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Bogart JP. Gynogenetic diploids, tetraploids, or octoploids, and a path to polyploidy in Anuran Amphibians. Genome 2021; 64:1053-1065. [PMID: 34129779 DOI: 10.1139/gen-2021-0019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Unreduced gametes have been implicated in the evolution of polyploid species of plants and animals and are normally produced by female anuran amphibians. Such eggs may initiate the evolution of polyploid species that have independently arisen in several anuran families. Polyploid females could also produce unreduced eggs that might lead to species with higher ploidy levels or their eggs may develop gynogenetically to reduce the ploidy level. Diploid Hyla chrysoscelis (2n=24) and tetraploid H. versicolor (4n=48) are sibling cryptic species of North American Grey Treefrogs. Artificial crosses using H. versicolor females and genetically distant diploid males were performed to produce haploid H. versicolor and to assess the production of unreduced eggs in this tetraploid species. Gynogenetic diploid (haploid H. versicolor), allotriploid, gynogenetic tetraploid, allopentaploid, autohexaploid, and gynogenetic octoploid tadpoles were confirmed using chromosome counts from tadpole tail tip squashes. Transformation and survival of the different ploidies varied. Gynogenetic diploids transformed but expressed aspects of the haploid syndrome and died before or shortly after transformation.
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Affiliation(s)
- James P Bogart
- University of Guelph, Department of Integrative Biology, University of Guelph, Guelph, Ontario, Canada, N1G 2W1;
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Grenat P, Salas N, Pollo F, Otero M, Baraquet M, Sinsch U, Martino A. Naturally occurring triploids in contact zones between diploid/tetraploid Odontophrynus cordobae and O. americanus (Anura, Odontophrynidae). AMPHIBIA-REPTILIA 2018. [DOI: 10.1163/15685381-00003141] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Polyploidization plays an important role in speciation and evolution in anurans. However, a few stable triploid populations and some isolated triploid individuals have been reported. Here, we report the discovery of naturally occurring triploids in contact zones between diploidOdontophrynus cordobaeand tetraploidO. americanusfrom Central Argentina, and propose values of erythrocyte area for the distinction of ploidy levels. A total of 101 individuals from three contact zones were studied and ploidy of each specimen was identified by mean chromosome count and erythrocyte size. Twenty three adult triploid specimens (males: ; females: ) from two contact sites were identified (percentage of individuals per ploidy level: site S2, %, %, %; site S3: %, %, %). The limit values of erythrocyte nuclear area used to distinguish between different ploidy levels were 23.62 μm2(probability to be assigned to a respective ploidy level = 94.78%) for separating diploids and triploids and 27.67 μm2(98.62%) for triploids and tetraploids. The high number of adult triploids occurring in more than one contact site betweenO. cordobaeandO. americanusindicates that is not an isolated event. However, further studies are necessary to provide a hypothesis on the origin and evaluate the possible maintenance of triploids in syntopy withO. cordobaeandO. americanus.
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Affiliation(s)
- Pablo Grenat
- Ecología, Departamento de Ciencias Naturales, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Ruta Nacional N° 36 – km 601, (X5804BYA) Río Cuarto, Argentina
- CONICET
| | - Nancy Salas
- Ecología, Departamento de Ciencias Naturales, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Ruta Nacional N° 36 – km 601, (X5804BYA) Río Cuarto, Argentina
| | - Favio Pollo
- Ecología, Departamento de Ciencias Naturales, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Ruta Nacional N° 36 – km 601, (X5804BYA) Río Cuarto, Argentina
- CONICET
| | - Manuel Otero
- Ecología, Departamento de Ciencias Naturales, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Ruta Nacional N° 36 – km 601, (X5804BYA) Río Cuarto, Argentina
- CONICET
| | - Mariana Baraquet
- Ecología, Departamento de Ciencias Naturales, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Ruta Nacional N° 36 – km 601, (X5804BYA) Río Cuarto, Argentina
- CONICET
| | - Ulrich Sinsch
- Department of Biology, Zoology Group, University of Koblenz-Landau, Koblenz, Germany
| | - Adolfo Martino
- Ecología, Departamento de Ciencias Naturales, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Ruta Nacional N° 36 – km 601, (X5804BYA) Río Cuarto, Argentina
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