The capacious hologenome

Blending disciplines can be transformative in science, yet interdisciplinary mergers should not escape healthy skepticism. Indeed, the history of biology shows us that debates about the relative importance of nuclear genetics vs. microbial symbiosis in eukaryotic biology are among the most engaging. Today's technology may help resolve this century old debate as it illuminates the interwoven genomics and functions of symbionts with their host genome. Thus, we can now assert that all subdisciplines of zoology require microbiology. Although controversial to some, the evidence from studies of host-associated microbial communities indicates that metazoans are hologenomes – interconnected compositions of animal and microbes.     

兔食管静脉曲张模型的建立

目的建立新西兰兔的食管静脉曲张模型,为下一步的临床研究提供可靠的小型动物模型。方法采用门静脉左支完全夹闭法造模,并通过外观、超声、胃镜等检查检验手段对造模结果加以评估。结果术后8周存活动物100%可见食管静脉曲张。结论通过门静脉左支夹闭法,基本可以建立兔食管静脉曲张模型。     

弱硅化腕足类化石酸处理方法的改进

本文介绍了一种获取灰岩中弱硅化腕足类化石的酸处理方法。以四川省布拖县浪珠乡万吨山剖面上奥陶统铁足菲克组近顶部的生屑灰岩为实验对象, 通过准备样品、悬吊样品、配酸解液、酸解样品等实验流程, 配合遮盖液(如二乙酸纤维素丙酮溶液)的使用, 可获得保存精美的、弱硅化的腕足类实体化石, 且该化石保存有主突起、铰齿和匙形台等重要的细小结构。相较于传统方法, 该方法可获取硅化程度更低的壳相化石。该方法为灰岩中其他多门类弱硅化保存的化石之酸解分析提供了新思路和参考。     

Protein markers of Bursaphelenchus xylophilus Steiner & Buhrer, 1934 (Nickle, 1970) populations using quantitative proteomics and character compatibility

The Pine Wood Nematode (PWN) Bursaphelenchus xylophilus is a severe forest pathogen in countries where it has been introduced and is considered a worldwide quarantine organism. In this study, protein markers for differentiating populations of this nematode were identified by studying differences among four selected Iberian and one American population. These populations were compared by quantitative proteomics (iTRAQ). From a total of 2860 proteins identified using the public database from the B. xylophilus genome project, 216 were unambiguous and significantly differentially regulated in the studied populations. Comparisons of their pairwise ratio were statistically treated and supported in order to convert them into discrete character states, suggesting that 141 proteins were not informative as population specific markers. Application of the Character Compatibility methodology on the remaining 75 proteins (belonging to families with different biological functions) excludes 27 which are incompatible among them. Considering only the compatible proteins, the method selects a subset of 30 specific unique protein markers which allowed the compared classification of the Iberian isolates. This approach makes it easier search for diagnostic tools and phylogenetic inference within species and populations of a pathogen exhibiting a high level of genetic diversity.     

Specific protein changes contribute to the differential muscle mass loss during ageing

In the skeletal muscle, the ageing process is characterized by a loss of muscle mass and strength, coupled with a decline of mitochondrial function and a decrease of satellite cells. This profile is more pronounced in hindlimb than in forelimb muscles, both in humans and in rodents. Utilizing light and electron microscopy, myosin heavy chain isoform distribution, proteomic analysis by 2D‐DIGE, MALDI‐TOF MS and quantitative immunoblotting, this study analyzes the protein levels and the nuclear localization of specific molecules, which can contribute to a preferential muscle loss. Our results identify the molecular changes in the hindlimb (gastrocnemius) and forelimb (triceps) muscles during ageing in rats (3‐ and 22‐month‐old). Specifically, the oxidative metabolism contributes to tissue homeostasis in triceps, whereas respiratory chain disruption and oxidative‐stress‐induced damage imbalance the homeostasis in gastrocnemius muscle. High levels of dihydrolipoyllysine‐residue acetyltransferase (Dlat) and ATP synthase subunit alpha (Atp5a1) are detected in triceps and gastrocnemius, respectively. Interestingly, in triceps, both molecules are increased in the nucleus in aged rats and are associated to an increased protein acetylation and myoglobin availability. Furthermore, autophagy is retained in triceps whereas an enhanced fusion, decrement of mitophagy and of regenerative potential is observed in aged gastrocnemius muscle.     

Skin aging caused by intrinsic or extrinsic processes characterized with functional proteomics

The skin provides protection against environmental stress. However, intrinsic and extrinsic aging causes significant alteration to skin structure and components, which subsequently impairs molecular characteristics and biochemical processes. Here, we have conducted an immunohistological investigation and established the proteome profiles on nude mice skin to verify the specific responses during aging caused by different factors. Our results showed that UVB‐elicited aging results in upregulation of proliferating cell nuclear antigen and strong oxidative damage in DNA, whereas chronological aging abolished epidermal cell growth and increased the expression of caspase‐14, as well as protein carbonylation. Network analysis indicated that the programmed skin aging activated the ubiquitin system and triggered obvious downregulation of 14‐3‐3 sigma, which might accelerate the loss of cell growth capacity. On the other hand, UVB stimulation enhanced inflammation and the risk of skin carcinogenesis. Collectively, functional proteomics could provide large‐scale investigation of the potent proteins and molecules that play important roles in skin subjected to both intrinsic and extrinsic aging.     

Wild Animal Training: A Glance at Circuses and Hediger's Viewpoint

Historically, zoos have shared common features with circuses despite recent animosity toward them: Exhibition of wild animals in captivity. Experienced circus professionals can provide insight into the nature of wild animals from their sensitivity to man-made environmental components, potentially dangerous human errors, to animal escapes. These are told in numerous behind-the-scenes episodes. Zoos and circuses also have common needs such as improved animal husbandry and breeding. Moreover, both institutions face the public's naivete about animal life, and accusation about alleged cruelty to animals, often focusing on animal training. Professor Heini Hediger explained animal training from a scientific viewpoint. We can learn from his wisdom, for instance, the theoretical basis on training. Although traditional animal training has received adverse responses in recent years, accomplishments by trainers from the earlier era must be given a proper historical recognition.     

Foraging success under uncertainty: search tradeoffs and optimal space use

Understanding the structural complexity and the main drivers of animal search behaviour is pivotal to foraging ecology. Yet, the role of uncertainty as a generative mechanism of movement patterns is poorly understood. Novel insights from search theory suggest that organisms should collect and assess new information from the environment by producing complex exploratory strategies. Based on an extension of the first passage time theory, and using simple equations and simulations, we unveil the elementary heuristics behind search behaviour. In particular, we show that normal diffusion is not enough for determining optimal exploratory behaviour but anomalous diffusion is required. Searching organisms go through two critical sequential phases (approach and detection) and experience fundamental search tradeoffs that may limit their encounter rates. Using experimental data, we show that biological search includes elements not fully considered in contemporary physical search theory. In particular, the need to consider search movement as a non‐stationary process that brings the organism from one informational state to another. For example, the transition from remaining in an area to departing from it may occur through an exploratory state where cognitive search is challenged. Therefore, a more comprehensive view of foraging ecology requires including current perspectives about movement under uncertainty.