MEIOTIC DRIVE FOR B-CHROMOSOMES IN PRIMARY OOCYTES OF MYRMELEOTETTIX-MACULATUS (ORTHOPTERA-ACRIDIDAE)
MEIOTIC DRIVE FOR B-CHROMOSOMES IN PRIMARY OOCYTES OF MYRMELEOTETTIX-MACULATUS (ORTHOPTERA-ACRIDIDAE)
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DOI：
10.1007/bf00292957
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发表时间：
1976-01-01
期刊：
影响因子：
1.6
通讯作者：
HEWITT, GM
中科院分区：
文献类型：
--
作者：
HEWITT, GM
利用一种改进的技术，可以观察到蝗虫后期开始时原始卵母细胞的染色体取向，b染色体优先分布在中期板的卵侧而不是极体侧。这种优先定向的频率与从同一种群中使用个体的育种实验确定的优先传播水平相匹配。纺锤体在该物种的原代卵母细胞中是不对称的，并提出了一种可能的解释，即核质在纺锤体周围呈锥形。这些女性的常染色体交叉频率通常低于可比男性，并且由于B染色体的存在而增加；但两性的交叉频率对1条和2条b染色体的增加有不同的反应。
Using a modified technique which allowed observation of chromosome orientation in the primary oocyte of grasshoppers at the onset of anaphase, the B-chromosome is distributed preferentially on the egg side of the metaphase plate rather than the polar body side. The frequency of this preferential orientation matches the level of preferential transmission determined from breeding experiments using individuals from the same population. The spindle is asymmetrical in the primary oocyte of this species, and a possible explanation of the meiotic drive is proposed as a result of the conical shape of nucleoplasm surrounding this spindle. The autosomal chiasma frequency of these females is generally lower than comparable males and is increased by the presence of B chromosomes; but the chiasma frequencies of the sexes respond differently to the addition of 1 and 2 B-chromosomes.