Methyltestosterone efficiently induces male development in the self‐fertilizing hermaphrodite fish, Kryptolebias marmoratus

  title={Methyltestosterone efficiently induces male development in the self‐fertilizing hermaphrodite fish, Kryptolebias marmoratus},
  author={Akira Kanamori and Aki Yamamura and Satoshi Koshiba and Jae‐Seong Lee and Edward F. Orlando and H. Hori},
A hermaphrodite fish, Kryptolebias marmoratus, is the only known vertebrate that reproduces by self‐fertilization. In nature, males have been rarely observed. Low‐temperature treatment during late embryonic stages is known to induce males but its efficacy is variable. Here we report that 17α‐methyltestosterone (MT) treatment of the embryos converted most of the fish to males. We examined a time course of this male induction with histological and marker gene expression analyses. Oogenesis… 
A Transient Hermaphroditic Stage in Early Male Gonadal Development in Little Yellow Croaker, Larimichthys polyactis
This research is the first report on male-specific transient hermaphroditic stage in little yellow croaker during early gonadal development, and will advance the current understanding of fish reproductive biology.
Embryonic development of the self‐fertilizing mangrove killifish Kryptolebias marmoratus
The data suggest that K. marmoratus embryos are easily used and manipulated, supporting the use of this hermaphroditic vertebrate as a strong comparative model system in embryology, evolution, genetics, environmental and medical biology.
Transient effects of methyltestosterone injection on different reproductive parameters of the hermaphrodite fish Kryptolebias marmoratus
The results clearly show that a single injection of MT inhibits ovarian development rather than testicular development in the hermaphroditic gonad of K. marmoratus, and demonstrate that asingle injection ofMT interfered with hepatic VTG mRNA synthesis mediated by the suppression of hepatic ERα mRNA transcription.
Effects of Temperature on Gene Expression and Sex Determination in the Mangrove Rivulus, Kryptolebias marmoratus
These results provide the first data documenting how temperature affects the expression of genes rel vant to sex determination during embryogenesis in rivulus.
Analysis of expressed sequence tags from the liver and ovary of the euryhaline hermaphroditic fish, Kryptolebias marmoratus.
  • J. RheeBo-Mi Kim Jae-Seong Lee
  • Biology, Environmental Science
    Comparative biochemistry and physiology. Part D, Genomics & proteomics
  • 2011
The Genome of the Self-Fertilizing Mangrove Rivulus Fish, Kryptolebias marmoratus: A Model for Studying Phenotypic Plasticity and Adaptations to Extreme Environments
The genome provides an important addition to the linkage map and transcriptomic tools recently developed for this species that together provide critical resources for epigenetic, transcriptomic, and proteomic analyses and will serve as the foundation for addressing key questions in behavior, physiology, toxicology, and evolutionary biology.
Differential transcript expression of selected gene batteries in two clonal strains of the self-fertilizing fish, Kryptolebias marmoratus.
Establishing developmental genetics in a self-fertilizing fish (Krytolebias marmoratus).
A pilot zygotic mutant screen utilizing the common chemical mutagen, N-ethyl-N-nitrosourea (ENU) is presented to establish genetics in this model species, Kryptolebias marmoratus, to complement future developmental genetic screens in vertebrates.


Two series of experiments were undertaken to identify a possible environmental factor able to cause a deviation to the male phenotype during sex differentiation, on the working hypothesis that low male incidence in clones composed otherwise of hermaphrodites indicated a lability in the sex-determining mechanism through which the genotype normally produces the herMaphrodite phenotype.
Gonadal histology in the self-fertilizing hermaphroditic fish Rivulus marmoratus (Pisces, Cyprinodontidae)
Gonadal structure and the characterization of the stages of spermatogenesis and oogenesis allowed us to categorize functional gender and to construct the probable sequence of gonadal development in mature individuals.
Plasma Sex Steroid Levels and Steroidogenesis in the Gonad of the Self-fertilizing Fish Rivulus marmoratus
It is concluded that both hermaphrodite and primary male of the mangrove killifish secrete estrogen, androgen, and progestin synchronously.
Cloning and differential expression of estrogen receptor and aromatase genes in the self-fertilizing hermaphrodite and male mangrove rivulus, Kryptolebias marmoratus.
The mechanisms underlying sex determination and differentiation in fishes are labile in response to environmental parameters. Sex-specific phenotypes are largely regulated by sex steroids, and the
Oocyte apoptosis during the transition from ovary-like tissue to testes during sex differentiation of juvenile zebrafish.
Oocyte apoptosis is the mechanism of testicular and ovarian differentiation in zebrafish and the decomposition of the ovarian cavity caused by apoptosis during sex differentiation were male-specific events.
The Homozygosity of Clones of the Self-Fertilizing Hermaphroditic Fish Rivulus marmoratus Poey (Cyprinodontidae, Atheriniformes)
Two clones of the hermaphroditic fish Rivulus marmoratus Poey, identified by their intraclonal histocompatibilities and interclonal histoincompatibility, were kept through successive uniparental generations, each fish in isolation to study the possible role of males in the prevalence of homozygous clones in the wild.
How Ecological and Genetic Factors Interact to Determine When Self-Fertilizing Hermaphrodites of Rivulus marmoratus Change into Functional Secondary Males, With a Reappraisal of the Modes of Intersexuality Among Fishes
Testicular activity, measured by percentages of self-fertilized eggs laid, was much lower throughout the hermaphrodite phase of fish early-rearing at low temperature as contrasted with high, but ovarian activity was similar between fish earlyreared at low and at high temperature.
Systematic identification of genes expressed during early oogenesis in medaka
  • A. Kanamori
  • Biology
    Molecular reproduction and development
  • 2000
Subtractive hybridization was used to identify differences in gene expression between medaka (Oryzias latipes) males and females during sex differentiation. Fifty female‐specific cDNA fragments were
Extensive outcrossing and androdioecy in a vertebrate species that otherwise reproduces as a self-fertilizing hermaphrodite.
It is found that outcrossing (probably between gonochoristic males and hermaphrodites) is common at the Belize site, and the dramatic impact that functional androdioecy can have on the population genetic architecture of this reproductively unique vertebrate species is demonstrated.