How Ecological and Genetic Factors Interact to Determine When Self-Fertilizing Hermaphrodites of Rivulus marmoratus Change into Functional Secondary Males, With a Reappraisal of the Modes of Intersexuality Among Fishes
How Ecological and Genetic Factors Interact to Determine When Self-Fertilizing Hermaphrodites of Rivulus marmoratus Change into Functional Secondary Males, With a Reappraisal of the Modes of Intersexuality Among Fishes
复制标题
生态和遗传因素如何相互作用来确定斑马鱼自花授粉雌雄同体何时转变为功能性次生雄性，并重新评估鱼类间性行为的模式
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发表时间：
1971
期刊：
影响因子：
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通讯作者：
R. Harrington
中科院分区：
文献类型：
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作者：
R. Harrington
在最初的3-6个月，从/4胚盘或更早（“早期饲养期”），将每个终身隔离的Rivulus marmoratus雌雄同体暴露于交替温度、盐度和光照强度的八种组合中的一种或另一种。在他们的余生中，他们被关在40%的海水中，温度接近25？除了一个人工短日季节外，暴露于自然日长。记录了它们的生活事件和它们产下的所有蛋的情况。雌雄同体变成第二个男性的相关性减少产卵，并在响应一个或另一个的四个年度，和一个人工短日季节，1961年至1965年。这种反应性的发作具有基因型特异性的年龄依赖性。在两个遗传上不同的，单亲，纯合，等基因组（克隆）的鱼，早期饲养在高温下，一个克隆的鱼变成男性在响应前两个短日照季节，那些其他在响应最后三个，没有重叠。在相同的生物型（克隆），这种反应性是先进的早期饲养在高温下，雌雄同体早期饲养在中等或低温很少变成男性，然后只有接近年底的生命延长保护条件。调度的性别变化显然是不受盐度，光照强度，或任何三种形态（非适应性修改），诱导早期暴露于昏暗的光线和形态特定的盐度-温度组合。年复一年，卵睾丸的睾丸区面积逐渐增加，超过卵巢区，明显表达了性别继承中的年龄依赖性（时间测量）因素，该因素将反应性的开始固定在短时间内。当睾丸与卵巢组织的比例变得足够大时，下一个短日照季节显然会引发睾丸组织的快速进一步增殖和卵巢组织的退化，从而结束产卵，开始次级雄性着色，并通过将卵睾丸转化为次级睾丸而将自我发育的雌雄同体转变为功能性次级雄性。睾丸活动，自受精卵的百分比测定，是低得多的整个雌雄同体阶段的鱼早在低温饲养相比，高，但卵巢活动，每单位时间产卵的数量测定，是相似的鱼早在低温和高温。随着日照长度从年度最低值的增加，睾丸活动每年都在增加。在年日照周期的后期，卵巢活动随着日照时间的延长而增加，睾丸活动则相应地受到抑制
Hermaphrodites of Rivulus marmoratus, each in lifelong isolation, were exposed to one or another of the eight combinations of alternative temperatures, salinities, and light intensities, for the first 3-6 months from /4 blastoderm or earlier ("early-rearing period"). For the rest of their lives they were kept in 40% sea water at near 25? C and exposed to natural day lengths except for one artificial short-day season. Their life episodes and the conditions of all the eggs they laid were recorded. Hermaphrodites changed into secondary males in correlation with diminished egg laying and in response to one or another of the four annual, and one artificial short-day seasons, 1961-1965. Onset of this responsivity has a genotype-specific age-dependency. In two genetically unlike, uniparental, homozygous, isogenic groups (clones) of fish, early-reared at high temperature, the fish of one clone changed into males in response to the first two short-day seasons, those of the other in response to the last three, with no overlap. Within the same biotype (clone), this responsivity is advanced calendrically by early-rearing at high temperature; hermaphrodites early-reared at moderate or low temperature very rarely change into males and then only near the ends of lives prolonged by protected conditions. Scheduling of the sex changes was apparently unaffected by salinity, light intensity, or any of three morphoses (nonadaptive modifications), induced by early exposure to dim light and morphosis-specific salinity-temperature combinations. From year to year, the testicular zones of the ovotestes progressively increase in area more than the ovarian zones, expressing visibly the agedependent (time-measuring) factor in sex succession that fixes the onset of of the responsivity to short days. When the ratio of testicular to ovarian tissue becomes large enough, the next short-day season evidently triggers the rapid further proliferation of testicular tissue and the involution of ovarian tissue that ends egg laying, begins secondary-male coloration, and changes self-fertilizing hermaphrodites into functional secondary males by converting ovotestes into secondary testes. Testicular activity, measured by percentages of self-fertilized eggs laid, was much lower throughout the hermaphrodite phase of fish early-reared at low temperature as contrasted with high, but ovarian activity, measured by numbers of eggs laid per unit time, was similar between fish earlyreared at low and at high temperature. Testicular activity rose each year with the increase in day lengths from the annual minimum. Later in the annual daylength cycle, ovarian activity rose in response to the much longer days, and testicular activity was proportionately depressed, i.e. inhibited