Abstract

All-female diploid Paralichtlrys olivaceus populations were produced by the artificial fertilization with the normal eggs and gynogenetic diploid males sperms. All-female triploids were also conducted to the fertilized eggs by cold shock. Floating, fertilization and hatching rates of the all-female diploid eggs were not significantly different from that of the diploid control eggs (P>0.05). All-female triploids were also not significantly different from their diploid controls or all-female diploid groups (P>0.05) in the floating and fertilization rates of eggs. However, hatching rates of all-female triploid groups were lower than that of the control (P<0.05). Induction of the triploids were confirmed by the measurement of erythrocyte sizes and by the chromosome counts. The volumes of erythrocytes and nucleus of triploid were larger than those of diploids, respectively. Percent incidences of triploid were $92.6\%$ in this experiment. The chromosome number of diploids and triploids showed 2n=48 and 3n=72, respectively, and their karyotypes were consisted of all acrocentric chromosomes. The gonads of 4-month-old triploids were histologically sterile.

넙치 암컷과 유도된 자성발생성 2배체 숫컷 넙치를 교배시켜 넙치의 전 암컷 2배체를 생산한 후, 전 암컷 수정난에 저온처리하여 전 암컷 3배체 넙치를 생산하였다. 그 결과 부상율 및 수정율에 있어서 2배체 대조군, 전 암컷 2배체, 3배체 대조군 그리고 전 암컷 ,3배체군 모두에서 차이가 없었다 (P>0.05). 그러나, 3배체 대조군 및 전 암컷 3배체군은 여타 실험군에 비해 부화율이 낮게 나타났다 (P<0.05). 생식소의 조직학적 분석 결과 전 암컷 2배체 처리군 및 전 암컷 3배체 처리군의 성비는 모두 $100\%$ 암컷이었다. 배수체 검정을 위해 세포크기 및 염색체를 분석한 결과, 세포 및 핵의크기는 3배체가 대조군에 비해 각각 1.95 및 1.96 배 증가되었고, 염색체 수 및 핵형은 2n=48 및 3n=72 acrocentric chromosome이었다. 생식소의 조직학적 분석 결과, 4개월 된 3배체 암컷의 생식소는 전형적인 생식소 수준의 불임을 보여 주었다.

Keywords