AUTHOR=Sassi Francisco de Menezes Cavalcante , Deon Geize Aparecida , Sember Alexandr , Liehr Thomas , Oyakawa Osvaldo Takeshi , Moreira Filho Orlando , Bertollo Luiz Antonio Carlos , Vicari Marcelo Ricardo , Cioffi Marcelo de Bello 

TITLE=Turnover of multiple sex chromosomes in Harttia catfish (Siluriformes, Loricariidae): a glimpse from whole chromosome painting

JOURNAL=Frontiers in Genetics

VOLUME=Volume 14 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/genetics/articles/10.3389/fgene.2023.1226222

DOI=10.3389/fgene.2023.1226222

ISSN=1664-8021

ABSTRACT=<p>The remarkable fish biodiversity encompasses also great sex chromosome variability. <italic>Harttia</italic> catfish belong to Neotropical models for karyotype and sex chromosome research. Some species possess one of the three male-heterogametic sex chromosome systems, XY, X<sub>1</sub>X<sub>2</sub>Y or XY<sub>1</sub>Y<sub>2</sub>, while other members of the genus have yet uncharacterized modes of sex determination. Particularly the XY<sub>1</sub>Y<sub>2</sub> multiple sex chromosome system shows a relatively low incidence among vertebrates, and it has not been yet thoroughly investigated. Previous research suggested two independent X-autosome fusions in <italic>Harttia</italic> which led to the emergence of XY<sub>1</sub>Y<sub>2</sub> sex chromosome system in three of its species. In this study, we investigated evolutionary trajectories of synteny blocks involved in this XY<sub>1</sub>Y<sub>2</sub> system by probing six <italic>Harttia</italic> species with whole chromosome painting (WCP) probes derived from the X (HCA-X) and the chromosome 9 (HCA-9) of <italic>H. carvalhoi</italic>. We found that both painting probes hybridize to two distinct chromosome pairs in Amazonian species, whereas the HCA-9 probe paints three chromosome pairs in <italic>H. guianensis,</italic> endemic to Guyanese drainages. These findings demonstrate distinct evolutionary fates of mapped synteny blocks and thereby elevated karyotype dynamics in <italic>Harttia</italic> among the three evolutionary clades.</p>