Tripathi N, Hoffmann M, Willing EM, Lanz C, Weigel D, Dreyer C. Genetic linkage map of the guppy, Poecilia reticulata, and quantitative trait loci analysis of male size and colour variation. Proc R Soc Lond B 276: 2195-2208

Article (PDF Available)inProceedings of the Royal Society B: Biological Sciences 276(1665):2195-208 · April 2009with39 Reads
DOI: 10.1098/rspb.2008.1930 · Source: PubMed
We report construction of a genetic linkage map of the guppy genome using 790 single nucleotide polymorphism markers, integrated from six mapping crosses. The markers define 23 linkage groups (LGs), corresponding to the known haploid number of guppy chromosomes. The map, which spans a genetic length of 899 cM, includes 276 markers linked to expressed genes (expressed sequence tag), which have been used to derive broad syntenic relationships of guppy LGs with medaka chromosomes. This combined linkage map should facilitate the advancement of genetic studies for a wide variety of complex adaptive phenotypes relevant to natural and sexual selection in this species. We have used the linkage data to predict quantitative trait loci for a set of variable male traits including size and colour pattern. Contributing loci map to the sex LG for many of these traits.


    • "Naturally occurring ESR (i.e., in the absence of chemicals) is known to occur in guppies (Mag-Muresan et al. 2004). The widespread application of sex-specific genetic markers (Khoo et al. 2003; Tripathi et al. 2009) to wild guppy populations may reveal the frequency of naturally occurring feminization, although we note that ESR studies in wild fish populations must be interpreted with caution (see the section Studying ESR in Wild Fish Populations above). Laboratory studies may also provide evidence for the hypothesis that ESR breaks Y-linkage of color genes in guppies; such a study is discussed below in the section Could ESR be a " Fountain of Youth " for Sex Chromosomes? "
    [Show abstract] [Hide abstract] ABSTRACT: Environmental sex reversal (ESR), which results in a mismatch between genotypic and phenotypic sex, is well documented in numerous fish species and may be induced by chemical exposure. Historically, research involving piscine ESR has been carried out with a view to improving profitability in aquaculture or to elucidate the processes governing sex determination and sexual differentiation. However, recent studies in evolution and ecology suggest research on ESR now has much wider applications and ramifications. We begin with an overview of ESR in fish and a brief review of the traditional applications thereof. We then discuss ESR and its potential demographic consequences in wild populations. Theory even suggests sex-reversed fish may be purposefully released to manipulate population dynamics. We suggest new research directions that may prove fruitful in understanding how ESR at the individual level translates to population-level processes. In the latter portion of the review we focus on evolutionary applications of ESR. Sex-reversal studies from the aquaculture literature provide insight in to the evolvability of determinants of sexual phenotype. Additionally, induced sex reversal can provide information about the evolution of sex chromosomes and sex-linked traits. Recently, naturally occurring ESR has been implicated as a mechanism contributing to the evolution of sex chromosomes.
    Full-text · Article · Mar 2015
    • "In guppy males, a more complex control of pigmentation pattern has been observed (Tripathi et al., 2009), including a phenotype characterized by multi-colored areas with an ornamental function involved in female choice and in male mating success, and therefore, important for male fitness. In the genome of this fish, using interval mapping and the multiple-QTL model, 49 QTLs for 11 areas of pigmentation traits were found (see Table 3), which explain 9.4 to 26.8% of phenotypic variation in these traits. "
    [Show abstract] [Hide abstract] ABSTRACT: Appearance traits in fish, those external body characteristics that influence consumer acceptance at point of sale, have come to the forefront of commercial fish farming, as culture profitability is closely linked to management of these traits. Appearance traits comprise mainly body shape and skin pigmentation. Analysis of the genetic basis of these traits in different fish reveals significant genetic variation within populations, indicating potential for their genetic improvement. Work into ascertaining the minor or major genes underlying appearance traits for commercial fish is emerging, with substantial progress in model fish in terms of identifying genes that control body shape and skin colors. In this review, we describe research progress to date, especially with regard to commercial fish, and discuss genomic findings in model fish in order to better address the genetic basis of the traits. Given that appearance traits are important in commercial fish, the genomic information related to this issue promises to accelerate the selection process in coming years.
    Full-text · Article · Aug 2014
    • "Currently, the fusion we document in Lucania (between chromosomes that are syntenic to medaka 3 and 11) is unique among related fish species for which linkage maps exist. Guppies (Poecilia reticulata) also possess a fused chromosome, but it has occurred between two chromosomes that are syntenic to medaka 2 and 21 (Tripathi et al. 2009). Tilapia (Oreochromis niloticus) possess two fused chromosomes: one between chromosomes that are syntenic to medaka 2 and 4, and another between chromosomes syntenic to medaka 6 and 12 (Liu et al. 2013). "
    [Show abstract] [Hide abstract] ABSTRACT: Linkage maps are important tools in evolutionary genetics and in studies of speciation. We performed a karyotyping study and constructed high-density linkage maps for two closely related killifish species, Lucania parva and Lucania goodei, that differ in salinity tolerance and still hybridize in their contact zone in Florida. Using SNPs from orthologous EST contigs, we compared synteny between the two species to determine how genomic architecture has shifted with divergence. Karyotyping revealed that L. goodei possesses 24 acrocentric chromosomes (1N) while L. parva possesses 23 chromosomes (1N), one of which is a large metacentric chromosome. Likewise, high-density SNP-based linkage maps indicated 24 linkage groups for L. goodei and 23 linkage groups for L. parva. Synteny mapping revealed two linkage groups in L. goodei that were highly syntenic with the largest linkage group in L. parva. Together, this evidence points to the largest linkage group in L. parva being the result of a chromosomal fusion. We further compared synteny between Lucania with the genome of a more distant teleost relative medaka (Oryzias latipes) and found good conservation of synteny at the chromosomal level. Each Lucania linkage group had a single best match with each medaka chromosome. These results provide the groundwork for future studies on the genetic architecture of reproductive isolation and salinity tolerance in Lucania and other Fundulidae.
    Full-text · Article · Jun 2014
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