| 查看: 1674 | 回复: 4 | ||
| 【悬赏金币】回答本帖问题，作者liping515110将赠送您 120 个金币 | ||
| 本帖产生 1 个 翻译EPI ，点击这里进行查看 | ||
liping515110铜虫 (小有名气)
|
[求助]
求润色下面的英语翻译 中文是我自己写的 谢谢 不要搞反了
|
|
中文是我自己写的 求润色我翻译的英语 谢谢大家给力啊！！！！！ 尽管目前把淡水纤毛虫、水螅和海绵共生绿藻暂归类于小球藻属（genus Chlorella），但是我们对共生绿藻的物种多样性和这些藻类的宿主分布仍然是知之甚少。但是，Kessler（1984）和Reisser等（1988）的初步研究表明共生小球藻的遗传多样性可能超乎想像，但总的来说，许多类似研究皆未能阐明来源不同的共生小球藻的种间关系（Huss等1989）。Reisser等（1988）鉴定的共生小球藻Chlorella vulgaris与Huss等（1990）鉴定分析的小球藻Chlorella vulgaris的遗传实体是否一样现在不得而知。另外产自英国的绿水螅Hydra sp.的共生绿藻和产自美国佛罗里达的绿水螅Hydra sp.的共生小球藻可能为不同种的小球藻，这也可能因为二者的宿主绿水螅根本不是同种（Muscatine et al.，1975；Douglas et al.，1984）。简而言之，同一宿主的不同地理种群所共生的绿藻是否为同种、不同宿主的共生绿藻能否有可能为同种，这些问题的解答还有待于对共生绿藻起源和进化深层次的研究。 本研究尝试基于中国绿水螅及GenBank中现有的共生藻的核18S rRNA和ITS基因片段序列和小球藻属所在的Trebouxiophyceae纲的主要非共生的、自由生活的绿藻代表物种的同源序列构建分子系统发生树，期待初步探讨不同来源的共生藻与Trebouxiophyceae纲中自由生活的绿藻之间的系统发生关系，从而证实共生藻是多系起源还是单系起源。目前不同来源的共生藻核18S rRNA序列稍显丰富，所以基于共生绿藻和Trebouxiophyceae纲中自由生活的绿藻核18S rRNA序列的系统发生树（图3-2，图3-3，图3-4）给我们提供较为丰富的遗传信息。基于18S rRNA基因序列重建的ML树（图3-2）、MP树（图3-3）和Bayesian树（图3-4）均表明，参与建树的Trebouxiophyceae纲的61个种明显分离为2大分支，一个分支为共生绿藻支系，其中有水螅共生绿藻、草履虫共生绿藻、银杏共生绿藻及苔藓共生绿藻夹杂其中，而另一分支为无共生绿藻支系。这个结果表明从Trebouxiophyceae纲的大框架来看，不同来源的共生绿藻似乎有一共同起源；但从共生绿藻支系的小框架来看，不同来源的共生藻并没有排他性地聚为单系群，而在系统树中与其他自由生活的绿藻混杂排列，不同来源的共生绿藻似乎没有一共同起源。 上述从不同视角看不同来源共生绿藻的系统发生地位得到的结果好像有点自相矛盾，但如果我们能吃透问题的实质，那么这两个不同的结果实质上是统一的。Trebouxiophyceae纲的绿藻一开始应是全部为自由生活种类，这个类群的进化和演变肯定也遵循普遍的进化规律。但由于宿主（称潜在宿主最为合适）摄食、绿藻在潜在宿主体表长期外共生或绿藻与潜在宿主长期共栖等诸多特殊因素，最终导致了绿藻与宿主间的内共生关系。而内共生关系建立前绿藻和潜在宿主的密切关系是非常随机的，源于绿藻本身物种的多样性以及潜在宿主的多样性；而内共生关系一旦建立，共生绿藻和宿主间又是高度专一的，某个宿主中的共生绿藻自然转移到其他宿主的可能性为零。简言之，好比Trebouxiophyceae纲的绿藻进化路线图是一棵有根的大树，绿藻-宿主共生关系是在不同的末端树叶上发生的。也就是说，在一定意义上讲追寻绿藻-宿主共生体中的共生绿藻的起源本身就是不可能有结论的悖论、或者说是毫无意义的。本文的一些结果证实了上述假说，如即使为同一类型的宿主内共生的绿藻分类地位也大相径庭，包括中国绿水螅在内的5株来源不同的绿水螅中共生绿藻在基于18S rRNA基因序列重建的ML树（图3-2）、MP树（图3-3）和Bayesian树（图3-4）中均未聚为单系群，其中Bayesian树中5株来源不同的绿水螅中共生绿藻就有5个不同的来源。 基于18S rRNA基因序列重建的3个系统发生树从Trebouxiophyceae纲的大框架来看，为何不同来源的共生绿藻似乎有一共同起源？Trebouxiophyceae纲中共生绿藻支系和无共生绿藻支系的绿藻与潜在宿主建立内共生前的密切关系的几率应该是同等的，但最终与宿主建立共生关系的绿藻为何集中在Trebouxiophyceae纲中共生绿藻支系，最好的解释可能是共生绿藻支系的绿藻在形态或生理特性上有一定共性，而这些共性适合与宿主建立内共生关系，这还有待于对共生绿藻及共生绿藻支系中自由生活绿藻在形态及生理特性的深入研究才能作出结论。 值得注意的是，无论是基于基于18S rRNA基因序列重建的系统发生树（图3-2，图3-3，图3-4）、还是基于ITS基因序列重建的系统发生树（图3-5，图3-6，图3-7），均显示中国绿水螅共生绿藻与从美国明尼苏达州埃塔斯加湖采集的一种小球藻Meyerella planktonica有较近的亲缘关系，这对于目前把淡水纤毛虫、水螅和海绵共生绿藻都归类于小球藻属（genus Chlorella）的做法提出了挑战。中国绿水螅共生绿藻的确切定种和命名目前尚早，寄希望于对该绿藻的进一步研究。 Although the endosymbiotic green algae from freshwater ciliates, hydra or sponges were all attributed to genus Chlorella at present, we still know little about the species diversity and host distribution of them. However, the preliminary studies from Kessler(1984) and Reisser(1988) indicate that the genetic diversity of symbiotic Chlorella may be unimaginable,but in general, many similar researchs all failed to clarify the interspecies relationships of symbiotic Chlorella from different sources(Huss et al, 1989).It is still unable to find out that whether the symbiotic Chlorella vulgaris inentified by Reisser (1988) and the Chlorella valgaris identified by Huss(1990) have the same genetic entity or not. In addition,the symbiotic green algae of Hydra sp.obtained from UK and the symbiotic Chlorella of Hydra sp. produced in Florida may be two different Chlorella species,which may because that the two host hydras are not the same species at all.In brief,whether the symbiotic algae from the same host of different geographic populations are the same species or not and whether the symbiotic algae from different hots may be the same species or not, to answer these questions ,we need a futher deep research in the origin and evolution of the symbiotic algae. This study attempts to construct molecular phylogenetic trees based on the nuclear 18S rRNA and ITS gene sequences of the symbiotic algae obtained from hydra sinensis and GenBank and the homologous sequences of the representative species from non-symbiotic、free-living green algae within Chlorella genus that belongs to Class Trebouxiophyceae,looking forward to give a preliminary discussion about phylogenetic relationships between the symbiotic algae from different sources and free-living algae in Class Trebouxiophyceae,thus confirming whether the origin of symbiotic algae was polyphyletic or monophyletic.Currently, 18S rRNA sequences of symbiotic algae from difference sources are abundant, so phylogenetic trees(figure3-2,figue3-3,figue3-4) based on 18S rRNA sequences of symbiotic algae ,and free-living green algae within Class Trebouxiophyceae, provides a wealth of genetic information for us. The ML(figure3-2)、MP(figure3-3) and Bayesian trees(figure3-4) based on 18S rRNA gene sequences all indicated that 61 Species of Class Trebouxiophyceae was separated into two branches, one branch was symbiotic algae group which consist of endosymbiotic algae from hydra, paramecium, ginkgo and moss and many free-living algae, and other branch was free-living algae group which consist only of free-living algae. The result suggests that，from the perspective of Class Trebouxiophyceae broad framework, the symbiotic algae from different sources seem to have a common origin; but from the perspective of symbiotic algae group small framework, Symbiotic algae from different sources does not form a monophyletic group exclusively, but mixed with other free-living algae in phylogenetic trees, they do not seem to have a common origin.The above-mentioned results of the phylogenetic position of symbiotic algae from different sources ,which we obtained from two different perspectives, appears to be a bit contradictory, but if we can thoroughly understand the essence of the problem, we will find that the two different results are essentially uniform.The algae of Class Trebouxiophyceae should be once free-living species , and the evolution of this group must also follow the general laws of evolution. However, so many factors such as endocytosis in potential host and long-term interactions(Ectosymbiosis and Commensalism) between green algae and potential hosts, that eventually led to a endosymbiotic relationship.Because of the species diversity and the diversity of potential host, the interactions between algae and host occured randomly before the establishment of symbiotic relationship .While, once the symbiotic relationship have been established ,the relationship will be obligate,which means that one symbiotic algae corresponding to one host can not live in another when it was transferred.In brief, if we view the evolutionary roadmap of algae within Class Trebouxiophyceae as a big rooted tree, the symbiotic relationships between algae and hosts occurs on different leaves.In other words, it is meaningless to trace origin of the symbiotic algae in algae/host symbiont.Some results confirm the above hypothesis, the taxonomic status of symbiotic algae within the same type of host are also very different，In the ML、MP and Bayesian trees based on 18S rRNA gene sequences, symbiotic algae in 5 strains of green hydra(including hydra sinensis ) from different sources, are all not monophyletic, and in the Bayesian tree , the 5 strains of green hydra from different sources have 5 different origins. In the three phylogenetic trees based on 18S rRNA gene sequences, from the perspective of Class Trebouxiophyceae broad framework, why the symbiotic algae from different sources seem to have a common origin？Before a symbiotic relationship between free-living algae and potential host was established, the probability of potential host establishing a close relationship with free-living algae from symbiotic algae group should be equal to that of potential host establishing a close relationship with free-living algae from free-living algae group. However, it is worth noting that there are symbiotic algae only in symbiotic algae group but not in free-living algae group, and the best explanation may be that green algae from symbiotic green algae group have some common morphological and physiological characteristics which are beneficial to establishing of symbiotic relationship between them with host, while green algae from free-living algae group have not，but to draw a conclusion ,we should make an in-depth study in the morphology and physiological characteristics of symbiotic algae and the free-living algae within the symbiotic green algae group. It is important to note that,whether the phylogenetic trees reconstructed on the base of 18S rRNA gene sequences or the trees based on ITS gene sequences, have all shown a close genetic relationspip between hydra sinensis and Meyerella planktonica,which were collected from lake Itasca,Minnesota,USA, and this is a challenge for placing the symbiotic algae from freshwater ciliates ,hydra and sponges in genus Chlorella.That is to say, it is too early to definite and name the species of the symbiotic algae of hydra sinesis. |
回复此楼» 猜你喜欢
2026年的国家社科基金项目通讯评审的新规则与新动向、新挑战
已经有10人回复
-
有多少人是今天查系统知道结果的？
已经有16人回复
-
我不理解！
已经有14人回复
-
国自然面上复盘~欢迎讨论
已经有4人回复
-
系统查不到
已经有10人回复
-
基金不中，共勉
已经有3人回复
-
怎么查啊
已经有5人回复
-
范进中举一文的中心思想
已经有10人回复
-
2026国自然函评费到账
已经有25人回复
-
2026年8月25日国自然放榜前突然收到列入评审专家邮件，有关系吗？
已经有28人回复
8814402
至尊木虫 (职业作家)
- 翻译EPI: 509
- 应助: 18 (小学生)
- 贵宾: 0.381
- 金币: 12921.1
- 散金: 47
- 红花: 16
- 帖子: 4185
- 在线: 357.9小时
- 虫号: 1184404
- 注册: 2011-01-06
- 专业: 药物学其他科学问题
【答案】应助回帖
★ ★
sltmac(金币+2): 辛苦 2011-08-15 18:04:44
sltmac(金币+2): 辛苦 2011-08-15 18:04:44
| Although the endosymbiotic green algae from freshwater ciliates, hydra or sponges were all attributed to genus Chlorella at present, we still know little about the species diversity and host distribution of them. However, the preliminary studies from Kessler(1984) and Reisser(1988) indicated that the genetic diversity of symbiotic Chlorella may be unimaginable, but in general, many similar researchs all failed to clarify the interspecies relationships of symbiotic Chlorella from different sources(Huss et al, 1989). It is still unknown whether the symbiotic Chlorella vulgaris inentified by Reisser (1988) and the Chlorella valgaris identified by Huss(1990) have the same genetic entity or not. In addition, the symbiotic green algae from Hydra sp.obtained from UK and the symbiotic Chlorella from Hydra sp. produced in Florida may be two different Chlorella species, which may because the two host hydras are not the same species at all（Muscatine et al.，1975；Douglas et al.，1984）. In brief, we need a futher deep research in the origin and evolution of the symbiotic algae to determine whether the symbiotic algae from the same host of different geographic populations is the same species or not and whether the symbiotic algae from different hots may be the same species or not. |
2楼2011-08-15 15:52:09
8814402
至尊木虫 (职业作家)
- 翻译EPI: 509
- 应助: 18 (小学生)
- 贵宾: 0.381
- 金币: 12921.1
- 散金: 47
- 红花: 16
- 帖子: 4185
- 在线: 357.9小时
- 虫号: 1184404
- 注册: 2011-01-06
- 专业: 药物学其他科学问题
【答案】应助回帖
★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ...
sltmac(金币+50): 2011-08-23 14:45:08
sltmac(金币+50): 2011-08-23 14:45:12
sltmac(金币+20, 翻译EPI+1): 2011-08-23 14:45:18
sltmac: 帮你要过来了~~ 2011-08-23 14:45:34
sltmac(金币+50): 2011-08-23 14:45:08
sltmac(金币+50): 2011-08-23 14:45:12
sltmac(金币+20, 翻译EPI+1): 2011-08-23 14:45:18
sltmac: 帮你要过来了~~ 2011-08-23 14:45:34
| In this study, we attempt to construct molecular phylogenetic trees based on the nuclear 18S rRNA and ITS gene sequences of the symbiotic algae obtained from hydra sinensis and GenBank and the homologous sequences of the representative species from non-symbiotic, free-living green algae within Chlorella genus that belongs to Class Trebouxiophyceae, preliminarily discussing phylogenetic relationships between the symbiotic algae from different sources and free-living algae in Class Trebouxiophyceae, thus confirming whether the origin of symbiotic algae was polyphyletic or monophyletic. Currently, 18S rRNA sequences of symbiotic algae from difference sources seem abundant, so phylogenetic trees(figure3-2,figue3-3,figue3-4) based on 18S rRNA sequences of symbiotic algae and free-living green algae within Class Trebouxiophyceae provides a wealth of genetic information for us. The ML(figure3-2)、MP(figure3-3) and Bayesian trees(figure3-4) based on 18S rRNA gene sequences all indicated that 61 Species of Class Trebouxiophyceae related to trees construction were separated into two branches, one branch was symbiotic algae group which consist of endosymbiotic algae from hydra, paramecium, ginkgo and moss and many free-living algae, and the other branch was free-living algae group which consist only of free-living algae. The result suggests that，from the perspective of Class Trebouxiophyceae broad framework, the symbiotic algae from different sources seem to have a common origin; but from the perspective of symbiotic algae group small framework, Symbiotic algae from different sources do not form a monophyletic group exclusively, but mix with other free-living algae in phylogenetic trees and do not seem to have a common origin. |
3楼2011-08-15 16:10:45
8814402
至尊木虫 (职业作家)
- 翻译EPI: 509
- 应助: 18 (小学生)
- 贵宾: 0.381
- 金币: 12921.1
- 散金: 47
- 红花: 16
- 帖子: 4185
- 在线: 357.9小时
- 虫号: 1184404
- 注册: 2011-01-06
- 专业: 药物学其他科学问题
【答案】应助回帖
| The above-mentioned results of the phylogenetic position of symbiotic algae from different sources ,which was obtained by us from two different perspectives, seems a bit contradictory. But it can be seen that the two different results are essentially uniform if we can thoroughly understand the essence of the problem. The algae of Class Trebouxiophyceae should be ever free-living species, and the evolution of this group must also follow the general laws of evolution. However, many factors such as endocytosis in potential host and long-term interactions (ectosymbiosis and commensalism) between green algae and potential hosts can eventually result in a endosymbiotic relationship. Because of the species diversity and the diversity of potential host, the interactions between algae and potential hosts took place randomly before establishment of the symbiotic relationship. While, once the symbiotic relationship have been established, the relationship will be obligate, which means that one symbiotic algae corresponding to one host can not live in another host. In brief, if we view the evolutionary roadmap of algae within Class Trebouxiophyceae as a big rooted tree, the symbiotic relationships between algae and hosts only occur on different terminal tree branches. In other words, it is meaningless to trace origin of the symbiotic algae in algae/host symbiont. The above hypothesis can be confirmed some results among which the taxonomic status of symbiotic algae within the same type of host varied also. For example, in the ML, MP and Bayesian trees based on 18S rRNA gene sequences, symbiotic algae in 5 strains of green hydra including hydra sinensis from different sources are all not monophyletic, and in the Bayesian tree, the 5 strains of green hydra from different sources have 5 different origins. |
4楼2011-08-15 16:35:16
8814402
至尊木虫 (职业作家)
- 翻译EPI: 509
- 应助: 18 (小学生)
- 贵宾: 0.381
- 金币: 12921.1
- 散金: 47
- 红花: 16
- 帖子: 4185
- 在线: 357.9小时
- 虫号: 1184404
- 注册: 2011-01-06
- 专业: 药物学其他科学问题
【答案】应助回帖
|
In the three phylogenetic trees based on 18S rRNA gene sequences, from the perspective of Class Trebouxiophyceae broad framework, why the symbiotic algae from different sources seem to have a common origin？Before a symbiotic relationship between free-living algae and potential host was established, the probability of potential host establishing a close relationship with free-living algae from symbiotic algae group should be equal to that from free-living algae group. However, it is worthy noting that symbiotic algae were only found in symbiotic algae group but not in free-living algae group, and the best explanation may be that green algae from symbiotic green algae group have some common and special morphological and physiological characteristics beneficial to establishment of symbiotic relationship between them with hosts. It is needed to make in-depth studies in the morphology and physiological characteristics of symbiotic algae and the free-living algae within the symbiotic green algae group before a conclusion is made safely. It is important to note that the phylogenetic trees based on the base of 18S rRNA gene sequences and the trees based on ITS gene sequences have both shown a close genetic relationspip between hydra sinensis and Meyerella planktonica obtained from lake Itasca, Minnesota, USA. This is a challenge to the practice placing the symbiotic algae from freshwater ciliates, hydra and sponges all in genus Chlorella.That is to say, futher studies on the symbiotic algae from hydra sinesis is needed to definite and name their the species. |
5楼2011-08-15 16:57:17
投票:
