哈尔滨翻译公司，哈尔滨翻译，兴文翻译公司

原稿

挪威虹鳟和丹麦虹鳟的LDH为四聚体同工酶，由（LDH-1，2，3）三个基因座位编码。两种鱼的五种组织中都有由LDH-2和LDH-3编码的A4和B4两种四聚体同工酶表达，但无杂交四聚体带型出现。各组织间没有同工酶种类上的差异，其组织特异性只表现在含量上(图5)：挪威虹鳟心脏中LDH含量最高，丹麦虹鳟心脏和肌肉中LDH含量最高，说明组织在缺氧条件下代谢能力强。挪威虹鳟和丹麦虹鳟在肌肉中A4同工酶比B4同工酶含量高，这样在肌肉运动时消耗大量能量，促使丙酮酸转变成乳酸，满足缺氧条件下的活动。挪威虹鳟LDH-1位点所编码的同工酶只特异性在眼中表达（E4），E4只在成体细胞中出现，在多数硬骨鱼类的视网膜和脑中神经细胞中都存在E4，这种LDH同工酶的基因也称为“E基因”[8]，现在一般认为E基因是由B基因重复产生的，因而E亚基和B亚基易形成杂聚体，据此推测E4上面的酶带为杂合带，并不代表等位基因。丹麦虹鳟没有LDH-1位点。另外在图谱中还发现挪威虹鳟肌肉中也有LDH-1位点所编码的同工酶带，这在以前有关硬骨鱼乳酸脱氢酶的报道中还没有出现过，推测挪威虹鳟肌肉在缺氧条件下代谢能力强。

2.1.6 乙醇脱氢酶（ADH ， E. C. 1. 1. 1. 1）
挪威虹鳟和丹麦虹鳟的ADH为二聚体同工酶，由（ADH-1，2）两个基因座位编码。ADH-1有多态性，在五种组织中都有表达。ADH-2为单态，编码一条同二聚体酶，组织特异性明显，仅在肝脏和肾脏中表达，其中肝脏中活性最强。(图6)肝脏作为主要的内脏器官之一，具有消化、分泌以及解毒等多种功能，ADH的生理作用是适应厌氧酵解的需要，说明肝脏在缺氧条件下维持正常生理功能的能力比其它四种组织强。

2.2 挪威虹鳟和丹麦虹鳟的群体遗传多样性

2.2.1 挪威虹鳟的群体遗传多样性
以挪威虹鳟的肝脏组织作为POD同工酶遗传多样性研究材料。由图7分析可见，挪威虹鳟的POD同工酶有两个基因座位编码，均为多态，共四个等位基因。挪威虹鳟个体间的POD同工酶谱没有表现出明显的差异。
通过对挪威虹鳟的5种同工酶进行种群遗传学研究，共记录12个基因座位，其中有3个基因座位为多态，等位基因总数为15个。（表1）
多态座位的百分数P= 3 /12 × 100% =25% ，位点有效等位基因数Ne =15/12=1.25。
平均杂合度H= ∑（1- ∑X 2i）/n=0.68/12=0.0567

译稿

Lactate dehydrogenase decoded by LDH-1, 2, 3 genes in Norwegian Oncorhynchus mykiss and Danish Oncorhynchus mykiss were tetrameric isozyme. The tetrameric isozymes A4 and B4 decoded by LDH-2 and LDH-3 respectively were detected in all five kinds of tissues in both fishes without evidence of hetertetramer. There was no difference in the isozyme types among all the tissues, while the tissue-specificity only showed difference on isozyme contents (Figure 5): the contents of LDH were the highest in the hearts of Norwegian Oncorhynchus mykiss and the contents of LDH were the highest in the muscles and hearts of Danish Oncorhynchus mykiss. It suggested that the metabolism woulud be higher in anaerobic environments. The A4 isozyme in Norwegian Oncorhynchus mykiss showed a higher concentration than that of B4 isozyme in Danish Oncorhynchus mykiss. As a result, when a large amount of energy was required for muscle exercises in an anaerobic environment, pyruvic acid will be transformed into lactic acid to provide extra energy LDH-1 in Norwegian Oncorhynchus mykiss decoded isozyme (E4) and was specifically expressed in eyes. E4 only existed in adult-cells and there were E4 in almost all the nerve cells in retinas and hearts of sclerotic fishes, thus the gene decoding LDH isozyme was also called “ E gene” [8]. The present theories believed that E gene was generated from the replication of B gene, thus it was easier for E subunit and B subunit to produce heterdimer. It then can be derived that the enzymatic bands on E4 were heterogeneous, but could not prove the existence of allele. There was no LDH-1 locus in Danish Oncorhynchus mykiss. In addition, isozymes bands coded by LDH-1 locus were found in the muscles of Norwegian Oncorhynchus mykiss with the gel image. This is the first time for this observation reported on lactate dehydrogenase in sclerotic fishes. It also suggested that Norwegian Oncorhynchus mykiss had high metabolic behaviors in an anaerobic environment.

2.1.6 Alcohol Dehydrogenase (ADH, E. C. 1. 1. 1. 1)
Alcohol dehydrogenase decoded by ADH-1, 2 genes in Norwegian Oncorhynchus mykiss and Danish Oncorhynchus mykiss were dimeric isozyme. ADH-1 was polymorphous and expressed in five kinds of tissues. ADH-2 was monomorphous and decoded homodimer enzyme with high tissue-specificity, which was only expressed in livers and kidneys and had highest activities in livers. (Figure 6) As a major organ, liver’s functions include digestion, secretion and detoxification. The physiological functions of ADH fitted for the needs in anaerobic fermentation, which demonstrated that it was easier for liver to keep normal physiological functions than the other four kinds of tissues in an anaerobic environment.

2.2 Diversity of Population Genetics in Norwegian Oncorhynchus mykiss and Danish Oncorhynchus mykiss

2.2.1 Diversity of Population Genetics in Norwegian Oncorhynchus mykiss
We selected liver tissue obtained from Norwegian Oncorhynchus mykiss as samples in the study of the genetic diversity of POD isozyme. It can be seen from Figure 7 that POD isozyme in Norwegian Oncorhynchus mykiss was decoded by two gene loci. Both of the two genes are polymorphous, and there are totally four alleles. There was no significant difference on the POD isozymeric images among individual Norwegian Oncorhynchus mykiss.
Total twelve gene loci had been studied through population genetics for five kinds of isozymes in Norwegian Oncorhynchus mykiss. Among them, there are three polymorphous gene loci and totally 15 alleles. (Table 1)
The percent of polymorphous gene loci P= 3 /12 × 100% =25%,
Number of alleles with effective locations Ne =15/12=1.25
Average of heterogeneity: H= ∑（1- ∑X 2i）/n=0.68/12=0.0567