@article{SchedinaGrothSchluppetal.2018,
  author    = {Schedina, Ina Maria and Groth, Detlef and Schlupp, Ingo and Tiedemann, Ralph},
  title     = {The gonadal transcriptome of the unisexual Amazon molly Poecilia formosa in comparison to its sexual ancestors, Poecilia mexicana and Poecilia latipinna},
  series = {BMC Genomics},
  volume    = {19},
  journal   = {BMC Genomics},
  number    = {12},
  publisher = {BioMed Central},
  address   = {London},
  issn      = {1471-2164},
  doi       = {10.1186/s12864-017-4382-2},
  pages     = {1 -- 18},
  year      = {2018},
  abstract  = {Background The unisexual Amazon molly (Poecilia formosa) originated from a hybridization between two sexual species, the sailfin molly (Poecilia latipinna) and the Atlantic molly (Poecilia mexicana). The Amazon molly reproduces clonally via sperm-dependent parthenogenesis (gynogenesis), in which the sperm of closely related species triggers embryogenesis of the apomictic oocytes, but typically does not contribute genetic material to the next generation. We compare for the first time the gonadal transcriptome of the Amazon molly to those of both ancestral species, P. mexicana and P. latipinna. Results We sequenced the gonadal transcriptomes of the P. formosa and its parental species P. mexicana and P. latipinna using Illumina RNA-sequencing techniques (paired-end, 100 bp). De novo assembly of about 50 million raw read pairs for each species was performed using Trinity, yielding 106,922 transcripts for P. formosa, 115,175 for P. latipinna, and 133,025 for P. mexicana after eliminating contaminations. On the basis of sequence similarity comparisons to other teleost species and the UniProt databases, functional annotation, and differential expression analysis, we demonstrate the similarity of the transcriptomes among the three species. More than 40\% of the transcripts for each species were functionally annotated and about 70\% were assigned to orthologous genes of a closely related species. Differential expression analysis between the sexual and unisexual species uncovered 2035 up-regulated and 564 down-regulated genes in P. formosa. This was exemplary validated for six genes by qRT-PCR. Conclusions We identified more than 130 genes related to meiosis and reproduction within the apomictically reproducing P. formosa. Overall expression of these genes seems to be down-regulated in the P. formosa transcriptome compared to both ancestral species (i.e., 106 genes down-regulated, 29 up-regulated). A further 35 meiosis and reproduction related genes were not found in the P. formosa transcriptome, but were only expressed in the sexual species. Our data support the hypothesis of general down-regulation of meiosis-related genes in the apomictic Amazon molly. Furthermore, the obtained dataset and identified gene catalog will serve as a resource for future research on the molecular mechanisms behind the reproductive mode of this unisexual species.},
  language  = {en}
}
@misc{SchedinaGrothSchluppetal.2018,
  author    = {Schedina, Ina Maria and Groth, Detlef and Schlupp, Ingo and Tiedemann, Ralph},
  title     = {The gonadal transcriptome of the unisexual Amazon molly Poecilia formosa in comparison to its sexual ancestors, Poecilia mexicana and Poecilia latipinna},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-409299},
  pages     = {18},
  year      = {2018},
  abstract  = {Abstract Background The unisexual Amazon molly (Poecilia formosa) originated from a hybridization between two sexual species, the sailfin molly (Poecilia latipinna) and the Atlantic molly (Poecilia mexicana). The Amazon molly reproduces clonally via sperm-dependent parthenogenesis (gynogenesis), in which the sperm of closely related species triggers embryogenesis of the apomictic oocytes, but typically does not contribute genetic material to the next generation. We compare for the first time the gonadal transcriptome of the Amazon molly to those of both ancestral species, P. mexicana and P. latipinna. Results We sequenced the gonadal transcriptomes of the P. formosa and its parental species P. mexicana and P. latipinna using Illumina RNA-sequencing techniques (paired-end, 100 bp). De novo assembly of about 50 million raw read pairs for each species was performed using Trinity, yielding 106,922 transcripts for P. formosa, 115,175 for P. latipinna, and 133,025 for P. mexicana after eliminating contaminations. On the basis of sequence similarity comparisons to other teleost species and the UniProt databases, functional annotation, and differential expression analysis, we demonstrate the similarity of the transcriptomes among the three species. More than 40\% of the transcripts for each species were functionally annotated and about 70\% were assigned to orthologous genes of a closely related species. Differential expression analysis between the sexual and unisexual species uncovered 2035 up-regulated and 564 down-regulated genes in P. formosa. This was exemplary validated for six genes by qRT-PCR. Conclusions We identified more than 130 genes related to meiosis and reproduction within the apomictically reproducing P. formosa. Overall expression of these genes seems to be down-regulated in the P. formosa transcriptome compared to both ancestral species (i.e., 106 genes down-regulated, 29 up-regulated). A further 35 meiosis and reproduction related genes were not found in the P. formosa transcriptome, but were only expressed in the sexual species. Our data support the hypothesis of general down-regulation of meiosis-related genes in the apomictic Amazon molly. Furthermore, the obtained dataset and identified gene catalog will serve as a resource for future research on the molecular mechanisms behind the reproductive mode of this unisexual species.},
  language  = {en}
}
@article{ZhuSchluppTiedemann2016,
  author    = {Zhu, Fangjun and Schlupp, Ingo and Tiedemann, Ralph},
  title     = {Sequence Evolution and Expression of the Androgen Receptor and Other Pathway-Related Genes in a Unisexual Fish, the Amazon Molly, Poecilia formosa, and Its Bisexual Ancestors},
  series = {PLoS one},
  volume    = {11},
  journal   = {PLoS one},
  publisher = {PLoS},
  address   = {San Fransisco},
  issn      = {1932-6203},
  doi       = {10.1371/journal.pone.0156209},
  pages     = {19},
  year      = {2016},
  abstract  = {The all-female Amazon molly (Poecilia formosa) originated from a single hybridization of two bisexual ancestors, Atlantic molly (Poecilia mexicana) and sailfin molly (Poecilia latipinna). As a gynogenetic species, the Amazon molly needs to copulate with a heterospecific male, but the genetic information of the sperm-donor does not contribute to the next generation, as the sperm only acts as the trigger for the diploid eggs' embryogenesis. Here, we study the sequence evolution and gene expression of the duplicated genes coding for androgen receptors (ars) and other pathway-related genes, i.e., the estrogen receptors (ers) and cytochrome P450, family19, subfamily A, aromatase genes (cyp19as), in the Amazon molly, in comparison to its bisexual ancestors. Mollies possess-as most other teleost fish—two copies of the ar, er, and cyp19a genes, i.e., ar\&\#945;/ar\&\#946;, er\&\#945;/er\&\#946;1, and cyp19a1 (also referred as cyp19a1a)/cyp19a2 (also referred to as cyp19a1b), respectively. Non-synonymous single nucleotide polymorphisms (SNPs) among the ancestral bisexual species were generally predicted not to alter protein function. Some derived substitutions in the P. mexicana and one in P. formosa are predicted to impact protein function. We also describe the gene expression pattern of the ars and pathway-related genes in various tissues (i.e., brain, gill, and ovary) and provide SNP markers for allele specific expression research. As a general tendency, the levels of gene expression were lowest in gill and highest in ovarian tissues, while expression levels in the brain were intermediate in most cases. Expression levels in P. formosa were conserved where expression did not differ between the two bisexual ancestors. In those cases where gene expression levels significantly differed between the bisexual species, P. formosa expression was always comparable to the higher expression level among the two ancestors. Interestingly, er\&\#946;1 was expressed neither in brain nor in gill in the analyzed three molly species, which implies a more important role of er\&\#945; in the estradiol synthesis pathway in these tissues. Furthermore, our data suggest that interactions of steroid-signaling pathway genes differ across tissues, in particular the interactions of ars and cyp19as.},
  language  = {en}
}
@article{ZhuSchluppTiedemann2016,
  author    = {Zhu, Fangjun and Schlupp, Ingo and Tiedemann, Ralph},
  title     = {Sequence Evolution and Expression of the Androgen Receptor and Other Pathway-Related Genes in a Unisexual Fish, the Amazon Molly, Poecilia formosa, and Its Bisexual Ancestors},
  series = {PLoS one},
  volume    = {11},
  journal   = {PLoS one},
  number    = {6},
  publisher = {PLoS},
  address   = {Lawrence, Kan.},
  issn      = {1932-6203},
  doi       = {10.1371/JOURNAL.PONE.0156209},
  pages     = {19},
  year      = {2016},
  abstract  = {The all-female Amazon molly (Poecilia formosa) originated from a single hybridization of two bisexual ancestors, Atlantic molly (Poecilia mexicana) and sailfin molly (Poecilia latipinna). As a gynogenetic species, the Amazon molly needs to copulate with a heterospecific male, but the genetic information of the sperm-donor does not contribute to the next generation, as the sperm only acts as the trigger for the diploid eggs' embryogenesis. Here, we study the sequence evolution and gene expression of the duplicated genes coding for androgen receptors (ars) and other pathway-related genes, i.e., the estrogen receptors (ers) and cytochrome P450, family19, subfamily A, aromatase genes (cyp19as), in the Amazon molly, in comparison to its bisexual ancestors. Mollies possess-as most other teleost fish—two copies of the ar, er, and cyp19a genes, i.e., arα/arβ, erα/erβ1, and cyp19a1 (also referred as cyp19a1a)/cyp19a2 (also referred to as cyp19a1b), respectively. Non-synonymous single nucleotide polymorphisms (SNPs) among the ancestral bisexual species were generally predicted not to alter protein function. Some derived substitutions in the P. mexicana and one in P. formosa are predicted to impact protein function. We also describe the gene expression pattern of the ars and pathway-related genes in various tissues (i.e., brain, gill, and ovary) and provide SNP markers for allele specific expression research. As a general tendency, the levels of gene expression were lowest in gill and highest in ovarian tissues, while expression levels in the brain were intermediate in most cases. Expression levels in P. formosa were conserved where expression did not differ between the two bisexual ancestors. In those cases where gene expression levels significantly differed between the bisexual species, P. formosa expression was always comparable to the higher expression level among the two ancestors. Interestingly, erβ1 was expressed neither in brain nor in gill in the analyzed three molly species, which implies a more important role of erα in the estradiol synthesis pathway in these tissues. Furthermore, our data suggest that interactions of steroid-signaling pathway genes differ across tissues, in particular the interactions of ars and cyp19as.},
  language  = {en}
}
@misc{ZhuSchluppTiedemann2016,
  author    = {Zhu, Fangjun and Schlupp, Ingo and Tiedemann, Ralph},
  title     = {Sequence Evolution and Expression of the Androgen Receptor and Other Pathway-Related Genes in a Unisexual Fish, the Amazon Molly, Poecilia formosa, and Its Bisexual Ancestors},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-97119},
  pages     = {19},
  year      = {2016},
  abstract  = {The all-female Amazon molly (Poecilia formosa) originated from a single hybridization of two bisexual ancestors, Atlantic molly (Poecilia mexicana) and sailfin molly (Poecilia latipinna). As a gynogenetic species, the Amazon molly needs to copulate with a heterospecific male, but the genetic information of the sperm-donor does not contribute to the next generation, as the sperm only acts as the trigger for the diploid eggs' embryogenesis. Here, we study the sequence evolution and gene expression of the duplicated genes coding for androgen receptors (ars) and other pathway-related genes, i.e., the estrogen receptors (ers) and cytochrome P450, family19, subfamily A, aromatase genes (cyp19as), in the Amazon molly, in comparison to its bisexual ancestors. Mollies possess-as most other teleost fish—two copies of the ar, er, and cyp19a genes, i.e., arα/arβ, erα/erβ1, and cyp19a1 (also referred as cyp19a1a)/cyp19a2 (also referred to as cyp19a1b), respectively. Non-synonymous single nucleotide polymorphisms (SNPs) among the ancestral bisexual species were generally predicted not to alter protein function. Some derived substitutions in the P. mexicana and one in P. formosa are predicted to impact protein function. We also describe the gene expression pattern of the ars and pathway-related genes in various tissues (i.e., brain, gill, and ovary) and provide SNP markers for allele specific expression research. As a general tendency, the levels of gene expression were lowest in gill and highest in ovarian tissues, while expression levels in the brain were intermediate in most cases. Expression levels in P. formosa were conserved where expression did not differ between the two bisexual ancestors. In those cases where gene expression levels significantly differed between the bisexual species, P. formosa expression was always comparable to the higher expression level among the two ancestors. Interestingly, erβ1 was expressed neither in brain nor in gill in the analyzed three molly species, which implies a more important role of erα in the estradiol synthesis pathway in these tissues. Furthermore, our data suggest that interactions of steroid-signaling pathway genes differ across tissues, in particular the interactions of ars and cyp19as.},
  language  = {en}
}
@article{RieschSchluppTobleretal.2006,
  author    = {Riesch, R{\"u}diger and Schlupp, Ingo and Tobler, Michael and Plath, Martin},
  title     = {Reduction of the association preference for conspecifics in cave-dwelling Atlantic mollies, Poecilia mexicana},
  series = {Behavioral ecology and sociobiology},
  volume    = {60},
  journal   = {Behavioral ecology and sociobiology},
  publisher = {Springer},
  address   = {New York},
  issn      = {0340-5443},
  doi       = {10.1007/s00265-006-0223-z},
  pages     = {794 -- 802},
  year      = {2006},
  abstract  = {Cave animals are widely recognised as model organisms to study regressive evolutionary processes like the reduction of eyes. In this paper, we report on the regressive evolution of species discrimination in the cave molly, Poecilia mexicana, which, unlike other cave fishes, still has functional eyes. This allowed us to examine the response to both visual and non-visual cues involved in species discrimination. When surface-dwelling females were given a chance to associate with either a conspecific or a swordtail (Xiphophorus hellerii) female, they strongly preferred the conspecific female both when multiple cues and when solely visual cues were available to the female. No association preference was observed when only non-visual cues were provided. In contrast, cave-dwelling females showed no preference under all testing conditions, suggesting that species recognition mechanisms have been reduced. We discuss the role of species discrimination in relation to habitat differences.},
  language  = {en}
}
@article{RieschToblerPlathetal.2009,
  author    = {Riesch, R{\"u}diger and Tobler, Michael and Plath, Martin and Schlupp, Ingo},
  title     = {Offspring number in a livebearing fish (Poecilia mexicana, Poeciliidae) : reduced fecundity and reduced plasticity in a population of cave mollies},
  issn      = {0378-1909},
  doi       = {10.1007/s10641-008-9392-0},
  year      = {2009},
  abstract  = {Life history traits within species often vary among different habitats. We measured female fecundity in mollies (Poecilia mexicana) from a H2S-rich cave and from a neighbouring surface habitat, as well as in laboratory-reared individuals of both populations raised in either light or continuous darkness. Compared to conspecifics from surface habitats, cave-dwelling P. mexicana had reduced fecundity (adjusted for size) in the field. In the laboratory, the fecundity of surface mollies was higher in light than in darkness, whereas fecundity in the cave mollies was almost unaffected by the ambient light conditions. Our results suggest a heritable component to the reduction in fecundity in female cave mollies. Moreover, the reduced plasticity in fecundity of cave mollies in response to light conditions might be an example of genetic assimilation or channelling of a life history trait in a population invading a new environment.},
  language  = {en}
}
@article{TiedemannMollPaulusetal.2005,
  author    = {Tiedemann, Ralph and Moll, K. and Paulus, Kirsten B. and Schlupp, Ingo},
  title     = {New microsatellite loci confirm hybrid origin, parthenogenetic inheritance, and mitotic gene conversion in the gynogenetic Amazon molly (Poecilia formosa)},
  issn      = {1471-8278},
  year      = {2005},
  abstract  = {We describe the first microsatellite loci for the gynogenetic Amazon molly, Poecilia formosa, an all-female species arisen through hybridization of the bisexual species Poecilia mexicana and Poecilia latipinna. The loci showed one to six alleles and an expected heterozygosity between zero and 0.75. As expected with parthenogenetic inheritance, most loci were either constantly homozygous (five loci) or constantly heterozygous (eight loci). For six loci, both heterozygotes and homozygotes occurred. This and the fact that some loci only showed alleles of one of the ancestral species could indicate genome homogenization through mitotic gene conversion. Our new loci conformed to the hybrid origin of Amazon molly and are also applicable to both ancestral bisexual species},
  language  = {en}
}
@article{McCoySyskaPlathetal.2011,
  author    = {McCoy, Ellen and Syska, Norbert and Plath, Martin and Schlupp, Ingo and Riesch, R{\"u}diger},
  title     = {Mustached males in a tropical poeciliid fish - emerging female preference selects for a novel male trait},
  series = {Behavioral ecology and sociobiology},
  volume    = {65},
  journal   = {Behavioral ecology and sociobiology},
  number    = {7},
  publisher = {Springer},
  address   = {New York},
  issn      = {0340-5443},
  doi       = {10.1007/s00265-011-1154-x},
  pages     = {1437 -- 1445},
  year      = {2011},
  abstract  = {One possible mechanism for the (co-)evolution of seemingly novel male traits and female preferences for them is that males exploit pre-existing female biases, and livebearing fishes (Poeciliidae) have been at the forefront of this research for almost two decades. Here, using 13 poeciliid species from four different genera, we tested whether mustache-like rostral filaments found in males of some Mexican molly (Poecilia sphenops) populations could have evolved due to exploitation of a pre-existing female bias. While Mexican mollies were the only species with a significant female association preference for mustached males, we also did not find any species exhibiting significant aversion for mustached males; rather, variance in female preference scores was large throughout. For example, more than 25\% of females spent twice as much time with the mustached male compared to the non-mustached male in most species, but even 31\% of Mexican molly females spent more time near the non-mustached male. Hence, a comparison of the strength of preference was inconclusive. We discuss the possibility that the female preference of P. sphenops for mustached males could be due to a female pre-existing bias (sensu lato), even if population means were not significant for species other than P. sphenops. This highlights the importance of distinguishing between population means and individual preferences when interpreting mate choice, and thus, adds depth to the concept of mating preferences as a motor for evolutionary change.},
  language  = {en}
}
@article{SchererTiedemannSchlupp2018,
  author    = {Scherer, Ulrike and Tiedemann, Ralph and Schlupp, Ingo},
  title     = {Male size, not female preferences influence female reproductive success in a poeciliid fish (Poecilia latipinna)},
  series = {BMC Research Notes},
  volume    = {11},
  journal   = {BMC Research Notes},
  number    = {364},
  publisher = {Biomed Central},
  address   = {London},
  issn      = {1756-0500},
  doi       = {10.1186/s13104-018-3487-2},
  pages     = {1 -- 5},
  year      = {2018},
  abstract  = {Objective We investigated the potential role of indirect benefits for female mate preferences in a highly promiscuous species of live-bearing fishes, the sailfin molly Poecilia latipinna using an integrative approach that combines methods from animal behavior, life-history evolution, and genetics. Males of this species solely contribute sperm for reproduction, and consequently females do not receive any direct benefits. Despite this, females typically show clear mate preferences. It has been suggested that females can increase their reproductive success through indirect benefits from choosing males of higher quality. Results Although preferences for large body size have been recorded as an honest signal for genetic quality, this particular study resulted in female preference being unaffected by male body size. Nonetheless, larger males did sire more offspring, but with no effect on offspring quality. This study presents a methodical innovation by combining preference testing with life history measurements—such as the determination of the dry weight of fish embryos—and paternity analyses on single fish embryos.},
  language  = {en}
}