CAJ | 학술논문

为了解中国宽额鳢的遗传背景以更好地保护和开发利用资源,测定了云南澜沧江和海南岛南渡江、万泉河与昌化江等4个水系9个群体74尾宽额鳢线粒体控制区411 bp序列,发现52个变异位点和20个单倍型；在系统树上可分为云南、海南毛阳群体和海南其他群体等3个分支。谱系间Fst为0.786—0.672(P<0.01),基因流Nm为0.153—0.244；74.352%的变异来自谱系间,谱系间分化时间为2.070—0.350 Ma。推测海南与云南宽额鳢分化可能受云贵高原隆起和海南岛与陆地分离等地质事件影响；海南2个谱系的形成则可能是受到了五指山山脉隆起的影响。云南组群与海南组群间Fst为0.765(P<0.01),基因流Nm为0.149,70.360%的变异来自不同地理组群间,表明云南组群和海南组群间高度分化。相比同区域分布的鱼类,宽额鳢总体的单倍型多样性和核苷酸多样性均较高(Hd=0.903±0.016,π=0.036±0.003),其中海南琼中和石壁群体的核苷酸多样性(π)最高均为0.008；云南勐腊群体最低为0.000；但各个地理群体均比总体的遗传多样性低,可能是后者由多个谱系叠加所致。在简约性网络图中单倍型呈非典型星状分布,中性检验为非显著负值和核苷酸不配对分析呈现多峰分布,表明宽额鳢群体历史上较为稳定,没有出现显著种群扩张。
위료해중국관액례적유전배경이경호지보호화개발이용자원,측정료운남란창강화해남도남도강、만천하여창화강등4개수계9개군체74미관액례선립체공제구411 bp서렬,발현52개변이위점화20개단배형；재계통수상가분위운남、해남모양군체화해남기타군체등3개분지。보계간Fst위0.786—0.672(P<0.01),기인류Nm위0.153—0.244；74.352%적변이래자보계간,보계간분화시간위2.070—0.350 Ma。추측해남여운남관액례분화가능수운귀고원륭기화해남도여륙지분리등지질사건영향；해남2개보계적형성칙가능시수도료오지산산맥륭기적영향。운남조군여해남조군간Fst위0.765(P<0.01),기인류Nm위0.149,70.360%적변이래자불동지리조군간,표명운남조군화해남조군간고도분화。상비동구역분포적어류,관액례총체적단배형다양성화핵감산다양성균교고(Hd=0.903±0.016,π=0.036±0.003),기중해남경중화석벽군체적핵감산다양성(π)최고균위0.008；운남맹석군체최저위0.000；단각개지리군체균비총체적유전다양성저,가능시후자유다개보계첩가소치。재간약성망락도중단배형정비전형성상분포,중성검험위비현저부치화핵감산불배대분석정현다봉분포,표명관액례군체역사상교위은정,몰유출현현저충군확장。
Channa gachus is a tropical and subtropical species of freshwater carnivorous fish, and they have highly or-namental and economic values in original origins.C. gachus usually live in slow-flow rivers, ditches and ponds.As for in China, they mainly inhabit in the Irrawaddy River, the Nujiang River and the Lancang River in Yunnan Province, as well as in some rivers in Hainan Province. Due to the extensive hydraulic construction, river pollution and overfishing, the number of the fish has sharply decreased. To develop effective strategies of protecting its germplasm, it is important to investigate the genetic variance and the structure of the population of this species. Previous studies have focused on the chromosome and the isoenzyme of C. gachus, as well as the phylogenetic relationship betweenC. gachusand other species in the same genus.However, the genetic backgound of this fish remains obsecure. In the present study, we sequenced 411 bp segments of mitochondrial DNA control regions of 74C. gachusindi-viduals collected from 9 populations in the Lancang River in Yunnan Province, and the Nandu River, the Wanquan River and the Changhua River in Hainan Province of China. We observed 52 mutations of nucleotide acids and 20 haplotypes. There were 3 haplotypes shared by 5 populations in Hainan Province, whereas all other haplotypes were unique in each population. We observed 3 distinct lineages in the Kimura2-parameter-based Neighbour-Joining tree. One of them was from Yunnan, and the other 2 were from Hainan—one was the Maoyang population from the Changhua River, another was from the Nandu River and the Wanquan River, and the rest two populations were from the Changhua River. The pairwise fixation indexFstwas 0.786—0.672, the gene flow was 0.153—0.244, and the inter-clade variation accounted for 74.352% of the total variation. These data indicated a significant genetic differentiation between the 3 clades. The differentiation time of the 3 clades was 2.070—0.350 Ma. The differentiation of the Hainan and Yunnan groups might have been affected by the uplift of Yunnan-Guizhou Plateau and the separation of Hainan Island from Mainland China. Following the isolation from the Maoyang population, the 2 distinct lineages in Hainan Island might be formed under the impact of the uplift of Wuzhi Mountains. Parameters such as theFst (0.765,P<0.01), the gene flow (0.149) and the genetic variation (70.360%) between the Yunnan and Hainan groups indicated a high degree of differentiation. In con-trast to the high overall genetic diversity (Hd=0.903±0.016,π=0.036±0.003), the nucleotide diversity within individual populations was much lower. The nucleotide diversity of the Qiongzhong and Shibi populations was the highest (0.008), and the Mengla population had the lowest diversity (0.000). The high overall genetic diversity might result from a mix-ture of multiple lineages. In the parsimony network ofC. gachus, the haplotypes from Yunnan Province were on one side, and the haplotypes from the Maoyan population were in the middle, and the remaining from Hainan Island were on the other side. The distribution of the haplotypes showed an atypical star-shape in the parsimony network diagram. The neutrality tests gave a non-significant negative value. Moreover, the mismatch distribution analysis displayed a multimodal distribution. These results suggested that there was no significant expansion in the population in recent history. Because there are 3 lineages of ChineseC. gachus, we recommended that they should be treated as 3 separate protected units.