Induced diploid gynogenesis and polyploidy in the ornamental (koi) carp Cyprinus carpio L.
The results of a series of experiments conducted in our laboratory on the ornamental common carp (koi), aimed at optimizing heat-shock chromosome-set manipulation procedures, are described. The timing of heat-shock initiation was expressed in the relative unit of embryological age (τ0) in order to standardize this parameter, the absolute time for heat-shock initiation being calculated from duration of one τ0 at two different pre-treatment water temperatures. Heat shocks were applied within the periods of 0.05–0.60 τ0 and 1.20–2.20 τ0 which, respectively, cover the successive phases of the 2nd meiotic division and the 1st cleavage. The highest production of diploid gynogenetic offspring was observed when heat shocks were initiated at 0.15–0.25 τ0 and at 1.5 τ0, after insemination, corresponding to anaphase of meiosis-II, and metaphase of the 1st cleavage, respectively. Similar results were obtained irrespective of the different pre-treatment water temperatures, thus confirming the possibility of standardizing heat-shock timing by τ0.
Gynogenesis in common carp (Cyprinus carpio L.): II. The production of homozygous gynogenetic clones and F1 hybrids
Abstract Homozygous gynogenetic fry of common carp (Cyprinus carpio L.) were produced by heat-shocking eggs, activated with UV-irradiated sperm (1 : 3 diluted, 10 ml, at 2200 J m−2 min−1) during metaphase of the first mitosis. Consistent yields of 5–15% viable, gynogenetic fry were obtained when eggs were shocked at 40°C for 2 min, 28–30 min after fertilization. The homozygous nature of the gynogenetic fry was demonstrated by the mendelian segregation patterns of three recessive mutant pigment genes. Homozygous inbred strains were produced by heterozygous gynogenetic reproduction (second polar body retention) of homozygous gynogenetic females, while F1 hybrids were produced by crossing these females with homozygous gynogenetic male siblings. The clonal nature of these strains was unequivocally demonstrated by the acceptance of reciprocally exchanged skin allografts.
History of Amateurism in Men's Intercollegiate Athletics: The Continuance of a 19th-Century Anachronism in America
Claiming that American intercollegiate athletics are amateur at the end of the 20th century is an anachronism, for colleges in the 19th century took on professional characteristics. The upper-class British concept of amateurism did not work effectively in a more egalitarian and achievement-oriented American society. Hypocrisy resulted when colleges claimed amateurism while accepting such professional practices as hiring professional coaches, allowing athletes to play summer baseball for money, and paying athletes through grants-in-aid. Attempts to preserve amateurism, such as the Graham Plan in the 1930s and the Sanity Code in the 1940s and 1950s, yielded to the professional spirit. Thus, while Americans had generally rejected the upper-class British social hierarchy that fostered amateurism, they retained the name amateur, continuing the hypocrisy that had begun in the previous century.