. This requires inferences on the process of lineage splitting and divergence, a process to which we have only partial access through incidental evidence and assumptions that are themselves subject to refutation. This approach is not free of problems, as horizontal gene transfer, introgression, hybridisation, incorrect assumptions, sampling and methodological biases can mislead inferences of phylogenetic lineages. Increasing precision is demanded through the identification of both sister relationships and processes blurring or mimicking phylogeny, which has triggered, on the one hand, the development of methods that explicitly address such processes and, on the other hand, an increase in geographical and character data sampling necessary to infer/test such processes. Although our resolving power has increased, our knowledge of sister relationships - what we designate as species resolution - remains poor for many taxa and areas, which biases species limits and perceptions about how divergent species are or ought to be. We attribute to this conceptual shift the demise of trinominal nomenclature we are witnessing with the rise of subspecies to species or their rejection altogether; subspecies are raised to species if they are found to correspond to phylogenetic lineages, while they are rejected as fabricated taxa if they reflect arbitrary partitions of continuous or non-hereditary variation. Conservation strategies, if based on taxa, should emphasise species and reduce the use of subspecies to avoid preserving arbitrary partitions of continuous variation; local variation is best preserved by focusing on biological processes generating ecosystem resilience and diversity rather than by formally naming diagnosable units of any kind. Since many binomials still designate complexes of species rather than individual species, many species have been discovered but not named, geographical sampling is sparse, gene lineages have been mistaken for species, plenty of species limits remain untested, and many groups and areas lack adequate species resolution, we cannot avoid frequent changes to classifications as we address these problems. Changes will not only affect neglected taxa or areas, but also popular ones and regions where taxonomic research remained dormant for decades and old classifications were taken for granted.
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Affiliation(s)
- José M Padial
- Department of Herpetology, American Museum of Natural History, Central Park West & 79th St., New York, NY, 10024, U.S.A.,Department of Biology, Bronx Community College, City University of New York, 2155 University Avenue, Bronx, NY, 10453, U.S.A
| | - Ignacio De la Riva
- Museo Nacional de Ciencias Naturales-CSIC, José Gutiérrez Abascal 2, Madrid, 28006, Spain
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