脊尾白虾染色体制备及核型的初步研究

The chromosome preparation and karyotype in ridgetail white prawn Exopalaemon carinicauda

以脊尾白虾Exopalaemon carinicauda原肠胚时期受精卵为材料,采用低渗法和热滴片法制备染色体,对脊尾白虾进行细胞遗传学研究。核型分析结果显示,对50尾脊尾白虾雌虾受精卵中100个良好的中期分裂相进行染色体计数,染色体数目为90的出现频率最高,达到了81%,由此确定脊尾白虾二倍体染色体数目为90,即2n=90;通过对中期分裂相染色体臂长进行测量与分析发现,中部着丝粒染色体(m)共计56条,亚中部着丝粒染色体(sm)共计8条,亚端部着丝粒染色体(st)共计12条,端部着丝粒染色体(t)共计14条,核型组成公式为2n=56m+8sm+12st+14t,没有发现异性性染色体的存在。

The cytogenetic study was conducted in ridgetail white prawn Exopalaemon carinicauda by preparation of chromosome spreads from some embryo cells at gastrula stage using hot film drops.The microphotography showed that there were 90 chromosomes in diploid（2n=90） based on the maximal frequency of 90 in chromosome number,that is,accounting for 81% in 100 metaphase chromosomes.The karyotype formula was found to be expressed as 2n=56m＋8sm＋12st＋14t in the prawn.There were 28 pairs of metacentric chromosomes（m）,4 pairs of submetacentric chromosomes（sm）,6 pairs of acroentric chromosomes（st） and 7 pairs of telocentric chromosomes（t）,and no sex-chromosome of heteromorphism was observed in the complements.