Study of the genomic constitution of the German mirror carp

Abstract

Semen was treated with ultraviolet irradiation to genetically inactivate the sperm. Gynogenetic haploidy was induced artificially in the German mirror carp, Cyprinus carpio L. A systematic study of the status of early embryonic development, the number of chromosomes, chromosomal banding patterns and fluorescent in situ hybridization (FISH), and a microsatellite analysis were performed. The fertility, hatchability, and survival rates of the gynogenetic group were significantly lower than those of the normal control fertilization group (P < 0.05). Gynogenetic larval growth was abnormal and the embryos did not survive. The chromosome number of the gynogenetic group was 50, whereas that of the control group was 100. The gynogenetic group had a single silver-staining point, one CMA3/DA/DAPI-positive position, and a single FISH-positive signal, whereas the control group had two silver-staining points, two CMA3/DA/DAPI-staining positions, and two FISH-positive signals. The microsatellite analysis showed that all the genes of the gynogenetic group derived from the female parent and that the females generated a set of haploid (n = 50) gametes during meiosis. Using chromosome manipulation, this study confirms that the German mirror carp has two sets of chromosomes and is an evolutionary tetraploid (2n = 100).