动物生殖与生理研究:从基础到应用

<正>动物生殖与生理研究一直与人类对动物的认知和利用紧密相联.特别是近年来随着生命科学和生物技术的进步和发展,动物生殖与生理研究已呈现出新的理论发展和应用潜力.鱼类由于具有繁育力强、体     

冬眠与免疫

免疫系统是机体防御机制的重要组份。冬眠季节,冬眠动物免疫系统的结构退化、机能抑制,与动物整体的活动相适应,春季恢复。综述民哺乳动物中枢与外周淋巴器官和免疫反应的季节性变化。对调控免疫系统变化的环境因素和受环境因素影响的内源性生理节律对免疫系统冬眠季节的抑制机理作了介绍,更从冬眠对免疫的抑制联系到冬眠净化机体内外环境、冬眠与肿瘤、冬眠与辐射乃至冬眠与长寿等临床关心的实验研究作了简要介绍。     

社会性昆虫级型和行为分化机制研究进展

社会性的出现是生物演化过程中的重要革新, 理解社会性的演化和调控机制具有重要的理论和实际意义。社会性昆虫的个体间有着明显的级型分化和劳动分工, 这有利于它们适应复杂的环境变化。理解社会性昆虫如何产生不同的形态、行为和生活史特性, 一直是进化和发育生物学的重要目标。随着测序技术的不断更新及生物信息学的快速发展, 已经有众多关于社会性昆虫级型和行为分化机制的研究报道。本文通过整理社会性昆虫研究的已有成果, 从环境因素、生理调控和分子机制等方面对社会性昆虫级型和行为分化机制相关研究进展进行了综述, 并对未来的研究方向做出了展望。根据现有证据, 社会性昆虫所生活的生物环境(食物营养、信息素、表皮碳氢化合物)和非生物环境(温度、气候等)均能直接或间接影响社会性昆虫级型和行为的分化; 保幼激素、蜕皮激素、类胰岛素及生物胺等内分泌激素和神经激素对社会性昆虫的级型和行为分化也有重要的调控作用; 此外, 遗传因素、新基因等DNA序列或基因组结构上的变化以及表观遗传修饰、基因的差异表达等基因调控机制均能不同程度地影响社会性昆虫的行为分化。本文建议加强昆虫纲其他社会性类群如半翅目蚜虫和缨翅目蓟马等的社会性行为及其演化机制的研究, 以加深对社会性昆虫起源及其行为演化的理解和认识。     

动物的警戒行为——回顾及展望

警戒行为是动物对群体内部或外部刺激的行为反应,主要表现为抬头环视周围环境,具有反捕食和社会性监视功能,有利于个体适合度的增加。诸多研究表明,多种因素可以影响到动物警戒行为的强度和模式。内部因素主要包括个体的年龄、性别、所处空间位置和群体大小等,外部因素主要是捕食风险和人类活动的干扰。近年来,动物警戒同步性研究引起了广泛关注。同步警戒和协调警戒对立于独立警戒而存在,强调个体能够受到周围个体警戒状态的影响,继而表现出相同或相反的行为,并且其强度与群体大小等因素有关。在今后的研究中,可以在警戒行为影响因素和同步性方面进行更加深入而全面的探索。此外,警戒行为的个体差异和时空变化等也将是重要的研究方向。     

广东省生物资源应用研究所简介

正广东省生物资源应用研究所是公益一类事业单位,成立于1958年,前称中国科学院中南昆虫研究所,1972年改称广东省昆虫研究所,2015年改称广东省生物资源应用研究所,隶属广东省科学院,是极具华南地区特色、从事生物资源研发的知名研究机构,是广东省昆虫学会、白蚁学会、动物学会和养蜂学会的挂靠单位。主办中文核心期刊《环境昆虫学报》。生物资源所围绕野生动物保育与资源利用、有害生物监控、现代生物技术应用三大研究方向,主要开展珍稀野生动物(包括昆虫)资源评价和保育;特种经济动物和实验动物的育种、养殖和创     

哺乳动物的生理应激反应及其生态适应性

应激反应是哺乳动物的基本生理现象之一。目前,与应激有关的研究主要来自生物医学和神经内分泌学。虽然Hans Selye 提出了个体对应激的普遍性适应综合症概念,但目前的研究还主要集中于应激对个体的负效应以及与应激相关的疾病研究。然而,从进化角度似乎很难理解在数亿年的进化过程中,动物应激反应仅简单地
进化为影响个体健康并导致个体患病的一种生理过程。本文从进化的角度,综述了应激反应与动物繁殖对策的关系以及个体对环境应激源的应对类型,并阐述了动物应激反应的适应和进化意义。     

摘要

实验动物环境丰富 环境丰富又称环境丰容（environmental enrichment）,是指对圈养动物所处的物理环境进行修饰,改善环境质量,提高其生物学功能,如生殖成功率和适应性等,从而提高其福利水平。环境丰富这一概念最早在1925年被提出和应用。环境丰富化最主要的精神,就是不要让动物觉得无聊,让动物满足本能需求,包括觅食、筑巢、 寻找隐蔽物体等的本能。丰富化的环境可使动物表现正常生理,防止动物产生异常的行为与不正常的身心发展,避免内分泌或免疫系统异常常。虽然采用环境丰富技术会使得实验动物的生存状态改善,但是环境丰富度的增加,会增加实验结果的变异。总的来说,实验动物环境丰富研究领域仍然存在很多未知的问题。     

蜜蜂无政府主义蜂群的研究进展

西方蜜蜂Apis mellifera作为典型的社会性昆虫, 最重要的特征是生殖劳动分工。蜂王垄断蜂群的生殖权利, 工蜂生殖功能受到抑制, 从事除产卵和交配以外的所有职能。而在无政府主义蜂群中, 即使蜂王存在, 也有较多工蜂的卵巢激活并产卵, 蜂群中大多数雄蜂是工蜂的后代。这些特殊蜂群为正常蜂群工蜂不育机制研究提供了绝佳的反例材料。本文对无政府主义蜂群的行为特征、 产生条件、 遗传基础等研究进行了综述。无政府主义蜂群中有较多的工蜂产卵, 且工蜂所产卵能够逃避工蜂监督, 这种行为的产生受环境、 遗传组成、 基因表达等多种因素的影响, 并且遗传结构体系复杂, 参与调控的基因数量多。无政府主义蜂群行为机制的研究为工蜂不育机制的揭示及其他社会性昆虫工职不育基因的筛选和功能研究提供借鉴。     

影响鸟类生殖内分泌的环境因子概述

生殖内分泌是调控鸟类繁殖行为的重要生理过程,环境因子则是影响鸟类生殖内分泌的关键因素。光周期是调节大多数温带鸟类生殖内分泌的关键环境因子。日照延长可作用于下丘脑一垂体一性腺轴（HPG）刺激繁殖活跃,日照缩短则刺激下丘脑释放GnIH抑制繁殖。在沙漠、热带地区以及食物条件不可预见的地区,降雨、食物及温度也可成为影响鸟类生殖内分泌的重要因素。环境内分泌干扰物等人类活动因素也会对野生鸟类的生殖内分泌产生一定的影响。     

人抑制素的分子结构及其生物学特性

抑制素是性腺产生的一种糖蛋白激素,由双硫键联结的两个不同的亚单位(即α和β肽链)组成,抑制垂体促性腺激素(尤其是FSH)的产生和分泌。近年来,国外许多学者十分关注抑制素在人类生殖生理活动的重要地位,并为寻找特异性干扰精子发生和滤泡生长的节育途径,探索不育症的机理而进行深入的研究。本文简要综述人抑制素的分子结构及其生物学特性。     

小型哺乳动物的繁殖投入与繁殖成功率

动物的繁殖活动关系到整个种群的生存与灭绝, 繁殖投入和繁殖成功率是繁殖生态学研究的重要内容。从繁殖投入的划分入手, 综述了小型哺乳动物的繁殖投入和繁殖成功率之间的关系及其影响因素、分子生物学技术在繁殖生态学中的应用等, 阐述了小型哺乳动物能够根据自身的状态调整每次繁殖活动中的时间投入和能量分配, 采取不同的繁殖对策。这些繁殖对策是长期自然选择的结果, 其目的都是为了最大限度地提高自身的适合度。并且指出分子生物学技术在繁殖生态学中的应用将大大加快这一研究领域的快速发展。     

Bateman revisited: the reproductive tactics of female primates

The breeding system of an animal population is thought to depend on the ability of one sex (usually the male) to acquire mates, either directly through association with females or indirectly through defense of the resources desired by females. The sex that contributes most to infant care (usually the female) is constrained by parental involvement and thereby limits reproduction of the opposite sex. Accordingly, males, but not females, enhance their reproductive success by acquiring additional mates. This classical view has emphasized the role of male-male competition in sexual selection, at the expense of fully exploring the potential for female choice. A more recent shift in focus has revealed substantial variation in female reproductive success and increasingly accentuates the importance of female intrasexual competition and male mate choice. A comparative review of primate reproduction, therefore, challenges expectations of male control and female compliance, and calls for a comprehensive treatment of costs and benefits that extends beyond conventional mention of heavy female investment versus male negligence or absenteeism. For individuals that manipulate their social environment or reproductive output, consideration of more subtle, even cryptic, aspects of female behavior and physiology (e.g., social strategizing, sexual solicitation or rejection, sexual advertisement or concealed ovulation, multiple mating, and reproductive failure) raises the question of whether females can be effectively 'monopolized.' Widespread patterns that counter Bateman's paradigm call for a reexamination of the predictions generated by dichotomizing gametes into 'expensive eggs' and 'cheap sperm,' and encourage continued mechanistic research focused on conception quality rather than quantity.     

Does it pay to delay? Flesh flies show adaptive plasticity in reproductive timing

Life-history plasticity is widespread among organisms. However, an important question is whether it is adaptive. Most models for plasticity in life-history timing predict that animals, once they have reached the minimal nutritional threshold under poor conditions, will accelerate development or time to reproduction. Adaptive delays in reproduction are not common, especially in short-lived species. Examples of adaptive reproductive delays exist in mammalian populations experiencing strong interspecific (e.g., predation) and intraspecific (e.g., infanticide) competition. But are there other environmental factors that may trigger an adaptive delay in reproductive timing? We show that the short-lived flesh fly Sarcophaga crassipalpis will delay reproduction under nutrient-poor conditions, even though it has already met the minimal nutritional threshold for reproduction. We test whether this delay strategy is an adaptive response allowing the scavenger time to locate more resources by experimentally providing supplemental protein pulses (early, mid and late) throughout the reproductive delay period. Flies receiving additional protein produced more and larger eggs, demonstrating a benefit of the delay. In addition, by tracking the allocation of carbon from the pulses using stable isotopes, we show that flies receiving earlier pulses incorporated more carbon into eggs and somatic tissue than those given a later pulse. These results indicate that the reproductive delay in S. crassipalpis is consistent with adaptive post-threshold plasticity, a nutritionally linked reproductive strategy that has not been reported previously in an invertebrate species.     

Recovery of reproductive function by prairie deermice (Peromyscus maniculatus bairdii) from asymptotic populations

Prairie deermice greater than 100 days of age and non-reproductive in laboratory populations provided with surplus food and water were paired either with fertile mates or with other inhibited population animals. Following pairing, more than 75 per cent of all animals reproduced. The rates of reproductive recovery did not differ significantly between males and females. The average time required for reproduction by population animals paired with proven mates was less than that for pairs composed of population animals. The significantly slower rate of reproductive recovery for population pairs suggests that mutual stimulation is involved in recovery and is initially lacking or minimal in these pairs. A period of physiological and behavioural adjustment following removal from the populations appears necessary before reproduction. Mechanisms preventing reproduction within the populations are unknown.     

Female competition and its evolutionary consequences in mammals

Following Darwin's original insights regarding sexual selection, studies of intrasexual competition have mainly focused on male competition for mates; by contrast, female reproductive competition has received less attention. Here, we review evidence that female mammals compete for both resources and mates in order to secure reproductive benefits. We describe how females compete for resources such as food, nest sites, and protection by means of dominance relationships, territoriality and inter‐group aggression, and by inhibiting the reproduction of other females. We also describe evidence that female mammals compete for mates and consider the ultimate causes of such behaviour, including competition for access to resources provided by mates, sperm limitation and prevention of future resource competition. Our review reveals female competition to be a potentially widespread and significant evolutionary selection pressure among mammals, particularly competition for resources among social species for which most evidence is currently available. We report that female competition is associated with many diverse adaptations, from overtly aggressive behaviour, weaponry, and conspicuous sexual signals to subtle and often complex social behaviour involving olfactory signalling, alliance formation, altruism and spite, and even cases where individuals appear to inhibit their own reproduction. Overall, despite some obvious parallels with male phenotypic traits favoured under sexual selection, it appears that fundamental differences in the reproductive strategies of the sexes (ultimately related to parental investment) commonly lead to contrasting competitive goals and adaptations. Because female adaptations for intrasexual competition are often less conspicuous than those of males, they are generally more challenging to study. In particular, since females often employ competitive strategies that directly influence not only the number but also the quality (survival and reproductive success) of their own offspring, as well as the relative reproductive success of others, a multigenerational view ideally is required to quantify the full extent of variation in female fitness resulting from intrasexual competition. Nonetheless, current evidence indicates that the reproductive success of female mammals can also be highly variable over shorter time scales, with significant reproductive skew related to competitive ability. Whether we choose to describe the outcome of female reproductive competition (competition for mates, for mates controlling resources, or for resources per se) as sexual selection depends on how sexual selection is defined. Considering sexual selection strictly as resulting from differential mating or fertilisation success, the role of female competition for the sperm of preferred (or competitively successful) males appears particularly worthy of more detailed investigation. Broader definitions of sexual selection have recently been proposed to encompass the impact on reproduction of competition for resources other than mates. Although the merits of such definitions are a matter of ongoing debate, our review highlights that understanding the evolutionary causes and consequences of female reproductive competition indeed requires a broader perspective than has traditionally been assumed. We conclude that future research in this field offers much exciting potential to address new and fundamentally important questions relating to social and mating‐system evolution.     

Population regulation by habitat heterogeneity or individual adjustment?

1. The habitat heterogeneity (HHH) and individual adjustment (IAH) hypotheses are commonly proposed to explain a decrease in reproduction rate with increasing population density. Higher numbers of low-quality territories with low reproductive success as density increases lead to a decrease in reproduction under the HHH, while more competition at high density decreases reproduction across all territories under the IAH. 2. We analyse the influence of density and habitat heterogeneity on reproductive success in eight populations of long-lived territorial birds of prey belonging to four species. Sufficient reliability in distinguishing between population-wide, site-specific and individual quality effects on reproduction was granted through the minimal duration of 20 years of all data sets and the ability to control for individual quality in five of them. 3. Density increased in five populations but reproduction did not decrease in these. Territory occupancy as a surrogate of territory quality correlated positively with reproductive success but only significantly so in large data sets with more than 100 territories. 4. Reproductive success was always best explained by measures of territory quality in multivariate models. Direct or delayed (t-1) population density entered very few of the best models. Mixed models controlling for individual quality showed an increasing reproductive performance in older individuals and in those laying earlier, but measures of territory quality were also always retained in the best models. 5. We find strong support for the habitat heterogeneity hypothesis but weak support for the individual adjustment hypothesis. Both individual and site characteristics are crucial for reproductive performance in long-lived birds. Proportional occupancy of territories enables recognition of high-quality territories as preferential conservation targets.     

The evolution of bourgeois, parasitic, and cooperative reproductive behaviors in fishes

Among vertebrate classes, fishes exhibit by far the greatest variability in competitive and cooperative behaviors in male reproduction. Scramble competition between reproductive males is one possibility. Another possibility occurs when resources, mates, or locations can be monopolized, in which case males may invest in primary access to fertilizations by adopting a "bourgeois" strategy, or they may employ alternative mating tactics to evade the reproductive monopoly of other males. Adaptations in morphology, physiology, and behavior to bourgeois and alternative phenotypes are highly divergent. Here I review the functional characteristics that differ between bourgeois and parasitic phenotypes, and discuss the variability of alternative reproductive tactics at the levels of plasticity, determination, and selection. Examples will illustrate the importance of ecology, and will suggest that variation in reproductive tactics is largely adaptive. Behavioral solutions to competition for mates and fertilizations often involve agonistic behavior and conflict, but also cooperation among competitors (e.g., when subordinate males pay a price to bourgeois males for gaining access to fertilizable eggs). Application of molecular genetic tools has helped to uncover intricate sexual and social relationships in various fish species, including species that display some of the most complex reproductive and social patterns known among the vertebrates.     

Infanticide in the evolution of reproductive synchrony: effects on reproductive success

Synchronous breeding in animals and plants has stimulated both a theoretical and empirical examination of the possible benefits of active synchronization. The selective pressures of predation and infanticide are the strongest candidates proposed to explain the evolution of reproductive synchrony. Alternatively, breeding asynchronously with conspecifics may ensure a greater availability of resources per breeder. However, the possible fitness benefits resulting from active asynchronization have not yet received attention in evolutionary ecology. Here we present a hypothesis, based on a graphical model, illustrating the costs and benefits of the two modes of reproduction. We tested the hypothesis empirically using a 2 x 2 full factorial study design, where reproductive synchrony and infanticide tactics were manipulated in enclosed populations of the bank vole. The results reveal a relationship between infanticide tactics and breeding synchrony as illustrated by our hypothesis. In general, female reproductive success (number and size of offspring surviving to weaning) was significantly lower in infanticidal populations. Moreover, an asynchronous breeding pattern proved to be advantageous in the noninfanticidal population but this advantage of asynchrony was lost as infanticide became common in the population. Our findings support the idea that synchronous reproduction could have evolved as a counterstrategy against infanticide.     

Exposure to a novel male during late pregnancy influences subsequent growth of offspring during lactation

In mammals, allocation to reproduction can either be primed or suppressed in relation to cues from other individuals. Some conspecifics (e.g. potential mates) may enhance an individual's ability to reproduce but others may have a detrimental effect on reproductive success. One widely studied response to conspecific cues, the ‘Bruce effect’, occurs when pregnant females abort their pregnancies after exposure to a novel male. It has been suggested that this response has evolved as a counter‐tactic to the threat of infanticide posed by novel males. In some species, like mice, pregnancy termination will only occur if females are exposed to the unfamiliar male during a brief critical period early in pregnancy, which is surprising considering that an unfamiliar male threatens infanticide whenever present, and in particular near to birth. We demonstrate that female mice experiencing novel males during late pregnancy also alter their investment in progeny, but in a more subtle manner than previously observed. Females exposed to an unfamiliar male during late pregnancy give birth to offspring of a comparable weight to those produced by females exposed to the paternal male, but these offspring grow more slowly over lactation. As a consequence, offspring from these females weigh less at weaning. Modification of their growth trajectory, however, allows these offspring to catch up to normal weights by adulthood. Thus, cues of unfamiliar males, and possibly their associated threat of infanticide, can produce more wide‐ranging effects on maternal investment than previously recognized.     

Reproductive suppression in female primates: A review

Reproductive performance is the currency of evolution. All things being equal, an organism should reproduce as often as possible. The puzzling questions in evolutionary biology, therefore, are not how and why an organism does reproduce, but rather how and why an organism does not reproduce. It is difficult to understand why any individual, particularly a female, might forestall reproduction when one of the biggest limitations for female mammalian reproduction is time (that is, reproductive lifespan). 1 The answer, now widely cited throughout behavioral ecology is quite simple: Reproductive suppression can be an adaptive strategy. 2