INTRODUCTION: Reproductive isolation and hybrid sterility are mechanisms that maintain the genetic integrity of species and prevent the introgression of heterospecific genes. However, crosses of closely related species can lead to complex evolution, such as the formation of all-female lineages that reproduce clonally. Bighead catfish (Clarias macrocephalus) and North African catfish (C. gariepinus) diverged 40 million years ago. They are cultivated and hybridized in Thailand for human consumption. Male hybrids are sterile due to genome-wide chromosome asynapsis during meiosis. Although female hybrids are sometimes fertile, their chromosome configuration during meiosis has not yet been studied. METHODS: We analyzed meiosis in the hybrid female catfish at pachytene (synaptonemal complexes) and diplotene (lampbrush chromosomes), using immunostaining to detect chromosome pairing and double-stranded break formation, and FISH with species-specific satellite DNAs to distinguish the parental chromosomes. RESULTS: More than 95% of oocytes exhibited chromosome asynapsis in female hybrid catfish; however, they were able to progress to the diplotene stage and form mature eggs. The remaining oocytes underwent premeiotic endoreplication, followed by synapsis and crossing over between sister chromosomes, similar to known clonal lineages in fish and reptiles. DISCUSSION: The occurrence of clonal reproduction in female hybrid catfish suggests a unique model for studying gametogenic alterations caused by hybridization and their potential for asexual reproduction. Our results further support the view that clonal reproduction in certain hybrid animals relies on intrinsic mechanisms of sexually reproducing parental species, given their multiple independent origins with the same mechanism.

Animal Genomics and Bioresource Research Unit Faculty of Science Kasetsart University Bangkok Thailand

Biodiversity Center Kasetsart University Bangkok Thailand

Department of Biology and Ecology Faculty of Natural Sciences University of Ostrava Ostrava Czechia

Department of Gene Function and Phenomics National Institute of Genetics Mishima Japan

Institute of Cytology and Genetics Russian Academy of Sciences Siberian Branch Novosibirsk Russia

Laboratory of Non Mendelian Evolution Institute of Animal Physiology and Genetics Czech Academy of Sciences Liběchov Czechia

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Abbott R., Albach D., Ansell S., Arntzen J. W., Baird S. J., Bierne N., et al. (2013). Hybridization and speciation. J. Evol. Biol. 26 (2), 229–246. 10.1111/j.1420-9101.2012.02599.x PubMed DOI

Abol-Munafi A. B., Liem P. T., Ambak M. A., Siraj S. S. (2006). Effects of maturational hormone treatment on spermatogenesis of hybrid catfish (Clarias macrocephalus x C. gariepinus). J. Sustain. Sci. Manag. 1 (1), 24–31.

Anderson L. K., Reeves A., Webb L. M., Ashley T. (1999). Distribution of crossing over on mouse synaptonemal complexes using immunofluorescent localization of MLH1 protein. Genetics 151 (4), 1569–1579. 10.1093/genetics/151.4.1569 PubMed DOI PMC

Avise I. J. (2008). Clonality: the genetics, ecology, and evolution of sexual abstinence in vertebrate animals. New York: Oxford University Press.

Balogh R. E., Csorbai B., Guti C., Keszte S., Urbányi B., Orbán L., et al. (2023). Validation of a male-specific DNA marker confirms XX/XY-type sex determination in several Hungarian strains of African catfish (Clarias gariepinus). Theriogenology 205, 106–113. 10.1016/j.theriogenology.2023.04.017 PubMed DOI

Blokhina Y. P., Nguyen A. D., Draper B. W., Burgess S. M. (2019). The telomere bouquet is a hub where meiotic double-strand breaks, synapsis, and stable homolog juxtaposition are coordinated in the zebrafish, Danio rerio . PLoS Genet. 15 (1), e1007730. 10.1371/journal.pgen.1007730 PubMed DOI PMC

Caeiro‐Dias G., Brelsford A., Meneses‐Ribeiro M., Crochet P. A., Pinho C. (2023). Hybridization in late stages of speciation: strong but incomplete genome‐wide reproductive isolation and “large Z‐effect” in a moving hybrid zone. Mol. Ecol. 32 (15), 4362–4380. 10.1111/mec.17035 PubMed DOI

Castiglia R. (2014). Sympatric sister species in rodents are more chromosomally differentiated than allopatric ones: implications for the role of chromosomal rearrangements in speciation. Mammal. Rev. 44 (1), 1–4. 10.1111/mam.12009 DOI

Chalermwong P., Panthum T., Wattanadilokcahtkun P., Ariyaraphong N., Thong T., Srikampa P., et al. (2023). Overcoming taxonomic challenges in DNA barcoding for improvement of identification and preservation of clariid catfish species. Genomics Inf. 21 (3), e39. 10.5808/gi.23038 PubMed DOI PMC

Choleva L., Janko K., De Gelas K., Bohlen J., Šlechtová V., Rábová M., et al. (2012). Synthesis of clonality and polyploidy in vertebrate animals by hybridization between two sexual species. Evolution 66 (7), 2191–2203. 10.1111/j.1558-5646.2012.01589.x PubMed DOI

Cuellar O. (1971). Reproduction and the mechanism of meiotic restitution in the parthenogenetic lizard Cnemidophorus uniparens . J. Morphol. 133 (2), 139–165. 10.1002/jmor.1051330203 PubMed DOI

Dedukh D., Altmanová M., Klíma J., Kratochvíl L. (2022a). Premeiotic endoreplication is essential for obligate parthenogenesis in geckos. Development 149 (7), dev200345. 10.1242/dev.200345 PubMed DOI

Dedukh D., Da Cruz I., Kneitz S., Marta A., Ormanns J., Tichopád T., et al. (2022b). Achiasmatic meiosis in the unisexual Amazon molly, Poecilia formosa . Chromosome Res. 30 (4), 443–457. 10.1007/s10577-022-09708-2 PubMed DOI PMC

Dedukh D., Krasikova A. (2022). Delete and survive: strategies of programmed genetic material elimination in eukaryotes. Biol. Rev. 97 (1), 195–216. 10.1111/brv.12796 PubMed DOI PMC

Dedukh D., Litvinchuk S., Rosanov J., Mazepa G., Saifitdinova A., Shabanov D., et al. (2015). Optional endoreplication and selective elimination of parental genomes during oogenesis in diploid and triploid hybrid European water frogs. PLoS One 10 (4), e0123304. 10.1371/journal.pone.0123304 PubMed DOI PMC

Dedukh D., Majtánová Z., Marta A., Pšenička M., Kotusz J., Klíma J., et al. (2020). Parthenogenesis as a solution to hybrid sterility: the mechanistic basis of meiotic distortions in clonal and sterile hybrids. Genetics 215 (4), 975–987. 10.1534/genetics.119.302988 PubMed DOI PMC

Dedukh D., Marta A., Janko K. (2021). Challenges and costs of asexuality: variation in premeiotic genome duplication in gynogenetic hybrids from Cobitis taenia complex. Int. J. Mol. Sci. 22 (22), 12117. 10.3390/ijms222212117 PubMed DOI PMC

Dedukh D., Altmanová M., Petrosyan R., Arakelyan M., Galoyan E., Kratochvíl L., et al. (2024). Premeiotic endoreplication is the mechanism of obligate parthenogenesis in rock lizards of the genus Darevskia. bioRxiv. 10.1101/2024.02.27.582286 DOI

de Massy B. (2013). Initiation of meiotic recombination: how and where? Conservation and specificities among eukaryotes. Annu. Rev. Genet. 47 (1), 563–599. 10.1146/annurev-genet-110711-155423 PubMed DOI

Dufresnes C., Majtyka T., Baird S. J., Gerchen J. F., Borzée A., Savary R., et al. (2016). Empirical evidence for large X-effects in animals with undifferentiated sex chromosomes. Sci. Rep. 6 (1), 21029. 10.1038/srep21029 PubMed DOI PMC

Gall J. G., Murphy C., Callan H. G., Wu Z. (1991). Lampbrush chromosomes. Met. Cell Biol. 36, 149–166. PubMed

Hopkins R. (2013). Reinforcement in plants. New Phytol. 197 (4), 1095–1103. 10.1111/nph.12119 PubMed DOI

Imai Y., Olaya I., Sakai N., Burgess S. M. (2021). Meiotic chromosome dynamics in zebrafish. Front. Cell Dev. Biol. 9, 757445. 10.3389/fcell.2021.757445 PubMed DOI PMC

Itono M., Morishima K., Fujimoto T., Bando E., Yamaha E., Arai K. (2006). Premeiotic endomitosis produces diploid eggs in the natural clone loach, Misgurnus anguillicaudatus (Teleostei: cobitidae). J. Exp. Zool. A Comp. Exp. Biol. 305 (6), 513–523. 10.1002/jez.a.283 PubMed DOI

Janko K., Pačes J., Wilkinson‐Herbots H., Costa R. J., Roslein J., Drozd P., et al. (2018). Hybrid asexuality as a primary postzygotic barrier between nascent species: on the interconnection between asexuality, hybridization and speciation. Mol. Ecol. 27 (1), 248–263. 10.1111/mec.14377 PubMed DOI PMC

Kim I., Lee J. (1990). Diploid-triploid complex of the spined loach Cobitis sinensis and C. longicorpus (Pisces, Cobitidae). Korean J. Ichthyol. 2, 203–210.

Kitano J., Mori S., Peichel C. L. (2007). Sexual dimorphism in the external morphology of the threespine stickleback (Gasterosteus aculeatus). Copeia 2007 (2), 336–349. 10.1643/0045-8511(2007)7[336:SDITEM]2.0.CO;2 DOI

Kuroda M., Fujimoto T., Murakami M., Yamaha E., Arai K. (2018). Clonal reproduction assured by sister chromosome pairing in dojo loach, a teleost fish. Chromosome Res. 26 (4), 243–253. 10.1007/s10577-018-9581-4 PubMed DOI

Lampert K. P., Steinlein C., Schmid M., Fischer P., Schartl M. (2007). A haploid-diploid-triploid mosaic of the Amazon molly, Poecilia formosa . Cytogenet. Genome Res. 119 (1–2), 131–134. 10.1159/000109629 PubMed DOI

Lisachov A., Nguyen D. H., Panthum T., Ahmad S. F., Singchat W., Ponjarat J., et al. (2023). Emerging importance of bighead catfish (Clarias macrocephalus) and North African catfish (C. gariepinus) as a bioresource and their genomic perspective. Aquaculture 573, 739585. 10.1016/j.aquaculture.2023.739585 DOI

Lisachov A., Panthum T., Dedukh D., Singchat W., Ahmad S. F., Wattanadilokcahtkun P., et al. (2024). Genome-wide sequence divergence of satellite DNA could underlie meiotic failure in male hybrids of bighead catfish and North African catfish (Clarias, Clariidae). Genomics 116 (4), 110868. 10.1016/j.ygeno.2024.110868 PubMed DOI

Lu M., Li Z., Zhu Z. Y., Peng F., Wang Y., Li X. Y., et al. (2022). Changes in ploidy drive reproduction transition and genomic diversity in a polyploid fish complex. Mol. Biol. Evol. 39 (9), msac188. 10.1093/molbev/msac188 PubMed DOI PMC

Lukhtanov V. A., Dincă V., Friberg M., Vila R., Wiklund C. (2020). Incomplete sterility of chromosomal hybrids: implications for karyotype evolution and homoploid hybrid speciation. Front. Genet. 11, 583827. 10.3389/fgene.2020.583827 PubMed DOI PMC

Lutes A. A., Neaves W. B., Baumann D. P., Wiegraebe W., Baumann P. (2010). Sister chromosome pairing maintains heterozygosity in parthenogenetic lizards. Nature 464 (7286), 283–286. 10.1038/nature08818 PubMed DOI PMC

Macgregor H. C., Uzzell T. M., Jr (1964). Gynogenesis in salamanders related to Ambystoma jeffersonianum . Science 143 (3610), 1043–1045. 10.1126/science.143.3610.1043 PubMed DOI

Majtánová Z., Dedukh D., Choleva L., Adams M., Ráb P., Unmack P. J., et al. (2021). Uniparental genome elimination in Australian carp gudgeons. Genome Biol. Evol. 13 (6), evab030. 10.1093/gbe/evab030 PubMed DOI PMC

Maneechot N., Yano C. F., Bertollo L. A. C., Getlekha N., Molina W. F., Ditcharoen S., et al. (2016). Genomic organization of repetitive DNAs highlights chromosomal evolution in the genus Clarias (Clariidae, Siluriformes). Mol. Cytogenet. 9, 4–10. 10.1186/s13039-016-0215-2 PubMed DOI PMC

Marta A., Tichopád T., Bartoš O., Klíma J., Shah M. A., Bohlen V. Š., et al. (2023). Genetic and karyotype divergence between parents affect clonality and sterility in hybrids. Elife 12, RP88366. 10.7554/eLife.88366 PubMed DOI PMC

Matute D. R., Butler I. A., Turissini D. A., Coyne J. A. (2010). A test of the snowball theory for the rate of evolution of hybrid incompatibilities. Science 329 (5998), 1518–1521. 10.1126/science.1193440 PubMed DOI

Mogie M. (2013). Premeiotic endomitosis and the costs and benefits of asexual reproduction. Biol. J. Linn. Soc. 109 (2), 487–495. 10.1111/bij.12055 DOI

Monaco P. J., Rasch E. M., Balsano J. S. (1984). “Apomictic reproduction in the Amazon molly, Poecilia formosa, and its triploid hybrids,” in Evolutionary genetics of fishes. Editor Turner B. J. (New York, NY: Springer; ), 311–328. 10.1007/978-1-4684-4652-4_6 DOI

Na-Nakorn U., Rangsin W., Boon-ngam J. (2004). Allotriploidy increases sterility in the hybrid between Clarias macrocephalus and Clarias gariepinus . Aquaculture 237 (1–4), 73–88. 10.1016/j.aquaculture.2004.02.032 DOI

Neaves W. B., Baumann P. (2011). Unisexual reproduction among vertebrates. Trends Genet. 27 (3), 81–88. 10.1016/j.tig.2010.12.002 PubMed DOI

Newton A. A., Schnittker R. R., Yu Z., Munday S. S., Baumann D. P., Neaves W. B., et al. (2016). Widespread failure to complete meiosis does not impair fecundity in parthenogenetic whiptail lizards. Development 143 (23), 4486–4494. 10.1242/dev.141283 PubMed DOI PMC

Nguyen D. H., Panthum T., Ponjarat J., Laopichienpong N., Kraichak E., Singchat W., et al. (2021a). An investigation of ZZ/ZW and XX/XY sex determination systems in North African catfish (Clarias gariepinus, burchell, 1822). Front. Genet. 11, 562856. 10.3389/fgene.2020.562856 PubMed DOI PMC

Nguyen D. H., Ponjarat J., Laopichienpong N., Kraichak E., Panthum T., Singchat W., et al. (2021b). Genome-wide SNP analysis suggests male heterogamety in bighead catfish (Clarias macrocephalus,). Aquaculture 543, 737005. 10.1016/j.aquaculture.2021.737005 DOI

Nguyen D. H., Ponjarat J., Laopichienpong N., Panthum T., Singchat W., Ahmad S. F., et al. (2022). Genome-wide SNP analysis of hybrid clariid fish reflects the existence of polygenic sex-determination in the lineage. Front. Genet. 13, 789573. 10.3389/fgene.2022.789573 PubMed DOI PMC

Ozaki Y., Saito K., Shinya M., Kawasaki T., Sakai N. (2011). Evaluation of Sycp3 , Plzf and Cyclin B3 expression and suitability as spermatogonia and spermatocyte markers in zebrafish. Gene Expr. Patterns. 11 (5–6), 309–315. 10.1016/j.gep.2011.03.002 PubMed DOI

Patta C., Panthum T., Thatukan C., Wongloet W., Chalermwong P., Wattanadilokchatkun P., et al. (2024). Questioning inbreeding: could outbreeding affect productivity in the North African catfish in Thailand? PLoS One 19 (5), e0302584. 10.1371/journal.pone.0302584 PubMed DOI PMC

Peters A. H., Plug A. W., Van Vugt M. J., De Boer P. (1997). A drying-down technique for the spreading of mammalian meiocytes from the male and female germline. Chromosome Res. 5 (1), 66–68. 10.1023/a:1018445520117 PubMed DOI

Ponjarat J., Singchat W., Monkheang P., Suntronpong A., Tawichasri P., Sillapaprayoon S., et al. (2019). Evidence of dramatic sterility in F1 male hybrid catfish [male Clarias gariepinus (Burchell, 1822) × female C. macrocephalus (Günther, 1864)] resulting from the failure of homologous chromosome pairing in meiosis I. Aquaculture 505, 84–91. 10.1016/j.aquaculture.2019.02.035 DOI

Pouyaud L., Sudarto, Paradis E. (2009). The phylogenetic structure of habitat shift and morphological convergence in Asian Clarias (Teleostei, Siluriformes: Clariidae). J. Zool. Syst. Evol. Res. 47 (4), 344–356. 10.1111/j.1439-0469.2008.00507.x DOI

Qu W., Liu C., Xu Y. T., Xu Y. M., Luo M. C. (2021). The formation and repair of DNA double-strand breaks in mammalian meiosis. Asian J. Androl. 23 (6), 572–579. 10.4103/aja202191 PubMed DOI PMC

Saito K., Sakai C., Kawasaki T., Sakai N. (2014). Telomere distribution pattern and synapsis initiation during spermatogenesis in zebrafish. Dev. Dynam. 243 (11), 1448–1456. 10.1002/dvdy.24166 PubMed DOI

Schön I., Martens K., van Dijk P. (2009). Lost sex. The evolutionary biology of parthenogenesis (New York: Springer; ).

Shimizu Y., Shibata N., Sakaizumi M., Yamashita M. (2000). Production of diploid eggs through premeiotic endomitosis in the hybrid medaka between Oryzias latipes and O. curvinotus . Zool. Sci. 17, 951–958. 10.2108/zsj.17.951 DOI

Spangenberg V., Arakelyan M., Galoyan E., Matveevsky S., Petrosyan R., Bogdanov Y., et al. (2017). Reticulate evolution of the rock lizards: meiotic chromosome dynamics and spermatogenesis in diploid and triploid males of the genus Darevskia . Genes 8 (6), 149. 10.3390/genes8060149 PubMed DOI PMC

Spangenberg V., Arakelyan M., Simanovsky S., Dombrovskaya Y., Khachatryan E., Kolomiets O. (2024). Tendency towards clonality: deviations of meiosis in parthenogenetic Caucasian rock lizards. Research Square. 10.21203/rs.3.rs-3936576/v2 DOI

Stenberg P., Saura A. (2009). “Cytology of asexual animals,” in Lost sex: the evolutionary biology of parthenogenesis. Editors Schön I., Martens K., van Dijk P. (New York: Springer; ), 63–74.

Stöck M., Dedukh D., Reifová R., Lamatsch D. K., Starostová Z., Janko K. (2021). Sex chromosomes in meiotic, hemiclonal, clonal and polyploid hybrid vertebrates: along the ‘extended speciation continuum. Philos. T. R. Soc. B. 376 (1833), 20200103. 10.1098/rstb.2020.0103 PubMed DOI PMC

Stöck M., Lamatsch D. K., Steinlein C., Epplen J. T., Grosse W. R., Hock R., et al. (2002). A bisexually reproducing all-triploid vertebrate. Nat. Genet. 30 (3), 325–328. 10.1038/ng839 PubMed DOI

Tichopád T., Franěk R., Doležálková-Kaštánková M., Dedukh D., Marta A., Halačka K., et al. (2022). Clonal gametogenesis is triggered by intrinsic stimuli in the hybrid’s germ cells but is dependent on sex differentiation. Biol. Reprod. 107 (2), 446–457. 10.1093/biolre/ioac074 PubMed DOI

Yamashita M., Jiang J., Onozato H., Nakanishi T., Nagahama Y. (1993). A tripolar spindle formed at meiosis I assures the retention of the original ploidy in the gynogenetic triploid crucian carp, Ginbuna Carassius auratus langsdorfii . Dev. Growth Differ. 35 (6), 631–636. 10.1111/j.1440-169X.1993.00631.x PubMed DOI

Yang Z. A., Li Q. H., Wang Y. F., Gui J. F. (1999). Comparative investigation on spindle behavior and MPF activity changes during oocyte maturation between gynogenetic and amphimictic crucian carp. Cell Res. 9 (2), 145–154. 10.1038/sj.cr.7290012 PubMed DOI

Yoshikawa H., Morishima K., Fujimoto T., Saito T., Kobayashi T., Yamaha E., et al. (2009). Chromosome doubling in early spermatogonia produces diploid spermatozoa in a natural clonal fish. Biol. Reprod. 80 (5), 973–979. 10.1095/biolreprod.108.075150 PubMed DOI

Yoshikawa H., Morishima K., Kusuda S., Yamaha E., Arai K. (2007). Diploid sperm produced by artificially sex-reversed Clone loaches. J. Exp. Zool. Part A Ecol. Genet. Physiol. 307A, 75–83. 10.1002/jez.a.337 PubMed DOI