论文部分内容阅读
大量的日本泥鳅是具有５０条染色体的二倍体，但是天然产生的四倍体和三倍体却经常从泥鳅商收集来的鱼样中被发现。为了评价天然产生四倍体的程度，我们应用成熟的四倍体鱼进行实验杂交，并对染色体组做了处理，然后通过计算染色体数和测量红细胞大小来检查每一实验杂交组鱼的信性情况。在四倍体雌鱼（４ｎ♀）和四倍雄鱼（４ｎ♂）之间的杂交（４ｎ×４ｎ）以及四倍体雌鱼（４ｎ♀）和二倍体雄鱼（２ｎ♂）之间的杂交（４ｎ×２ｎ）分别产生了能存活的四倍体鱼（４ｎ＝１００ｎ）和三倍体鱼（３ｎ＝７５）子代。４ｎ×２ｎ杂交组鱼经过热刺激之后长成的鱼表现出五倍体核型（５ｎ＝１２５）。二倍体雌鱼和四倍雄鱼交配的受精卵在热刺激之后发育长成的鱼具有四倍体核型（４ｎ＝１００）。四倍体雌鱼用正常二倍体泥鳅或观赏鲤鱼（Ｃｙｐｒｉｎｕｓｃａｒｐｉｏｎ）的经过紫外线照射过的精子授精后得到雌核发育的子代。从这两组雌核发育的杂交得到的幼鱼具有源于母体的二倍体核型（２ｎ＝５０）。
Large numbers of Japanese loach are diploid with 50 chromosomes, but naturally produced tetraploids and triploids are often found in fish samples collected by loach traders. In order to evaluate the degree of tetraploid naturally occurring, we used a well-established tetraploid fish for experimental hybridization and processed the genome and then examined the letterworthiness of each experimental group of fish by counting the number of chromosomes and measuring the size of the erythrocytes Happening. (4n × 4n) and tetraploid female (4n♀) and diploid male (2n♂) between tetraploid female (4n♀) and quadrupled male (4n♂) (4n × 2n) produced viable tetraploids (4n = 100n) and triploid fish (3n = 75), respectively. The fish that grew after the 4n × 2n hybrids were heat stimulated showed pentaploid karyotype (5n = 125). The diploid female and quadrupled male mating fertilized eggs developed tetraploid karyotype (4n = 100) after thermal stimulation. Tetraploid females were progeny of gynogenetic insects after they were fertilized with normal diploid loach or UV-irradiated sperm of Cyprinus carpion. The juvenile fish obtained from the hybridization of the two sets of gynogenetic motifs have a diploid karyotype derived from the mother (2n = 50).