title: A Simultaneous Genetic Screen for Zygotic and Sterile Mutants in a Hermaphroditic Vertebrate (Kryptolebias marmoratus).
abstract: The mangrove killifish, Kryptolebias marmoratus, is unique among vertebrates due to its self-fertilizing mode of reproduction involving an ovotestis. As a result, it constitutes a simplistic and desirable vertebrate model for developmental genetics as it is easily maintained, reaches sexual maturity in about 100 days, and provides a manageable number of relatively clear embryos. After the establishment and characterization of an initial mutagenesis pilot screen using N-ethyl-N-nitrosourea, a three-generation genetic screen was performed to confirm zygotic mutant allele heritability and simultaneously score for homozygous recessive mutant sterile F2 fish. From a total of 307 F2 fish screened, 10 were found to be 1° males, 16 were sterile, 92 wild-type, and the remaining 189, carriers of zygotic recessive alleles. These carriers produced 25% progeny exhibiting several zygotic phenotypes similar to those previously described in zebrafish and in the aforementioned pilot screen, as expected. Interestingly, new phenotypes such as golden yolk, no trunk, and short tail were observed. The siblings of sterile F2 mutants were used to produce an F3 generation in order to confirm familial sterility. Out of the 284 F3 fish belonging to 10 previously identified sterile families, 12 were found to be 1° males, 69 were wild-type, 83 sterile, and 120 were classified as */+ (either wild-type or carriers) with undefined genotypes. This screen provides proof of principle that K. marmoratus is a powerful vertebrate model for developmental genetics and can be used to identify mutations affecting fertility.
authors.affiliation: Department of Biology, Valdosta State University, Georgia 31698 Agrobiotechnology Laboratory, National Institute for Agricultural Technology (INTA), Balcarce 7620, Buenos Aires, Argentina.
authors.forename: Sofia
authors.initials: S
authors.lastname: Sucar
authors.affiliation: Department of Biology, Valdosta State University, Georgia 31698 Department of Neurosurgery, University of Florida, McKnight Brain Institute, Gainesville, Florida 32610.
authors.forename: Ginger L
authors.initials: GL
authors.lastname: Moore
authors.affiliation: Department of Biology, Valdosta State University, Georgia 31698 Whitney Laboratory for Marine Bioscience, Department of Biology, St Augustine, Florida 32080.
authors.forename: Melissa E
authors.initials: ME
authors.lastname: Ard
authors.affiliation: Department of Biology, Valdosta State University, Georgia 31698 bcring@valdosta.edu.
authors.forename: Brian C
authors.initials: BC
authors.lastname: Ring
mesh_terms: D000818:Animals; D004625:Embryo, Nonmammalian; D047108:Embryonic Development / Q000235:genetics; D005399:Fishes / Q000235:genetics*; D056084:Genetic Fitness; D005820:Genetic Testing; D057850:Hermaphroditic Organisms / Q000235:genetics*; D009154:Mutation; D010641:Phenotype; D015053:Zygote / Q000378:metabolism*
keywords: ENU mutagenesis; Kryptolebias marmoratus; forward genetic screen; sterile mutant; zygotic mutant