XX/XY sex chromosome system and chromosome markers in the snake eel Ophisurus serpens (Anguilliformes: Ophichtidae)

Susanna Salvadori

Investigation

;Anna Maria Deiana

Investigation

;Federica Deidda

Investigation

;Cinzia Lobina

Investigation

;Antonello Mulas

Resources

;Elisabetta Coluccia

Investigation

2018-01-01

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Abstract

We report evidence of an XX/XY sex chromosome system in the snake eel Ophisurus serpens (Anguilliformes: Ophichthidae). We characterized the male and female karyotypes by C-, replication- and Hae III-bandings. The 45S and 5S ribosomal gene families were located using dual fluorescence in situ hybridization, which showed that the 5S rDNA sites were present on the X chromosome, beside an autosome pair. FISH with a telomeric peptide nucleic acid probe enabled recognition of Interstitial Telomeric Sequences (ITSs), likely remnants of chromosomal rearrangements, in five chromosome pairs, including the rDNA-bearing ones. Possible mechanisms of the origin of sex chromosomes in this species are discussed, considering the presence of a sex-linked marker and ITSs.