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. 2020 Nov 30;24(1):101886.
doi: 10.1016/j.isci.2020.101886. eCollection 2021 Jan 22.

fshr: a fish sex-determining locus shows variable incomplete penetrance across flathead grey mullet populations

Serena Ferraresso  1 , Luca Bargelloni  1 , Massimiliano Babbucci  1 , Rita Cannas  2 , Maria Cristina Follesa  2 , Laura Carugati  2 , Riccardo Melis  2 , Angelo Cau  2 , Manos Koutrakis  3 , Argyrios Sapounidis  3 , Donatella Crosetti  4 , Tomaso Patarnello  1
Affiliations

fshr: a fish sex-determining locus shows variable incomplete penetrance across flathead grey mullet populations

Serena Ferraresso et al. iScience. .

Abstract

Whole-genome sequencing data were produced from a single flathead grey mullet female and assembled into a draft genome sequence, whereas publicly available sequence data were used to obtain a male draft sequence. Two pools, each consisting of 60 unrelated individuals, respectively, of male and female fish were analyzed using Pool-Sequencing. Mapping and analysis of Pool-Seq data against the draft genome(s) revealed >30 loci potentially associated with sex, the most promising locus of which, encoding the follicle-stimulating hormone receptor (fshr) and harboring two missense variants, was genotyped on 245 fish from four Mediterranean populations. Genotype data showed that fshr represents a previously unknown sex-determining locus, although the incomplete association pattern between fshr genotype and sex-phenotype, the variability of such pattern across different populations, and the presence of other candidate loci reveal that a greater complexity underlies sex determination in the flathead grey mullet.

Keywords: Evolutionary Biology; Genetics; Genomics.

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Conflict of interest statement

The authors declare no competing interests.

Figures

None
Graphical abstract
Figure 1
Figure 1
Sampling sites (ORB: Orbetello Lagoon, CAB: Cabras Lagoon, TOR: Tortolì Lagoon, KAV: Kavala).
Figure 2
Figure 2
Female- and male-specific allele frequencies at variable nucleotide positions surrounding the three significant variants The grey square indicates the three variants associated with sex. Distance from MuCe179 variant is showed in y axis; x axis reports variants' allele frequency. On the X-axis, observed frequency of the major allele is shown for each SNP. On the Y-axis, the relative distance in kilobases (kb), respectively upstream and downstream of SNP MuCe179.
Figure 3
Figure 3
Position of the two non-synonymous variants on the fshr sequence and multiple fish species sequence alignment (Dila: Dicentrarchus labrax, Gaac: Gasterosteus aculeatus, Spau: Sparus aurata, Orni: Oreochromis niloticus, MuCe_F: Mugil cephalus wt allele, MuCe_M: m1 allele, Dare: Danio rerio). Nucleotide sequence of the fshr contig and exact positions of MuCe179, MuCe206 and MuCe322 variants are reported in Data S1.
Figure 4
Figure 4
Macroscopic gonad morphology of male and female M. cephalus individuals (A–D) Male individual (A), macroscopic appearance of male (B) and female (C) gonads, and female individual (D).
See this image and copyright information in PMC

References

    1. Chu L., Li J., Liu Y., Cheng C.H. Gonadotropin signaling in zebrafish ovary and testis development: insights from gene knockout study. Mol. Endocrinol. 2015;29:1743–1758. - PMC - PubMed
    1. Crosetti D. Current state of grey mullet fisheries and culture. In: Crosetti D., Blaber S.J.M., editors. Biology, Ecology and Culture of Grey Mullet (Mugilidae) CRC Press; 2016. pp. 398–450.
    1. Dor L., Shirak A., Rosenfeld H., Ashkenazi I.M., Band M.R., Korol A., Ronin Y., Seroussi E., Weller J.I., Ron M. Identification of the sex-determining region in flathead grey mullet (Mugil cephalus) Anim. Genet. 2016;47:698–707. - PubMed
    1. Durand J.D., Borsa P. Mitochondrial phylogeny of grey mullets (Acanthopterygii: Mugilidae) suggests high proportion of cryptic species. C R. Biol. 2015;2338:266–277. - PubMed
    1. Durand J.D., Blel H., Shen K.N., Koutrakis E.T., Guinand B. Population genetic structure of Mugil cephalus in the Mediterranean and Black Seas: a single mitochondrial clade and many nuclear barriers. Mar. Ecol. Prog. Ser. 2013;474:243–261.

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