1st Edition

Sex Determination in Fish

By T. J. Pandian Copyright 2012
    294 Pages
    by CRC Press

    294 Pages
    by CRC Press

    This book is the first to report that research in allogenics/xenogenics has conclusively shown that fishes have retained bisexual potency even after sexual maturity and spermiation. The XY genotype found in the unexpected female phenotypes sired by supermales (Y1Y2) and androgenic males (Y2Y2) points out the need to employ sex specific molecular markers to identify the true genotype of a juvenile, which matures either as a male or female, depending upon the sex of its pair (female or male) and thereby critically assessing the environmental role in sex determination. This book is meant to assist molecular biologists in the search of sex determining gene(s), fishery biologists endeavouring to develop techniques for profitable monosex aquaculture and ecologists interested in conservation of fishes and their genomes.

    Gonadal origin, eggs and sperm; Chromosomes and heterogamety; Prevalence of gonochorism; Escape from Muller’s ratchet; Multiple parentage and genetic diversity; Prelude
    Cytogenetics and Sex Chromosomes
    Chromosomes and genomes; Cytogenetics; Heterogamety
    Hybridization and Sex Ratio
    Extent of hybridizations; Hybrid identification; Viability and fertility; Introgressive hybridization; Sex ratio
    Gynogenesis and Consequences
    Gynogenics types; Purity of gynogenics; Survival and gamety; Fertility and F1 sex ratio; Sex ratio and departures
    Androgenesis and Autosomes
    Production methods; Survival; Fertility; Overriding autosomes
    Triploidy and sterility
    Types of triploids; Survival and sex ratio; Male’s fertilizability; Female sterility
    Tetraploidy and polyploidy
    Survey and history; Scope for polyploidization; Tetraploid types; True induced tetraploids; Polyploidy; Intraploid hybridizations; Unreduced "gamete bank"
    Allogenesis and xenogenesis
    Primordial Germ Cells (PGCs); PGC transplantation system; PGCs in hybrid embryos; PGCs in heterospecific embryos; Spermatogonial Stem Cells (SSCs); Renewal of SSCs; SSC transplantation system; Relevance of PGCs and SSCs; Surgical gonadectomy
    Sex changers and hermaphroditism
    Extant of hermaphroditism; Sex change in gonochores; Sex allocation; Sex changing age; Genetic or environment?
    Unisexualism and reproductive modes
    Mutational meltdown; Exploration of reproductive modes; Squalius alburnoides; Males in unisexuals
    Genetic sex determination
    Molecular markers; Sex chromosomes; Sexonomics; Sex changers; Polygenic sex determination; Concluding remarks


    T. J. Pandian