Production of pure line in fish.

为了获得雌雄性二倍体的纯种鱼种，对泥鳅配子遗传失活和抑制第一次卵裂进行染色体复制的最佳条件进行了研究。分析染色体扩散以确定胚期或苗期早期的倍性水平。用紫外线照射的精子，在授精后30-35 min施加压力冲击，持续60秒，800kg/cm^2，获得雌性二倍体，高于其他条件。通过对基因-着丝粒重组率高的位点进行基因型分析，确定了该鱼的完全纯合性。将受精卵经紫外线照射后与正常精子受精，并在与雌核发生相同的条件下进行压力冲击，获得雄激素二倍体。雌鱼和雄激素鱼的存活率很低。非整倍性包括一些片段和单倍体在许多雌胚和雄激素胚胎中被发现。这一事实可能是导致低存活率的一个因素。

In order to obtain pure line of fish by producing gynogenetic and androgenetic diploids, optimum conditions for genetic inactivation of gametes and for chromosome duplication by suppression of the first cleavage were studied in the loach, Misgurnus anguillicaudatus. Chromosome spreads were analyzed to determine ploidy level at embryonic or early fry stages.Gynogenetic diploids were obtained by pressure shocks applied 30-35 min after insemination with UV irradiated spermatozoa and lasting 60 sec, 800kg/cm^2, more than another conditions. Complete homozygosity of the fish was determined by genotypes on the locus with high rate of gene-centromere recombination. Androgenetic diploids were obtained from the eggs irradiated with UV and inseminated with normal spermatozoa, and them pressure-shocked with the same condition as in the case of gynogenesis. Survivals of gyno- and androgenetic fish was very low. Aneuploidy involving some fragments and haploidy were found in many gyno- and androgenetic embryos. This fact may be a factor responsible for low survival.