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ORIGINAL RESEARCH article

Front. Cell Dev. Biol.
Sec. Molecular and Cellular Reproduction
Volume 12 - 2024 | doi: 10.3389/fcell.2024.1465335

Meiotic deviations and endoreplication lead to diploid oocytes in female hybrids between bighead catfish (Clarias macrocephalus) and North African catfish (Clarias gariepinus)

Provisionally accepted
Dmitrij Dedukh Dmitrij Dedukh 1Artem Lisachov Artem Lisachov 2Thitipong Panthum Thitipong Panthum 2Worapong Singchat Worapong Singchat 2Yoichi Matsuda Yoichi Matsuda 2Yukiko Imai Yukiko Imai 3Karel Janko Karel Janko 1Kornsorn Srikulnath Kornsorn Srikulnath 2,4*
  • 1 Institute of Animal Physiology and Genetics, Academy of Sciences of the Czech Republic (ASCR), Prague, Prague, Czechia
  • 2 Animal Genomics and Bioresource Research Unit (AGB Research Unit), Faculty of Science, Kasetsart University, 50 Ngamwongwan, Chatuchak, Bangkok 10900, Thailand, Bangkok, Thailand
  • 3 Department of Gene Function and Phenomics, National Institute of Genetics, Yata 1111, Mishima 411-8540, Mishima, Japan
  • 4 Biodiversity Center Kasetsart University (BDCKU), Bangkok 10900, Thailand, Bangkok, Thailand

The final, formatted version of the article will be published soon.

    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. In this study, 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. 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.

    Keywords: Synaptonemal Complex, lampbrush chromosomes, Telomeric sequence, satellite DNA, Clariid catfish

    Received: 16 Jul 2024; Accepted: 07 Aug 2024.

    Copyright: © 2024 Dedukh, Lisachov, Panthum, Singchat, Matsuda, Imai, Janko and Srikulnath. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence: Kornsorn Srikulnath, Animal Genomics and Bioresource Research Unit (AGB Research Unit), Faculty of Science, Kasetsart University, 50 Ngamwongwan, Chatuchak, Bangkok 10900, Thailand, Bangkok, Thailand

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