 |
 |
 |
 |
 |
 |
||
 |
 |
 |
 |
 |
| 2 | 1/1 | 返回列表 |
| 查看: 408 | 回復(fù): 1 | |||
| 本帖產(chǎn)生 1 個 翻譯EPI ，點擊這里進(jìn)行查看 | |||
靜爍新蟲 (初入文壇)
|
[交流]
求助翻譯
|
||
|
Although the impact of pollution on genetic variability has been assessed previously (Bickham et al.,2000; Belfiore and Anderson, 2001 for a review), this study is novel in several aspects. First, our study focused on the level of bioaccumulation in a species extremely prone to pollution due to its high fat content,reflecting the actual pollution stress in the organism(Collings et al., 1996). Its catadromous life historyenables the detection of local pollutant influences on somatic and genetic characteristics, as juveniles enter rivers with much less pollution load or differential genetic background than locally reproducing and genetically distinct freshwater species. Their level of bioaccumulation after a few years spent in the rivers can be considered as indicative of their fitness, because strongly polluted eels detoxify less efficiently, have a lower condition and might be less successful spawners (Feunteun, 2002). Secondly, it has been suggested that several genetic markers should be used to discriminate between the influence of selection and other factors that might be marker specific (Belfiore and Anderson, 2001). In this study we compared patterns from strictly neutral genetic markers (microsatellite DNA) with enzymatic markers (allozymes), for which the assump- tion of selective neutrality has often been challenged(Eanes, 1999). The significance of assessing biometric (weight, condition, growth) responses has also been underlined as a measure of pollutant impact on the organism(Van Straalen and Timmermans, 2002). Finally,the study of highly vagile organisms with a catadromous life-history like eel remains underrepresented,due to the difficulty of defining biologically relevant populations. Earlier studies used reproductively isolated populations, enabling straightforward population comparisons in the light of the “genetic erosion” hypothesis (Van Straalen and Timmermans, 2002). Here, we explain this issue in two ways, namely (1) by assessing the impact of pollutants on genetic variability (“Genetic Erosion” hypothesis) and (2) by considering individual genetic variability as an advantage to cope with pollution (“Heterosis” or “overdominance”hypothesis). Nevertheless, due to the catadromous lifehistory of eel and its failure to breed in captivity, no strong conclusions about evolutionary consequences can be drawn from our observations. |
回復(fù)此樓» 猜你喜歡
一志愿東華大學(xué)化學(xué)070300，求調(diào)劑
已經(jīng)有8人回復(fù)
-
277材料科學(xué)與工程080500求調(diào)劑
已經(jīng)有7人回復(fù)
-
317求調(diào)劑
已經(jīng)有18人回復(fù)
-
293求調(diào)劑
已經(jīng)有5人回復(fù)
-
280分求調(diào)劑 一志愿085802
已經(jīng)有7人回復(fù)
-
0854電子信息求調(diào)劑
已經(jīng)有3人回復(fù)
-
263求調(diào)劑
已經(jīng)有4人回復(fù)
-
石河子大學(xué)（211、雙一流）碩博研究生長期招生公告
已經(jīng)有3人回復(fù)
-
一志愿西安交通大學(xué)材料工程專業(yè) 282分求調(diào)劑
已經(jīng)有13人回復(fù)
-
北科281學(xué)碩材料求調(diào)劑
已經(jīng)有6人回復(fù)
★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★ ★
wypward(金幣+2):謝謝參與 2010-09-20 20:51:18
ringzhu(金幣+5, 翻譯EPI+1): 2010-11-22 12:46:30
ringzhu(金幣+5):辛苦了 這么一長段 不容易啊 樓主太小氣了 才給5個 姐姐再給你5個 鼓勵一下 哈哈~~~ 2010-11-22 12:47:07
wypward(金幣+2):謝謝參與 2010-09-20 20:51:18
ringzhu(金幣+5, 翻譯EPI+1): 2010-11-22 12:46:30
ringzhu(金幣+5):辛苦了 這么一長段 不容易啊 樓主太小氣了 才給5個 姐姐再給你5個 鼓勵一下 哈哈~~~ 2010-11-22 12:47:07
| 盡管目前已經(jīng)知道遺傳多樣性受污染的影響（Bickham et al.,2000; Belfiore and Anderson, 2001 for a review），在某些方面這項研究還是新的。首先，我們的研究關(guān)注的是由于高脂肪含量而極端受到污染的物種的生物量積累水平，這反映了有機(jī)體受到的實際污染壓力(Collings et al., 1996)。它們的逐漸衰弱的生活史有助于檢測出本地污染物對細(xì)胞體和遺傳特性的影響，因為幼年體與本地再生的及遺傳特性不同的淡水品種相比，進(jìn)入河中時攜帶很少的污染量和不同的遺傳學(xué)背景。在河中呆幾年時間后的生物量積累水平可以用來指示它們的健康狀況，因為受強(qiáng)烈污染的鰻魚去毒不明顯，狀態(tài)不好，可能不會成為成功的產(chǎn)卵魚(Feunteun, 2002)。其次，已經(jīng)證明幾個遺傳標(biāo)記可以用于區(qū)別選擇的影響，還有一些標(biāo)記可能是特意標(biāo)記(Belfiore and Anderson, 2001)。這個研究中，我們比較了用帶有酶學(xué)標(biāo)記（等位基因酶）的嚴(yán)格中立的遺傳標(biāo)記（微衛(wèi)星DNA）得到的品種，因為選擇中立性的假說多次被質(zhì)疑(Eanes, 1999)。得到生物測定（重量，條件，生長）相應(yīng)曲線的重要性也被強(qiáng)調(diào)為一種測定污染對有機(jī)體的影響的方法(Van Straalen and Timmermans, 2002)。最后，由于定義生物相關(guān)性群體很困難，對向鰻魚這樣高度游離的，具逐漸衰弱的生活史的有機(jī)體的研究仍然不具足夠的代表性。早期的研究用的是再生的分離群體，使得根據(jù)“遺傳侵蝕”假說比較直接得到的群體成為可能(Van Straalen and Timmermans, 2002)。這里，我們用兩種方法解釋了這個問題，一是估計污染對遺傳多樣性的影響（“遺傳侵蝕”假說），二是考慮個體遺傳多樣性應(yīng)對污染時的優(yōu)勢（“雜種優(yōu)勢”或者“超顯性”假說）。無論怎樣，由于鰻魚的逐漸衰弱的生活史和其喪失育性，我們的觀察得不出進(jìn)化結(jié)果的有力結(jié)論。 |
2樓2010-09-19 19:04:53
相關(guān)版塊跳轉(zhuǎn)
我要訂閱樓主 靜爍 的主題更新
| 2 | 1/1 | 返回列表 |
| 最具人氣熱帖推薦 [查看全部] | 作者 | 回/看 | 最后發(fā)表 | |
|---|---|---|---|---|
|
[考研] 070300化學(xué)求調(diào)劑 +3 | 苑豆豆 2026-03-20 | 3/150 |
|
|---|---|---|---|---|
|
[考研] 384求調(diào)劑 +3 | 子系博 2026-03-22 | 4/200 |
|
|
|
[考研] 生物學(xué)一志愿985，分?jǐn)?shù)349求調(diào)劑 +4 | zxts12 2026-03-21 | 7/350 |
|
|
|
[考研] 廣西大學(xué)材料導(dǎo)師推薦 +3 | 夏夏夏小正 2026-03-17 | 5/250 |
|
|
|
[考研] 0703化學(xué)調(diào)劑 +4 | 妮妮ninicgb 2026-03-21 | 4/200 |
|
|
|
[考研] 0805材料320求調(diào)劑 +3 | 深海物語 2026-03-20 | 3/150 |
|
|
|
[考研] 南昌大學(xué)材料專碩311分求調(diào)劑 +6 | 77chaselx 2026-03-20 | 6/300 |
|
|
|
[考研] 一志愿天津大學(xué)化學(xué)工藝專業(yè)（081702）315分求調(diào)劑 +12 | yangfz 2026-03-17 | 12/600 |
|
|
|
[考研] 307求調(diào)劑 +3 | wyyyqx 2026-03-17 | 3/150 |
|
|
|
[考研] 299求調(diào)劑 +6 | △小透明* 2026-03-17 | 6/300 |
|
|
|
[考研] 一志愿中國石油大學(xué)（華東） 本科齊魯工業(yè)大學(xué) +3 | 石能偉 2026-03-17 | 3/150 |
|
|
|
[考研] 一志愿華中科技大學(xué)，080502，354分求調(diào)劑 +5 | 守候夕陽CF 2026-03-18 | 5/250 |
|
|
|
[考研] 南京大學(xué)化學(xué)376求調(diào)劑 +3 | hisfailed 2026-03-19 | 6/300 |
|
|
|
[考研] 求調(diào)劑一志愿南京航空航天大學(xué)289分 +3 | @taotao 2026-03-19 | 3/150 |
|
|
|
[考研] 求調(diào)劑 +3 | @taotao 2026-03-20 | 3/150 |
|
|
|
[考研] 求調(diào)劑 +3 | eation27 2026-03-20 | 3/150 |
|
|
|
[考研] 工科材料085601 279求調(diào)劑 +7 | 困于星晨 2026-03-17 | 9/450 |
|
|
|
[考研] 材料考研調(diào)劑 +3 | xwt。 2026-03-19 | 3/150 |
|
|
|
[考研] 本科鄭州大學(xué)物理學(xué)院，一志愿華科070200學(xué)碩，346求調(diào)劑 +4 | 我不是一根蔥 2026-03-18 | 4/200 |
|
|
|
[考研] 275求調(diào)劑 +4 | 太陽花天天開心 2026-03-16 | 4/200 |
|