异形染色体

It was also found that the chromosomes paired well and formed a rod heteromorphic bivalent in the hybrid F1[73(36)9-1×CSDT 1BL]. Whereas 73(36)9-1 produced mainly configuration of 20''+1'+t' when test-crossed with CSDT 1BS. It showed that the translocation occurred on chromosome 1B short arm, and this segment came from rye chromosome 1RL. In the present paper we discussed also the way in which the translocation might be caused, and concluded that it was formed through reunion of two kind telocentrica (1BL and 1RL) after simultaneous misdivision of two univalent chromosomes (a wheat chromosome 1B, and a rye 1R).

同时还发现，73（36）9-1和"中国春"双端体的1BL能很好地配对并形成一个棒状的异形二价体，而它和CSDT 1BS的染色体则主要产生20+1′+t′的构型，从而证明易位发生的可能途径，推断是由于在F1花粉母细胞中的两个单价体（一个是小麦染色体1B，一个是黑麦染色体1R）同时进行错分裂之后产生的两种端着丝点染色体（1BL和1RL）重新并合形成的，因而冬小麦73（36）9-1可能是一个自发产生的易位系。

The spiny eel , belonging to Perciformes, Osteichthyes, is a kind of little freshwater fish distributed in Southern China. In 1998, Our lab detected XX/XY differentiated sex chromosomes in this specie with karyotypic analysis, and then with chromosomal binding and SC observation, we identified that its two largest metacentric chromosomes were X, Y sex chromosomes in 1999. X, Y chromosomes differ each other not only in the distribution of heterochromatin but also in their shapes, which make them could be recognized directly under the light-microscope without any banding treatment.

刺鳅，属鲈形目、刺鳅科(Perciformes，Mastacembelidae)，是广泛分布于中国南方的小型淡水鱼类。1998年，我室通过核型分析，首次发现该物种具有明显分化的异形性染色体，其性别决定类型为XX／XY型。1999年，本室通过染色体显带、精母细胞联会复合体观察，再次确认刺鳅染色体组中最大的一对中部着丝粒染色体为X、Y性染色体，两者不仅已经出现结构异染色质分布上的不同，同时在外部形态上也存在明显差异，识别特征鲜明，在光镜观察下无需显带即能清晰辨认性染色体。

F1 hybrid has the morphological feature which is between the male and female parents and shoed strong heterosis, exuberant vitality, late ripe period and low rate of self-fertility. The average chromosome configuration of F1 in PMC MI was 18.58Ⅰ+18.59Ⅱ+0.085Ⅲ+0.028Ⅳ. At anphase Ⅰ in PMC, some laggard chromosomes arranged in equatorial plate. Micronucleus and a lot of abnormal cells can be observed at dyad, tetrad and microspore.

杂种F1形态特征介于双亲之间，具有较强的杂种优势，生长旺盛，熟期晚，自交结实率较低。F1花粉母细胞减数分裂中期Ⅰ平均染色体构型为18.58Ⅰ+18.59Ⅱ+0.085Ⅲ+0.028Ⅳ，PMC后期Ⅰ观察到部分落后染色体排列在赤道板上；二分体、四分体和小孢子时期，细胞内普遍观察到微核，且出现大量异形细胞。

Among the fish which were cytogenetically studied, most of them do not possess any morphologically differentiated sex chromosomes. On the other hand, karyotypic analysis, chromosome binding, synaptonemal complex observation and comparative genomic hybridization show in few fish species, that there exist sex chromosomes which differentiated at different levels and types.

在进行过细胞遗传学研究的鱼类中，绝大部分没有发现异形性染色体，然而通过核型分析、染色体显带、联会复合体观察和比较基因组杂交等方法，发现在少部分鱼类中确实存在有异形分化的性染色体，并且分化程度高低不等，性别决定方式多种多样。

Fluorescence in situ hybridization technique was used to study the distribution patterns of 5S rDNA and 18S rDNA on chromosmoes of six species of Epinephelus.

这种同源染色体异形的现象在石斑鱼属中属首次发现。4、银染结果表明，在6种石斑鱼种内和种间，NORs数目和分布模式具有多态性。

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。