Differential fertilisation compatibility in Atlantic salmon: implications for farmed salmon gene introgression and hybridisation

大西洋鲑鱼的差异受精兼容性：对养殖鲑鱼基因渗入和杂交的影响

• 批准号: NE/E007279/1
• 负责人: Matthew Gage
• 金额: $ 42.15万
• 依托单位: University of East Anglia
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2007
• 资助国家: 英国
• 起止时间: 2007 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FE007279%2F1
• 关键词: Differential; fertilisation; compatibility; Atlantic; salmon

One of the most important barriers to reproduction between different species is compatibility between sperm and egg. Biologists are trying to understand the evolution of recognition and compatibility between gametes, but for most species nothing is known about how sperm and egg co-evolve to recognise one-another for fertilization. Recent research shows that this process probably evolves very quickly, probably because of sperm competition between males to fertilise the eggs, and conflict between males and females to get the most out of reproduction. We will examine the compatibility between sperm and egg in Atlantic salmon, which is an ideal model to examine these questions for both pure and applied reasons. Salmon adults return to the river where they hatched to reproduce. This strategy means that genetic mixing between different populations is low, and biologists have shown that different strains have clear genetic differences, and have evolved specific adaptations for their own population (such as size, spawning age etc). These isolating conditions make salmon a likely species to have evolved differences between populations in sperm and egg compatibility, because of those rapid evolutionary processes just mentioned. We have found evidence for differences in fertilization compatibility between salmon strains, based on quite specific, but important immunity genes. In this project we plan to examine these differences in much more breadth by looking at how sperm and egg fertilization compatibility has changed between different populations, while also applying these theories to a key problem facing wild Atlantic salmon. Wild Atlantic salmon are an important fish for many reasons, but are unfortunately in severe decline. A major problem facing wild salmon stocks is the escape of farmed salmon, which occurs over the salmon's range at a very high level. Escaped fish can survive, and some make it onto wild salmon spawning grounds. Here they attempt to spawn with wild fish, presenting a major problem: farmed salmon have been domestically-selected for big genetic differences with wild fish. Offspring from farmed and wild salmon reproduction carry inferior farmed genes, and mean that important wild genes in different populations become diluted. Continual release of so many farmed fish could eventually genetically swamp wild genes, possibly permanently losing specifically evolved local adaptations forever. One could imagine a similar situation if domestic dogs were continually released into wolf populations to breed; eventually the pure, wild wolf genes would be lost if release occurred every year at high enough rates. A vital piece of information in understanding the level of the farmed salmon problem is how fertile are crosses between farmed and wild salmon? Domestication might have altered farmed salmon fertility, either up or down. Research has shown that farmed fish can successfully reproduce with wild fish, but that they are inferior at reproduction. However, exactly HOW inferior are farmed fish, and how does this inferiority vary when reproducing with different wild populations? This information is important to understand the risk of farmed fish to wild stocks. We will answer this question by measuring the fertility of farmed sperm and eggs with wild salmon sperm and eggs. We have developed trials that run fertilisations in controlled conditions, but which mimic the normal function of sperm and egg in a salmon river. We will also examine fertilisation success when wild and farmed sperm mix and compete for a batch of eggs, a process which occurs normally in the wild. We will also measure how fertile farmed salmon are with a close relative, trout, since this is another possible way for farmed hybrids to be produced. Our research will allow us to measure the relative fertility of farmed salmon, thus providing very useful information for governments balancing wild fish conservation with commercially important salmon farming.

不同物种之间繁殖最重要的障碍之一是精子和鸡蛋之间的兼容性。生物学家正试图了解配子之间的识别和兼容性的演变，但是对于大多数物种而言，对于精子和鸡蛋如何共同识别施肥的人是一无所知。最近的研究表明，这一过程可能很快发展，这可能是由于男性之间的精子竞争以使卵受精，以及男性和女性之间的冲突，以最大程度地利用繁殖。我们将研究大西洋鲑鱼中的精子和鸡蛋之间的兼容性，这是出于纯粹和应用原因检查这些问题的理想模型。鲑鱼成年人返回河孵化以繁殖的河流。该策略意味着不同人群之间的遗传混合较低，生物学家表明，不同的菌株具有明显的遗传差异，并且已经为自己的人群（例如大小，产卵年龄等）进化了特定的适应性。由于刚刚提到的那些快速的进化过程，这些隔离条件使鲑鱼成为可能在精子和鸡蛋兼容性中发展差异的物种。我们发现了基于相当特异但重要的免疫基因的鲑鱼菌株之间受精兼容性差异的证据。在这个项目中，我们计划通过查看不同人群之间的精子和鸡蛋受精的兼容性如何改变了更多的广度上的这些差异，同时还将这些理论应用于野生大西洋鲑鱼面临的关键问题。出于许多原因，野生大西洋鲑鱼是重要的鱼类，但不幸的是严重下降。野生鲑鱼库存面临的一个主要问题是养殖鲑鱼的逃生，该鲑鱼在很高的水平上发生在鲑鱼的范围内。逃脱的鱼可以生存，有些可以将其进入野生鲑鱼产卵地。在这里，他们试图用野生鱼产卵，这是一个主要问题：养殖鲑鱼是在国内选择的，因为野生鱼的遗传差异很大。养殖和野生鲑鱼繁殖的后代具有较低的养殖基因，这意味着不同种群中的重要野生基因被稀释了。持续释放如此多的养殖鱼可能最终会淹没野生基因，可能永久失去特殊进化的局部适应。如果不断释放到狼种群中，人们可以想象类似的情况。最终，如果每年以高速释放发生释放，纯净的野狼基因将丢失。了解养殖鲑鱼问题水平的重要信息是养殖和野生鲑鱼之间的交叉如何肥沃？驯化可能改变了养殖鲑鱼的生育能力，无论是上下的。研究表明，养殖鱼可以成功地用野生鱼繁殖，但它们在繁殖时较低。但是，养殖鱼类的较低程度到底是多么劣等，在与不同的野生种群中繁殖时这种自卑是如何变化？这些信息对于了解野生鱼类的风险很重要。我们将通过用野生鲑鱼精子和鸡蛋来测量养殖精子和鸡蛋的生育能力来回答这个问题。我们已经开发了在受控条件下进行施肥的试验，但模仿了鲑鱼河中精子和鸡蛋的正常功能。当野生和养殖精子混合并竞争一批鸡蛋时，我们还将检查施肥成功，这是通常发生在野外的过程。我们还将衡量养殖鲑鱼的肥沃鲑鱼如何与亲戚，鳟鱼，因为这是生产养殖杂种的另一种可能的方法。我们的研究将使我们能够衡量养殖鲑鱼的相对生育能力，从而为在野生鱼类保护和商业上重要的鲑鱼种植平衡的政府提供非常有用的信息。

项目成果

Rapid rates of sperm DNA damage after activation in tench (Tinca tinca: Teleostei, Cyprinidae) measured using a sperm chromatin dispersion test.

使用精子染色质分散测试测量丁丁鱼（Tincatinca：Teleostei，Cyprinidae）激活后精子 DNA 快速损伤率。

• DOI: 10.1530/rep-09-0105
• 发表时间: 2009
• 期刊: Reproduction (Cambridge, England)
• 作者: López-Fernández C

Assessing risks of invasion through gamete performance: farm Atlantic salmon sperm and eggs show equivalence in function, fertility, compatibility and competitiveness to wild Atlantic salmon.

• DOI: 10.1111/eva.12148
• 发表时间: 2014-04
• 期刊: Evolutionary applications
• 影响因子: 4.1
• 作者: Yeates SE;Einum S;Fleming IA;Holt WV;Gage MJ
• 通讯作者: Gage MJ

Post-copulatory opportunities for sperm competition and cryptic female choice provide no offspring fitness benefits in externally fertilizing salmon.

• DOI: 10.1098/rsos.150709
• 发表时间: 2016-03
• 期刊: Royal Society open science
• 影响因子: 3.5
• 作者: Lumley AJ;Diamond SE;Einum S;Yeates SE;Peruffo D;Emerson BC;Gage MJ
• 通讯作者: Gage MJ

Cryptic choice of conspecific sperm controlled by the impact of ovarian fluid on sperm swimming behavior.

• DOI: 10.1111/evo.12208
• 发表时间: 2013-12
• 期刊: Evolution; international journal of organic evolution
• 作者: Yeates SE;Diamond SE;Einum S;Emerson BC;Holt WV;Gage MJ
• 通讯作者: Gage MJ