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bioRxiv · 10.1101/2025.05.19.654947

Genome Report: Genome of the Amazon Guppy (Poecilia bifurca) reveals conservation of sex chromosomes and dosage compensation

Fong, L. J.·Johnson, B. D.·Darolti, I.·Sandkam, B. A.·Mank, J. E.
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Abstract

The Amazon guppy, Poecilia bifurca, is a small live-bearing fish. Closely related species, such as P. reticulata, P. picta, and P. parae all share the same sex chromosome system, but with substantial diversity in the degree of Y degeneration and the extent of X chromosome dosage compensation. We built a female (XX) draft genome with 55X coverage of PacBio HiFi data, resulting in a 785 Mb assembly with 94.4% BUSCO completeness. Using this genome, we found that P. bifurca shares the same sex chromosomes as related species and shows substantial Y chromosome degeneration. We combined this with RNA-Seq data and find similar expression of X-linked genes between sexes, revealing that P. bifurca also exhibits complete X chromosome dosage compensation. We further identify 11 putative autosome-to-Y gene duplications, five of which show gene expression in guppy male germ cells.

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Fong, L. J., Johnson, B. D., Darolti, I., Sandkam, B. A., Mank, J. E.. 2025-05-24. Genome Report: Genome of the Amazon Guppy (Poecilia bifurca) reveals conservation of sex chromosomes and dosage compensation. https://doi.org/10.1101/2025.05.19.654947

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