Chemical communication: chirality in elephant pheromones

Musth in male elephants is an annual period of heightened sexual activity and aggression that is linked to physical, sexual and social maturation. It is mediated by the release of chemical signals such as the pheromone frontalin, which exists in two chiral forms (molecular mirror images, or enantiomers). Here we show that enantiomers of frontalin are released by Asian elephants in a specific ratio that depends on the animal's age and stage of musth, and that different responses are elicited in male and female conspecifics when the ratio alters. This precise control of communication by molecular chirality offers insight into societal interactions in elephants, and may be useful in implementing new conservation protocols.     

亚洲象野外及圈养条件下食物成分分析

分析了采自云南思茅野生亚洲象在野外主要取食的37种野生植物材料,取自北京动物园象馆圈养亚洲象的5种植物饲料样品及1种颗粒饲料样品.用凯氏定氮法测定蛋白质质量分数,用乙醚浸提法测定粗脂肪质量分数,用酸碱水解法测定粗纤维质量分数,高温烘干至恒重法测定干物质的质量分数,煅烧法测灰分质量分数,以分析亚洲象主要食物成分,并对比圈养条件下亚洲象食物与野外食物营养成分的差别.研究发现:亚洲象的野生食物与动物园饲喂食物的主要营养成分没有显著性差异,但野生食物中的钙元素的质量分数普遍高于饲料食物.饲料食物中钙的含量不足可能是导致圈养亚洲象低血钙症的主要原因.     

True paternal care in a multi-male primate society

Although male parental care is rare among mammals, adult males of many cercopithecine primate species provide care for infants and juveniles. This care is often in the form of grooming, carrying, support in agonistic interactions, and protection against infanticide. For these behaviours to be interpreted as true parental care, males must selectively direct care towards their own offspring and this care must result in fitness benefits. With the exception of males defending probable offspring from infanticide, male primates living in multi-male, multi-female social groups have not been shown to selectively direct care towards their own offspring. We determined paternity for 75 juveniles in a population of wild savannah baboons (Papio cynocephalus) and collected data on interventions in agonistic disputes by adult males on behalf of juveniles as a form of male care. Here we show that adult males differentiate their offspring from unrelated juveniles and selectively support their offspring in agonistic disputes. As support in agonistic disputes is likely to contribute to rank acquisition and protect juveniles from injury and stress, this can be considered true parental care.     

Female mate-choice drives the evolution of male-biased dispersal in a social mammal

Dispersal has a significant impact on lifetime reproductive success, and is often more prevalent in one sex than the other. In group-living mammals, dispersal is normally male-biased and in theory this sexual bias could be a response by males to female mate preferences, competition for access to females or resources, or the result of males avoiding inbreeding. There is a lack of studies on social mammals that simultaneously assess these factors and measure the fitness consequences of male dispersal decisions. Here we show that male-biased dispersal in the spotted hyaena (Crocuta crocuta) most probably results from an adaptive response by males to simple female mate-choice rules that have evolved to avoid inbreeding. Microsatellite profiling revealed that females preferred sires that were born into or immigrated into the female's group after the female was born. Furthermore, young females preferred short-tenured sires and older females preferred longer-tenured sires. Males responded to these female mate preferences by initiating their reproductive careers in groups containing the highest number of young females. As a consequence, 11% of males started their reproductive career in their natal group and 89% of males dispersed. Males that started reproduction in groups containing the highest number of young females had a higher long-term reproductive success than males that did not. The female mate-choice rules ensured that females effectively avoided inbreeding without the need to discriminate directly against close kin or males born in their own group, or to favour immigrant males. The extent of male dispersal as a response to such female mate preferences depends on the demographic structure of breeding groups, rather than the genetic relatedness between females and males.     

在西双版纳国家级自然保护区用3S技术规划亚洲象生态走廊带初探

以亚洲象作为目标保护物种,通过野外收集的GPS数据和对西双版纳州卫星遥感图片的解析,判断在图片上不同颜色所代表的地形地貌,并结合其他影响亚洲象分布和迁徙的基本数据包括海拔、地形、河流、村寨以及公路等因素,初步探讨了西双版纳国家级自然保护区建立生态走廊带的规划区域及其可能性.     

Rapid deposition of subcutaneous areolar tissue in response to sexual stimulation in mice

Many of the reproductive processes of house mice are regulated exteroceptively by social cues. Puberty in a female mouse, for example, is a labile event that can be accelerated markedly if the young female is housed with an adult male. The relevant male stimuli in this case are a combination of pheromonal and tactile cues. The female's responses to these cues include an immediate, sequential release of gonadotropic and ovarian hormones, which in turn evoke a series of predictable changes in most of the female's reproductive tissues and culminate in the pubertal ovulation. I report here an unexpected consequence of exposing a young female mouse to a male, namely an intense response of a non-reproductive tissue. Specifically, young female mice experience a rapid thickening of their subcutaneous areolar tissue when they are exposed to males. The proximal cause of this response seems to be largely, but not exclusively, an enhanced secretion of ovarian oestrogen.     

Kin selection and cooperative courtship in wild turkeys

In the few species of birds in which males form display partnerships to attract females, one male secures most or all of the copulations. This leads to the question of why subordinate males help in the absence of observable reproductive benefits. Hamilton's concept of kin selection, whereby individuals can benefit indirectly by helping a relative, was a crucial breakthrough for understanding apparently altruistic systems. However in the only direct test of kin selection in coordinated display partnerships, partners were unrelated, discounting kin selection as an explanation for the evolution of cooperation. Here I show, using genetic measures of relatedness and reproductive success, that kin selection can explain the evolution of cooperative courtship in wild turkeys. Subordinate (helper) males do not themselves reproduce, but their indirect fitness as calculated by Hamilton's rule more than offsets the cost of helping. This result confirms a textbook example of kin selection that until now has been controversial and also extends recent findings of male relatedness on avian leks by quantifying the kin-selected benefits gained by non-reproducing males.     

2000-2010年中国幼儿(3-6岁)身体形态状况的动态研究

目的:运用文献资料、数理统计及逻辑分析等研究方法对2000年、2005年和2010年幼儿(3-6岁)三次全国体质监测数据分析研究,进行横向和纵向的比较,以期探讨全国十年间幼儿体质的特征和动态变化规律,为政府部门及时了解幼儿体质状况,更好的在"体育事业十二五规划"期间全面开展全民健身计划提供参考依据。方法:选择2000年、2005年和2010年中国幼儿(3-6岁)体质状况为研究对象,利用excel统计软件对2010年、2005年和2000年全国幼儿(3-6岁)身体形态的相关指标数据之间进行了平均数相减统计分析。结果:2000-2010年间的全国幼儿在身高、体重、坐高和胸围平均增长值普遍高,男性平均增长值大于女性;4-5岁年龄段的身高、坐高、体重和胸围平均增长值大于3-4岁和5-6岁年龄段;BMI指数平均增长值均有增高,男女无明显差距,同年龄段的平均增长值普遍提高;胸围指数平均增长值普遍减小,男女幼儿之间无明显差距,12000-2005年间平均值均减小,而2005-2010年间均增大,同年龄段的全国幼儿胸围指数平均增长值男大于女。     

幼年小家鼠社会等级的预测：行为学指标和亲缘关系影响

野生断乳雄性小家鼠社会等级的形成无亲缘关系组早于亲缘关系组，判断未来优势和从属个体的行为学指标也因亲缘关系的影响而不同，在无亲缘关系组，未来优势鼠的嗅体和远处探究２种社会探究显著地高于未来从属鼠；在亲缘关系组，未来优势鼠直接和跳跃行为显著地多于未来从属鼠。     

Testing the genetics underlying the co-evolution of mate choice and ornament in the wild

One of the most debated questions in evolutionary biology is whether female choice of males with exaggerated sexual displays can evolve as a correlated response to selection acting on genes coding for male attractiveness or high overall viability. To date, empirical studies have provided support for parts of this scenario, but evidence for all key genetic components in a natural population is lacking. Here we use animal-model quantitative genetic analysis on data from over 8,500 collared flycatchers (Ficedula albicollis) followed for 24 years to quantify all of the key genetic requirements of both fisherian and 'good-genes' models on sexual selection in the wild. We found significant additive genetic variances of all the main components: male ornament (forehead patch size), female mate choice for this ornament, male fitness and female fitness. However, when the necessary genetic correlations between these components were taken into account, the estimated strength of indirect sexual selection on female mate choice was negligible. Our results show that the combined effect of environmental influences on several components reduces the potential for indirect sexual selection in the wild. This study provides insight into the field of sexual selection by showing that genes coding for mate choice for an ornament probably evolve by their own pathways instead of 'hitchhiking' with genes coding for the ornament.     

不同生态环境下中华绒螯蟹的肉脂品质研究

选取长江野生、湖泊放流、网围养殖、池塘养殖4种生态环境的同规格成蟹,对其进行64个肉脂品质指标的测箅．结果表明,组内雌、雄可食部分比例、粗脂肪、灰分、脂肪酸、微量元素等指标差异较小;水分、粗蛋白、氨基酸等指标差异较大,粗蛋白、氨基酸各有显著差异的指标均为雄蟹小于雌蟹．同性别不同生态环境成蟹粗蛋白、氨基酸各指标的差异较小;可食部分比例、粗脂肪、水分、灰分、脂肪酸、微量元素等指标差异较大．综合均值比较结果和实践经验分别选取13个和16个指标,对4组雄蟹、4组雌蟹进行判别分析．判别结果表明所选取指标可较好反映中华绒螫蟹肉脂品质的差异．     

云南箭竹叶片对长期高温环境的适应性生理变化

通过对温室环境下培育6 a的云南箭竹与野外生长的云南箭竹的生理指标进行对比试验。结果表明:温室内高温环境条件下云南箭竹嫩叶、成熟叶、衰老叶的叶绿素a(Chl a)与叶绿素b(Chl b)含量均比野外条件下的高,但Chl a/b的比值却低于野外环境; 温室内云南箭竹竹叶中嫩叶、成熟叶的类胡萝卜素含量均高于野外云南箭竹竹叶中嫩叶、成熟叶的,但衰老叶中的类胡萝卜素含量情况却相反; 温室内成熟叶片及衰老叶片的可溶性糖含量比野外条件的高,除幼嫩叶片外,温室内成熟及衰老叶片超氧化物歧化酶的活性均比野外条件的低,而温室条件下成熟叶片过氧化氢酶活性比野外叶片的高; 除衰老叶片之外,温室内嫩叶与成熟叶中的丙二醛含量均比野外叶片的高。可见云南箭竹作为高山竹种尽管在温室中生长较长的时间,但依旧不能完全适应高温环境。     

Sexually antagonistic genetic variation for fitness in red deer

Evolutionary theory predicts the depletion of genetic variation in natural populations as a result of the effects of selection, but genetic variation is nevertheless abundant for many traits that are under directional or stabilizing selection. Evolutionary geneticists commonly try to explain this paradox with mechanisms that lead to a balance between mutation and selection. However, theoretical predictions of equilibrium genetic variance under mutation-selection balance are usually lower than the observed values, and the reason for this is unknown. The potential role of sexually antagonistic selection in maintaining genetic variation has received little attention in this debate, surprisingly given its potential ubiquity in dioecious organisms. At fitness-related loci, a given genotype may be selected in opposite directions in the two sexes. Such sexually antagonistic selection will reduce the otherwise-expected positive genetic correlation between male and female fitness. Both theory and experimental data suggest that males and females of the same species may have divergent genetic optima, but supporting data from wild populations are still scarce. Here we present evidence for sexually antagonistic fitness variation in a natural population, using data from a long-term study of red deer (Cervus elaphus). We show that male red deer with relatively high fitness fathered, on average, daughters with relatively low fitness. This was due to a negative genetic correlation between estimates of fitness in males and females. In particular, we show that selection favours males that carry low breeding values for female fitness. Our results demonstrate that sexually antagonistic selection can lead to a trade-off between the optimal genotypes for males and females; this mechanism will have profound effects on the operation of selection and the maintenance of genetic variation in natural populations.     

Study on Young Panicle Culture in vitro From Wild Rice of Different Genomes

Researches have been made on young panicle culture in vitro from wild rice of different genomes.Main results are as follows: 1. The induction frequencies of young panicle cultured in vitro from wild rice varied largely a relation to its genome. The optimal induction period of callus is the stamen and pistil differentiation stage of young panicle development. 2. Plantlets were regenerated through two ways: first, culture method, the induced calli were transferred onto differentiation medium; second, regenerate plantlets directly from young panicles of wild rice that were cultured on the differentiation medium. 3. The regeneration rate of green plantlets that obtained through cryopreservated calli in O. meyeriana was 10 times higher than that of control.     

Post-mating sexual selection increases lifetime fitness of polyandrous females in the wild

Females often mate with several males before producing offspring. Field studies of vertebrates suggest, and laboratory experiments on invertebrates confirm, that even when males provide no material benefits, polyandry can enhance offspring survival. This enhancement is widely attributed to genetic benefits that arise whenever paternity is biased towards males that sire more viable offspring. Field studies suggest that post-mating sexual selection biases fertilization towards genetically more compatible males and one controlled experiment has shown that, when females mate with close kin, polyandry reduces the relative number of inbred offspring. Another potential genetic benefit of polyandry is that it increases offspring survival because males with more competitive ejaculates sire more viable offspring. Surprisingly, however, there is no unequivocal evidence for this process. Here, by experimentally assigning mates to females, we show that polyandry greatly increases offspring survival in the Australian marsupial Antechinus stuartii. DNA profiling shows that males that gain high paternity under sperm competition sire offspring that are more viable. This beneficial effect occurs in both the laboratory and the wild. Crucially, there are no confounding non-genetic maternal effects that could arise if polyandry increases female investment in a particular reproductive event because A. stuartii is effectively semelparous. Our results therefore show that polyandry improves female lifetime fitness in nature. The threefold increase in offspring survival is not negated by a decline in maternal lifespan and is too large to be offset by an equivalent decline in the reproductive performance of surviving offspring.     

野外放归大熊猫和圈养大熊猫肠道正常菌群的研究

对四川卧龙中国保护大熊猫研究中心1只放归亚成体大熊猫和3只圈养亚成体大熊猫肠道正常菌群的种类、数量和分布情况进行了比较研究，结果鉴定出17种细菌，发现放归大熊猫和圈养大熊猫肠道优势菌群均为肠杆菌、肠球菌和乳杆菌，与圈养大熊猫相比，大熊猫放归野外后，肠道菌群中的肠球菌增多，肠杆菌和乳杆菌的数量有所下降，芽孢杆菌和酵母菌的检出率增大。     

Decisions about parental care in response to perceived paternity

Evolutionary ecologists are attempting to explain how parents make behavioural decisions about how much care to provide to their young. Theory predicts that when genetic relatedness to young is decreased by cuckoldry, for example, parents should reduce their care in favour of alternative broods that provide greater reproductive success. Experimental manipulation of perceived paternity has been used to test the theory, but such studies have generated mixed results. Some manipulations can fail to alter a parent's perceived paternity, whereas others may directly affect parental behaviour when, for instance, the manipulation involves capturing the parent. No study has demonstrated parental care adjustment in a manner uncomplicated by experimental design or life history correlates. Here I test the theory using the fact that nest-tending parental male bluegill sunfish (Lepomis macrochirus) can assess their paternity using both the visual presence of parasitic cuckolder males during spawning, and olfactory cues released by newly hatched eggs. By manipulating both types of cues I show that parental males dynamically adjust their parental care, favouring broods that are apparently most closely related. These results confirm the importance of genetic relatedness in parental care decision-making.     

Transmission distortion of t-haplotypes is due to interactions between meiotic partners

The T/t-complex of the mouse includes a series of recessive lethal and semi-lethal mutations but, despite such lethalities, mutant t-haplotypes are found in high frequency in wild mouse populations. This polymorphism is apparently maintained because heterozygous males preferentially transmit the t-bearing chromosome to their offspring. Despite many attempts to define the basis of the transmission ratio distortion, it has been unclear whether this is because t-bearing sperm have better than average fertilizing ability or whether +-bearing sperm in heterozygous males are rendered defective. To examine this point, we constructed male (XY in equilibrium XY) chimaeras containing +/+ and +/tw73 genotypes, marked respectively by albino and pigmented coat colours, and two isozyme variants. Such males produce a mixture of three different sperm types: +-bearing sperm from the +/+ genotype, +-bearing sperm from the +/t genotype, and t-bearing sperm from the +/t genotype. Appropriate matings can distinguish between these three types, and our data, reported here, show that t-bearing sperm in chimaeric mice maintain their advantage over their 'meiotic partners' but do not have any advantage over sperm from the +/+ genotype.     

Female feral fowl eject sperm of subdominant males

Paternity is often determined by competition between the ejaculates of different males. Males can also use particular behaviours or structures to manipulate how females use sperm. However, the ability of females to bias sperm utilization in favour of preferred males independently of male manipulation has not been demonstrated. Females are predicted to respond differentially to the sperm of different males when the reproductive interests of the sexes differ and when females are coerced into copulating. Here we show that in female feral fowl most copulations are coerced, and that females consistently bias sperm retention in favour of the preferred male phenotype. Females prefer to copulate with dominant males, but when sexually coerced by subordinate males, they manipulate the behaviour of dominant males to reduce the likelihood of insemination. If this fails, females differentially eject ejaculates according to male status in the absence of any male manipulation and preferentially retain the sperm of dominant males.     

Study on young panicle culturein vitro from wild rice of different genomes

Researches have been made on young panicle culturein vitro from wild rice of different genomes. Main results are as follows: 1. The induction frequencies of young panicle culturedin vitro from wild rice varied largely a relation to its genome. The optimal induction period of callus is the stamen and pistil differentiation stage of young panicle development. 2. Plantlets were regenerated through two ways: first, culture method, the induced calli were transferred onto differentiation medium; second, regenerate plantlets directly from young panicles of wild rice that were cultured on the differentiation medium. 3. The regeneration rate of green plantlets that obtained through cryopreservated calli inO. meyeriana was 10 times higher than that of control. Foundation item: Supported by the National Natural Science Foundation of China (39279436) Biography: SHU Li-hui(1937-), Professor, Research in plant tissue culture.