Deciphering the Origin and Evolution of the X1X2Y System in Two Closely-Related Oplegnathus Species (Oplegnathidae and Centrarchiformes)

Author(s)

Xu, Dongdong ^{[1, 2]} ; Sember, Alexandr ^[3] ; Zhu, Qihui ^[1] ; de Oliveira, Ezequiel Aguiar ^{[4, 5]} ; Liehr, Thomas ^[6] ; Al-Rikabi, Ahmed B. H. ^[6] ; Xiao, Zhizhong ^[7] ; Song, Hongbin ^{[1, 2]} ; Cioffi, Marcelo de Bello ^{[4, 6]}

Affiliation

^[1] Marine Fishery Inst Zhejiang Prov, Key Lab Mariculture & Enhancement Zhejiang Prov, Zhoushan 316100 - Peoples R China

^[2] Zhejiang Ocean Univ, Coll Fisheries, Zhoushan 316100 - Peoples R China

^[3] Czech Acad Sci, Lab Fish Genet, Inst Anim Physiol & Genet, Rumburska 89, Libechov 27721 - Czech Republic

^[4] Univ Fed Sao Carlos UFSCar, Dept Genet & Evolucao, Rodovia Washington Luiz Km 235, CP 676, BR-13565905 Sao Carlos, SP - Brazil

^[5] Secretaria Estado Educ Mato Grosso SEDUC MT, BR-78049909 Cuiaba, MT - Brazil

^[6] Univ Clin Jena, Inst Human Genet, D-07747 Jena - Germany

^[7] Chinese Acad Sci, Lab Marine Biol & Biotechnol, Inst Oceanol, 7 Nanhai Rd, Qingdao 266071, Shandong - Peoples R China

• Document type: Journal article
• Source: INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES; v. 20, n. 14 JUL 2 2019.
• Web of Science Citations: 1

Abstract

Oplegnathus fasciatus and 0. punctatus (Teleostei: Centrarchiformes: Oplegnathidae), are commercially important rocky reef fishes, endemic to East Asia. Both species present an X1X2Y sex chromosome system. Here, we investigated the evolutionary forces behind the origin and differentiation of these sex chromosomes, with the aim to elucidate whether they had a single or convergent origin. To achieve this, conventional and molecular cytogenetic protocols, involving the mapping of repetitive DNA markers, comparative genomic hybridization (CGH), and whole chromosome painting (WCP) were applied. Both species presented similar 2n, karyotype structure and hybridization patterns of repetitive DNA classes. 5S rDNA loci, besides being placed on the autosomal pair 22, resided in the terminal region of the long arms of both X1 chromosomes in females, and on the X1 and Y chromosomes in males. Furthermore, WCP experiments with a probe derived from the Y chromosome of O. fasciatus (OFAS-Y) entirely painted the X1 and X2 chromosomes in females and the X1, X2, and Y chromosomes in males of both species. CGH failed to reveal any sign of sequence differentiation on the Y chromosome in both species, thereby suggesting the shared early stage of neo-Y chromosome differentiation. Altogether, the present findings confirmed the origin of the X1X2Y sex chromosomes via Y-autosome centric fusion and strongly suggested their common origin. (AU)

• FAPESP's process: 18/22033-1 - An intercontinental approach for the investigation of chromosome evolution, genetic diversity and biogeography in the order Osteoglossiformes (Teleostei: osteoglossomorpha). Part III
• Grantee: Marcelo de Bello Cioffi
• Support type: Regular Research Grants