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Wighard SS, Athanasouli M, Witte H, Rödelsperger C, Sommer RJ. A New Hope: A Hermaphroditic Nematode Enables Analysis of a Recent Whole Genome Duplication Event. Genome Biol Evol 2022; 14:6868937. [PMID: 36461901 PMCID: PMC9763058 DOI: 10.1093/gbe/evac169] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 11/03/2022] [Accepted: 11/22/2022] [Indexed: 12/05/2022] Open
Abstract
Whole genome duplication (WGD) is often considered a major driver of evolution that leads to phenotypic novelties. However, the importance of WGD for evolution is still controversial because most documented WGD events occurred anciently and few experimental systems amenable to genetic analysis are available. Here, we report a recent WGD event in the hermaphroditic nematode Allodiplogaster sudhausi and present a comparison with a gonochoristic (male/female) sister species that did not undergo WGD. Self-fertilizing reproduction of A. sudhausi makes it amenable to functional analysis and an ideal system to study WGD events. We document WGD in A. sudhausi through karyotype analysis and whole genome sequencing, the latter of which allowed us to 1) identify functional bias in retention of protein domains and metabolic pathways, 2) show most duplicate genes are under evolutionary constraint, 3) show a link between sequence and expression divergence, and 4) characterize differentially expressed duplicates. We additionally show WGD is associated with increased body size and an abundance of repeat elements (36% of the genome), including a recent expansion of the DNA-hAT/Ac transposon family. Finally, we demonstrate the use of CRISPR/Cas9 to generate mutant knockouts, whereby two WGD-derived duplicate genes display functional redundancy in that they both need to be knocked out to generate a phenotype. Together, we present a novel experimental system that is convenient for examining and characterizing WGD-derived genes both computationally and functionally.
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Affiliation(s)
- Sara S Wighard
- Department for Integrative Evolutionary Biology, Max Planck Institute for Biology Tübingen, Max Planck Ring 9, 72076 Tübingen, Germany
| | - Marina Athanasouli
- Department for Integrative Evolutionary Biology, Max Planck Institute for Biology Tübingen, Max Planck Ring 9, 72076 Tübingen, Germany
| | - Hanh Witte
- Department for Integrative Evolutionary Biology, Max Planck Institute for Biology Tübingen, Max Planck Ring 9, 72076 Tübingen, Germany
| | - Christian Rödelsperger
- Department for Integrative Evolutionary Biology, Max Planck Institute for Biology Tübingen, Max Planck Ring 9, 72076 Tübingen, Germany
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Mahboob M, Chavan SN, Nazir N, Mustaqim M, Jahan R, Tahseen Q. Description of a new and two known species of the insect–associated genus Oigolaimella Paramonov, 1952 (Nematoda: Diplogastridae) with a note on the biology, biogeography and relationship with congeners. ZOOL ANZ 2021. [DOI: 10.1016/j.jcz.2021.09.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Kanzaki N, Hamaguchi K. Pristionchus trametes n. sp. (Diplogastridae) isolated from the mushroom Trametes orientalis in Kyoto, Japan. J Nematol 2021; 53:e2021-60. [PMID: 34296192 PMCID: PMC8290503 DOI: 10.21307/jofnem-2021-060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Indexed: 12/02/2022] Open
Abstract
A new species of Pristionchus was isolated from fruiting bodies of the wood-decaying fungus Trametes orientalis collected from Kyoto, Japan. Attempts to culture it using bacteria, yeast, and freeze-killed wax moth larvae as food or substrate failed. The eurystomatous form of the species was not found in the collected material, and the species is typologically characterized by: its ‘small’ stoma with thin, membrane-like cheilostomatal plates, a small triangular right subventral tooth, thorn-like dorsal tooth, and small left subventral denticles; a short, blunt male tail spike; and a short, conical female tail. Although the posterior probability support was not high (66%), phylogenetic analysis of both small and large ribosomal RNA gene subunits suggests that the species is closely related to P. elegans and P. bucculentus. The new species can be distinguished from those two by its diagnostic characters comprising the stomatal morphology and male and female tail characters.
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Affiliation(s)
- Natsumi Kanzaki
- Kanzsai Research Center, Forestry and Forest Products Research Institute, 68 Nagaikyutaroh, Momoyama, Fushimi, Kyoto, 612-0855, Japan
| | - Keiko Hamaguchi
- Kanzsai Research Center, Forestry and Forest Products Research Institute, 68 Nagaikyutaroh, Momoyama, Fushimi, Kyoto, 612-0855, Japan
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Bartlow AW, Agosta SJ. Phoresy in animals: review and synthesis of a common but understudied mode of dispersal. Biol Rev Camb Philos Soc 2020; 96:223-246. [PMID: 32924275 DOI: 10.1111/brv.12654] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 08/27/2020] [Accepted: 08/28/2020] [Indexed: 12/30/2022]
Abstract
Phoresy is a type of interaction in which one species, the phoront, uses another species, the dispersal host, for transportation to new habitats or resources. Despite being a widespread behaviour, little is known about the ecology and evolution of phoresy. Our goal is to provide a comprehensive review of phoretic dispersal in animals and to bring renewed attention to this subject. We surveyed literature published between 1900 and 2020 to understand the extent of known higher-level taxonomic diversity (phyla, classes, and orders) and functional aspects of animals that use phoretic dispersal. Species dispersing phoretically have been observed in at least 13 animal phyla, 25 classes, and 60 orders. The majority of known phoronts are arthropods (Phylum Euarthropoda) in terrestrial habitats, but phoronts also occur in freshwater and marine environments. Marine phoronts may be severely under-represented in the literature due to the relative difficulty of studying these systems. Phoronts are generally small with low mobility and use habitats or resources that are ephemeral and/or widely dispersed. Many phoronts are also parasites. In general, animals that engage in phoresy use a wide variety of morphological and behavioural traits for locating, attaching to, and detaching from dispersal hosts, but the exact mechanisms behind these activities are largely unknown. In addition to diversity, we discuss the evolution of phoresy including the long-standing idea that it can be a precursor to parasitism and other forms of symbioses. Finally, we suggest several areas of future research to improve our understanding of phoresy and its ecological and evolutionary significance.
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Affiliation(s)
- Andrew W Bartlow
- Biosecurity and Public Health, Los Alamos National Laboratory, Mailstop M888, Los Alamos, NM, 87545, U.S.A
| | - Salvatore J Agosta
- Center for Environmental Studies, VCU Life Sciences, Virginia Commonwealth University, 1000 W. Cary St., Richmond, VA, 23284, U.S.A
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Kanzaki N, Liang WR, Chiu CI, Li HF. Acrostichus ziaelasi n. sp. (Nematoda: Diplogastridae) isolated from the beetle Ziaelas formosanus, a tenebrionid symbiont of the termite Odontotermes formosanus with remarks on the genus Acrostichus Rahm, 1928. ZOOL ANZ 2020. [DOI: 10.1016/j.jcz.2020.03.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Feeding Dimorphism in a Mycophagous Nematode, Bursaphelenchus sinensis. Sci Rep 2019; 9:13956. [PMID: 31562356 PMCID: PMC6765002 DOI: 10.1038/s41598-019-50462-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Accepted: 09/09/2019] [Indexed: 02/03/2023] Open
Abstract
Phenotypic plasticity has been widely reported in animals and can drive investment in new biological characters that engender ecological adaptability. The nematode family Diplogastridae, especially Pristionchus pacificus with its dramatic stomatal (feeding) dimorphism, has become an important model system to analyze the evolutionary and developmental aspects of polyphenism. However, this plasticity has not been confirmed in other nematode groups. In the present study, we experimentally examined the feeding dimorphism of a fungal feeding free-living nematode, Bursaphelenchus sinensis. In a laboratory culturing experiment, the nematode expressed dimorphism, i.e., a small proportion of the population manifested as a predatory form. This form only occurred in females and was not clearly influenced by the presence of potential prey species. In addition, the ratio of the predatory form to the mycophagous form varied among different fungal food species grown in monoculture on different culture media. The predatory form of B. sinensis was typologically similar to the monomorphic (specialized) predators belonging to the same family. However, some essential morphological characters were slightly different from the specialized predators, and their behaviours were clearly disparate, suggesting that predation in B. sinensis is derived from a different phylogenetic origin than that of the specialized predators.
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Morphological and molecular characteristics of Parasitodiplogaster religiosae n. sp. (Nematoda: Diplogastrina) associated with Ficus religiosa in China. PLoS One 2018; 13:e0199417. [PMID: 29995895 PMCID: PMC6040748 DOI: 10.1371/journal.pone.0199417] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Accepted: 06/07/2018] [Indexed: 12/04/2022] Open
Abstract
A new nematode species of the genus Parasitodiplogaster was recovered from syconia of Ficus religiosa at the Guangxiao Temple, Guangzhou, China. It is described herein as P. religiosae n. sp. and is characterised by possessing the longest and thinnest spicule of all currently described males in the genus, an elongated laterally “ε-shaped” and ventrally rhomboid-like gubernaculum, a stoma without teeth, consisting of a ring-like cheilostom with indistinct anteriolateral projections, a tube-like gymnostom and a funnel-like stegostom, monodelphic with a mean vulval position of 66%. There are three pre-cloacal and six post-cloacal male genital papillae with the arrangement P1, P2, P3, (C, P4), P5, P6d, P7, P8, P9d, Ph. This new species was easily differentiated from other members of the genus by DNA sequences of partial small subunit rRNA gene (SSU) and the D2-D3 expansion segments of the large subunit rRNA gene (LSU). Phylogenetic analysis also corroborated its reasonable placement within a well-supported monophyletic clade with other Parasitodiplogaster species and within the australis-group that includes P. australis and P. salicifoliae that are all associates of fig wasp pollinators (Platyscapa sp.) of figs of the subsection Urostigma.
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Tanaka SE, Aikawa T, Takeuchi-Kaneko Y, Fukuda K, Kanzaki N. Artificial induction of third-stage dispersal juveniles of Bursaphelenchus xylophilus using newly established inbred lines. PLoS One 2017; 12:e0187127. [PMID: 29073232 PMCID: PMC5658132 DOI: 10.1371/journal.pone.0187127] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2017] [Accepted: 10/13/2017] [Indexed: 11/18/2022] Open
Abstract
The pine wood nematode, Bursaphelenchus xylophilus, is the causal agent of pine wilt disease. This nematode has two developmental forms in its life cycle; i.e., the propagative and dispersal forms. The former is the form that builds up its population inside the host pine. The latter is specialized for transport by the vector. This form is separated into two dispersal stages (third and fourth); the third-stage dispersal juvenile (JIII) is specialized for survival under unfavorable conditions, whereas the fourth-stage juvenile (JIV), which is induced by a chemical signal from the carrier Monochamus beetle, is transported to new host pines and invades them. Because of its importance in the disease cycle, molecular and chemical aspects of the JIV have been investigated, while the mechanism of JIII induction has not been sufficiently investigated. In an effort to clarify the JIII induction process, we established inbred lines of B. xylophilus and compared their biological features. We found that the total number of nematodes (propagation proportion) was negatively correlated with the JIII emergence proportion, likely because nematode development was arrested at JIII; i.e., they could not develop to adults via the reproductive stage. In addition, JIII induction seemed to be regulated by a small number of genes because the JIII induction proportion varied among inbred lines despite the high homozygosity of the parental line. We also demonstrated that JIII can be artificially induced by the nematode's secreted substances. This is the first report of artificial induction of JIII in B. xylophilus. The dauer (dispersal) juvenile of the model organism Caenorhabditis elegans corresponds functionally to JIII of B. xylophilus, and this stage is known to be induced by a chemical signal referred to as daumone, derived from the nematodes' secretion. The artificial induction of JIII suggests the presence of daumone-like material in B. xylophilus.
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Affiliation(s)
- Suguru E. Tanaka
- Laboratory of Forest Botany, Graduate School of Agricultural and Life Sciences, the University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Takuya Aikawa
- Tohoku Research Center, Forestry and Forest Products Research Institute (FFPRI), Morioka, Iwate, Japan
| | - Yuko Takeuchi-Kaneko
- Laboratory of Terrestrial Microbial Ecology, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto, Japan
| | - Kenji Fukuda
- Laboratory of Forest Botany, Graduate School of Agricultural and Life Sciences, the University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Natsumi Kanzaki
- Kansai Research Center, FFPRI, Fushimi, Kyoto, Japan
- * E-mail:
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Stomatal Dimorphism of Neodiplogaster acaloleptae (Diplogastromorpha: Diplogastridae). PLoS One 2016; 11:e0155715. [PMID: 27196730 PMCID: PMC4873264 DOI: 10.1371/journal.pone.0155715] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Accepted: 05/03/2016] [Indexed: 11/19/2022] Open
Abstract
Several genera belonging to the nematode family Diplogastridae show characteristic dimorphism in their feeding structures; specifically, they have microbial feeding stenostomatous and predatory eurystomatous morphs. A diplogastrid satellite model species, Pristionchus pacificus, and its close relatives have become a model system for studying this phenotypic plasticity, with intensive physiological and structural studies having been undertaken. However, the many other species that are morphologically and phylogenetically divergent from P. pacificus have not been examined to date. In the present study, the detailed stomatal structure and induction of dimorphism in Neodiplogaster acaloleptae were examined. N. acaloleptae has a fungal feeding stenostomatous morph and a predatory eurystomatous morph. The predatory morph was induced by starvation, high population density, and co-culturing with its potential prey, Caenorhabditis elegans. The feeding behavior of the stenostomatous and eurystomatous morphs of N. acaloleptae was confirmed, demonstrating that 1) the stomatal and pharyngeal movements of the two morphs were basically identical, and 2) the stomatal elements were protracted to cut open the hyphae and/or prey to feed when a N. acaloleptae flips its dorsal movable tooth dorsally and tilts its subventral stegostomatal cylinder ventrally, forming a pair of scissors to cut the food source. The stoma morphology of N. acaloleptae with a single movable tooth and a long stoma is markedly different from that of Pristionchus, which has two movable teeth and a short stoma. It is, however, similar to that of Mononchoides, tentatively a sister to Neodiplogaster.
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