dominance

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  • 文章类型: Journal Article
    农药仍然是病虫害防治的基石,然而,它们的广泛和不合理的使用也助长了抵抗力的演变。这篇评论分析了从20世纪70年代到2023年的全球发表的实验数据,重点关注在选择性反应过程中表型和潜在的基因型变异是如何形成的。讨论从性别相关/母性抵抗的检查开始。有关母系遗传的观察丰富了我们对农药作用方式的认识,以联苯萘嗪为例。然而,抗性表型的主要控制归因于常染色体性状,观察到优势和单基因遗传的患病率很高,在田间菌株中也很明显。这一观察结果引起了人们对抗性管理策略的担忧,因为它们有可能加速抗性的传播。进一步探讨了优势水平与单基因遗传之间的相互作用,显性性状在多基因遗传中明显更为普遍。这一观察结果可能归因于代谢增强的积累。值得注意的是,进一步的分析表明,与其他选定的菌株相比,田间菌株单基因遗传的发生率更高,与既定的理论框架保持一致。总之,抗性的遗传结构因其在指导抗性管理策略和推进基础研究方面的关键作用而值得更多的研究关注。
    Pesticides remain a cornerstone in pest control, yet their extensive and irrational use also fuel the evolution of resistance. This review analyzes globally published experimental data spanning from the 1970s to 2023 to focus on how phenotypic and underlying genotypic variations are shaped during the selective response. The discussion commences with an examination of sex-linked/maternal resistance. Observations related to maternal inheritance have enriched our understanding of pesticide mode of action, notably exemplified by bifenazate. However, the predominant control of the resistant phenotype is attributed to autosomal traits, with a high prevalence of dominance and monogenic inheritance observed, also evident in field strains. This observation raises concerns regarding resistance management strategies due to their potential to accelerate the spread of resistance. The interplay between dominance levels and monogenic inheritance is further explored, with dominant traits being significantly more prevalent in polygenic inheritance. This observation may be attributed to the accumulation of enhanced metabolism. Notably, further analysis indicated that field strains exhibit a higher incidence of monogenic inheritance compared to other selected strains, aligning with established theoretical frameworks. In conclusion, the genetic architecture of resistance warrants increased research focus for its pivotal role in guiding resistance management strategies and advancing fundamental research.
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  • 文章类型: Journal Article
    尽管杂交作物品种是最受欢迎的农业创新之一,杂交作物育种的基本原理有时会被误解。杂交育种比近交育种速度慢,资源密集程度高,但是它可以通过同时反复选择和利用杂种优势来系统地改善种群。近交系亲本可以无限地繁殖自己及其F1后代,而近交系不能,因此,统一的近交系必须通过其近交亲本间接繁殖,以利用杂种优势。杂种优势是在进化时间内在种群水平上的全基因组非加性效应的预期结果。仅从分子遗传机制的角度来理解杂种优势可能是难以捉摸的,因为杂种优势可能是种群的新兴属性。杂种育种是反复种群改进的过程,以最大程度地提高杂种性能。杂交育种本身并不是杂种优势的最大化,也没有测试个体的随机组合来找到一个特殊的杂交体,也不能用杂种优势来代替人口的改善。尽管除了杂种育种之外,还有其他利用杂种优势的方法,例如使用开放授粉品种或克隆繁殖,它们目前并不适合所有作物或生产环境。使用基因组选择可以减少杂交育种的周期时间和成本,特别是通过快速建立杂种优势库,减少测试交叉,限制遗传变异的损失。在杂种作物育种计划中最佳使用基因组选择的悬而未决的问题仍然存在,比如如何选择异质池的创始人,优势效应在基因组预测中的重要性,用表型信息更新训练集的必要频率,以及如何保持遗传变异和防止有害等位基因的固定。
    Although hybrid crop varieties are among the most popular agricultural innovations, the rationale for hybrid crop breeding is sometimes misunderstood. Hybrid breeding is slower and more resource-intensive than inbred breeding, but it allows systematic improvement of a population by recurrent selection and exploitation of heterosis simultaneously. Inbred parental lines can identically reproduce both themselves and their F1 progeny indefinitely, whereas outbred lines cannot, so uniform outbred lines must be bred indirectly through their inbred parents to harness heterosis. Heterosis is an expected consequence of whole-genome non-additive effects at the population level over evolutionary time. Understanding heterosis from the perspective of molecular genetic mechanisms alone may be elusive, because heterosis is likely an emergent property of populations. Hybrid breeding is a process of recurrent population improvement to maximize hybrid performance. Hybrid breeding is not maximization of heterosis per se, nor testing random combinations of individuals to find an exceptional hybrid, nor using heterosis in place of population improvement. Though there are methods to harness heterosis other than hybrid breeding, such as use of open-pollinated varieties or clonal propagation, they are not currently suitable for all crops or production environments. The use of genomic selection can decrease cycle time and costs in hybrid breeding, particularly by rapidly establishing heterotic pools, reducing testcrossing, and limiting the loss of genetic variance. Open questions in optimal use of genomic selection in hybrid crop breeding programs remain, such as how to choose founders of heterotic pools, the importance of dominance effects in genomic prediction, the necessary frequency of updating the training set with phenotypic information, and how to maintain genetic variance and prevent fixation of deleterious alleles.
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  • 文章类型: Case Reports
    一名30岁的男性接受了双重脐带血移植(UCBT)治疗急性髓细胞性白血病(AML),并降低了强度。这些绳索具有相同的HLA类型,并且各自与患者5/6匹配。移植后,脐带2最初主导所有测试的细胞群。在第306天,我们观察到显性嵌合模式的异常逆转,其中Cord1主导了所有测试种群。
    对外周血和骨髓样品进行基于聚合酶链反应(PCR)的短串联重复(STR)测定。操作来自外周血的白血细胞(WBC)群体用于测试以产生富含CD3、CD33和CD56的亚群。
    第+77天的嵌合性研究显示如下:第1索:44%-CD3;0%-CD33;16%-CD56;第2索:56%-CD3;100%-CD33;84%-CD56。Cord2最初在所有测试的细胞群中占主导地位。在移植后第306天进行的嵌合研究发现了显性嵌合模式的逆转,其中1号脐带现在在所有细胞群中占主导地位(1号脐带:82%-CD3;>95%-CD33;67%-CD56;2号脐带:18%-CD3;<5%-CD33;33%-CD56)。在+127和+244天之间,患者的血型从BRh阳性转变为ARh阴性。
    患者血型的变化确定了显性嵌合模式的晚期逆转。这是一种罕见的情况,以前只引用过一次,这与已发表的数据不一致,即在绝大多数病例中,早期高CD3计数和第+100天未分离的骨髓嵌合体占优势预测双UCBT的长期脐带优势。
    A 30-year-old man underwent double umbilical cord blood transplantation (UCBT) for acute myeloid leukemia (AML) with reduced intensity conditioning. The cords had identical HLA types and were each a 5/6 match to the patient. Following transplantation, cord 2 initially dominated all tested cell populations. At day +306, we observed an unusual reversal of dominance chimerism pattern in which cord 1 instead dominated all tested populations.
    Polymerase chain reaction (PCR)-based short tandem repeat (STR) assays were performed on the peripheral blood and bone marrow samples. The white blood cell (WBC) populations from the peripheral blood were manipulated for testing to create subpopulations enriched for CD3, CD33, and CD56.
    Chimerism studies on day +77 showed the following: cord 1: 44%-CD3; 0%-CD33; 16%-CD56; cord 2: 56%-CD3; 100%-CD33; 84%-CD56. Cord 2 initially dominated in all tested cell populations. Chimerism studies performed on post-transplantation day +306 uncovered a reversal of dominance chimerism pattern in which cord 1 now dominated in all cell populations (cord 1: 82%-CD3; >95%-CD33; 67%-CD56; cord 2: 18%-CD3; <5%-CD33; 33%-CD56). Between days +127 and  +244, the patient\'s blood type shifted from B Rh-positive to A Rh-negative.
    The change in the patient\'s blood type identified a late reversal of dominance chimerism pattern. This is a rare occurrence, previously cited only once, which is inconsistent with published data that early high CD3 counts and unseparated bone marrow chimerism predominance at day +100 predict long-term cord dominance in double UCBT in the vast majority of cases.
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  • 文章类型: Journal Article
    Decades of research in behavioral endocrinology has implicated the gonadal hormone testosterone in the regulation of mating effort, often expressed in primates in the form of aggressive and/or status-striving behavior. Based on the idea that neuroendocrine axes influence each other, recent work among humans has proposed that links between testosterone and indices of status-striving are rendered conditional by the effects of glucocorticoids. The Dual Hormone hypothesis is one particular instance of this argument, predicting that cortisol blocks the effects of testosterone on dominance, aggression, and risk-taking in humans. Support for the Dual Hormone hypothesis is wide-ranging, but considerations of theoretical ambiguity, null findings, and low statistical power pose problems for interpreting the published literature. Here, we contribute to the development of the Dual Hormone hypothesis by (1) critically reviewing the extant literature-including p-curve analyses of published findings; and, (2) \"opening the file drawer\" and examining relationships between testosterone, cortisol, and status-striving personality features in seven previously published studies from our laboratories (total N = 718; median N per feature = 318) that examined unrelated predictions. Results from p-curve suggest that published studies have only 16% power to detect effects, while our own data show no robust interactions between testosterone and cortisol in predicting status-striving personality features. We discuss the implications of these results for the Dual Hormone hypothesis, limitations of our analyses, and the development of future research.
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  • 文章类型: Journal Article
    Humpback whales (Megaptera novaeangliae) are seasonal breeders, annually migrating from high-latitude summer feeding grounds to low-latitude winter breeding grounds. The social matrix on the winter grounds is a loose network of interacting individuals and groups and notably includes lone males that produce long bouts of complex song that collectively yield an asynchronous chorus. Occasionally, a male will sing while accompanying other whales. Despite a wealth of knowledge about the social matrix, the full characterization of the mating system remains unresolved, without any firm consensus, as does the function of song within that system. Here, I consider and critically analyse three proposed functions of song that have received the most attention in the literature: female attraction to individual singers, determining or facilitating male-male interactions, and attracting females to a male aggregation within the context of a lekking system. Female attraction suggests that humpback song is an advertisement and invitation to females, but field observations and song playback studies reveal that female visits to individual singers are virtually absent. Other observations suggest instead that females might convey their presence to singers (or to other males) through the percussive sounds of flipper or tail slapping or possibly through vocalizations. There is some evidence for male-male interactions, both dominance and affiliative: visits to singers are almost always other lone males not singing at that time. The joiner may be seeking a coalition with the singer to engage cooperatively in attempts to obtain females, or may be seeking to disrupt the song or to affirm his dominance. Some observations support one or the other intent. However, other observations, in part based on the brevity of most pairings, suggest that the joiner is prospecting, seeking to determine whether the singer is accompanying a female, and if not soon departs. In the lekking hypothesis, the aggregation of vocalizing males on a winter ground and the visits there by non-maternal females apparently for mating meet the fundamental definition of a lekking system and its role though communal display in attracting females to the aggregation, although not to an individual singer. Communal singing is viewed as a form of by-product mutualism in which individuals benefit one another as incidental consequences of their own selfish actions. Possibly, communal singing may also act to stimulate female receptivity. Thus, there are both limitations and merit in all three proposals. Full consideration of song as serving multiple functions is therefore necessary to understand its role in the mating system and the forces acting on the evolution of song. I suggest that song may be the prime vector recruiting colonists to new winter grounds pioneered by vagrant males as population pressures increase or as former winter grounds become unavailable or undesirable, with such instances documented relatively recently. Speculatively, song may have evolved historically as an aggregating call during the dynamic ocean conditions and resulting habitat uncertainties in the late Miocene-early Pliocene epochs when Megaptera began to proliferate. Early song may have been comprised of simpler precursor sounds that through natural selection and ritualization evolved into complex song.
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  • 文章类型: Journal Article
    Lower limb dominance (or lateral preference) could potentially effect functional performance. Clinicians are often asked to make judgements as to when a patient has sufficiently \"recovered\" from an injury, typically using strength and dynamic performance outcome measures. The primary purpose of this study was to systematically review the literature in relation to limb dominance within active adult populations and discuss some limitations to current methods and relate this to current clinical practice. A search of MEDLINE and CINAHL and EMBASE databases and reference lists of those articles identified was performed. Eleven articles were selected for meta-analysis. There was no statistical effect of limb dominance for any of the functional tests: isokinetic quadriceps and hamstring tests, hamstring:quadriceps ratios, single-leg hop for distance, single-leg vertical jump and vertical ground reaction force following a single-leg vertical jump. Pooled symmetry values varied from 94.6% to 99.6% across the tests, above the clinically accepted benchmark of 90% used in clinical practice. Although the results of this study must be used with discretion, asymmetries in the tasks described in this analysis should be viewed as undesirable and remedied accordingly. Further research is needed to quantify asymmetries, particularly in relation to sport-specific contexts.
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  • 文章类型: Journal Article
    The family Cichlidae is well-known for pair-formation, parental care, territoriality, elaborate courtship and social organization. Do cichlids use chemical communication to mediate any of these behaviours? Early studies suggest that parent cichlids can discriminate between conspecific and heterospecific wrigglers (but not eggs) using olfactory cues. Some species are able to discriminate between their own brood and other conspecific broods based on olfaction. The young recognise conspecific adults (although not necessarily their parents) through the odorants they release. In both scenarios, protection of the young from predation is the likely selective force. Some male cichlids use urinary pheromones during courtship and spawning to attract females and induce ovulation. Females--in their turn--may base their mate-choice in part on assessment of those self-same pheromones. The same pheromonal system may be involved in establishing and maintaining the social hierarchies in lek-breeding cichlids. Individual recognition is also mediated by chemical communication. Finally, there is ample behavioural evidence that cichlids--like ostariophysan fish--release alarm cues that alert conspecifics to predation danger. Although the effects of these cues may be similar (e.g., increased shelter use, tighter schooling), they are different substances which remain to be identified. Cichlids, then, use chemical communication associated with many different behaviours. However, given the diversity of cichlids, little is known about the mechanisms of chemical communication or the chemical identity of the cues involved. The aim of this mini-review is to persuade those working with cichlids to consider the involvement of chemical communication, and those working in chemical communication to consider using cichlids.
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