Spontaneous mosaicism occurred in normally fertilized and gynogenetically induced progeny of the kokanee salmon Oncorhynchus nerka     

MINORU  TANAKA  SHIZUO  KIMURA  TAKAFUMI  FUJIMOTO  SUZU  SAKAO  ETSURO  YAMAHA  KATSUTOSHI  ARAI 《Fisheries Science》2003,69(1):176-180

ABSTRACT:   In normally fertilized progeny of the kokanee salmon Oncorhynchus nerka , DNA content flow cytometry revealed that all the externally normal embryos were diploid, whereas abnormal embryos exhibited haplo-diploid, diplo-tetraploid and haplo-diplo-tetraploid mosaicisms, together with a few haploid and diploid individuals. When gynogenetic development was artificially induced by fertilization of eggs obtained from a female of the same kokanee brood stock with UV-irradiated sperm, haplo-diploid mosaics appeared most frequently. These mosaics were likely to happen by certain cytological events, such as meiotic or mitotic errors during the process of maturation, fertilization or early cleavage.  相似文献   

Dorso-ventral axis perturbation in goldfish embryos caused by heat- and pressure-shock treatments for chromosome set manipulation     

ETSURO  YAMAHA  SATOSHI  OTANI  ATSUYOSHI  MINAMI  KATSUTOSHI  ARAI 《Fisheries Science》2002,68(2):313-319

ABSTRACT: Effects of the chromosome set manipulation on early embryonic development were examined in goldfish and crucian carp. Both pressure- and heat-shock treatments of fertilized eggs induced developmental disorders such as thin blastodisc formation, delay of epiboly, and deficiency of dorso-anterior structures. The longer the treatments were applied to the eggs, the more frequently severe dorsal deficiencies were induced in the embryos. No and reduced signals of goosecoid mRNA, a dorsal mesodermal marker, were observed in embryos treated with heat-shock at 40°C for 1 min at 5 min postfertilization. These results suggested that such treatments should affect not only the retention of the second polar body, but also the suppression of dorso-ventral differentiation.  相似文献