Consuming Different Structural Parts of Bamboo Induce Gut Microbiome Changes in Captive Giant Pandas.

Giant pandas consume different structural parts of bamboo (shoots, leaves and culms) during different seasons. Previous research showed different bamboo parts have varying nutritional content and that a long-term diet consisting of a single part of bamboo resulted in remarkable metabolic changes within captive giant pandas. However, the effects on the gut microbiome of giant pandas, as a result of a single bamboo part diet, have not been investigated. Here, we evaluated the changes in gut microbial communities based on single bamboo part diets and their potential implications by using 16S rRNA gene-based amplicon sequencing and metagenome shotgun sequencing. We found that the composition and function of the gut microbiome from captive giant pandas fed exclusively culms were significantly different from that of individuals fed shoots or leaves. During the culm feeding period, the gut microbiome showed strongest digestive capabilities for cellulose, hemicellulose and starch, and had the highest potential abilities for the biosynthesis of bile acids, fatty acids and amino acids. This suggests the microbiome aids in breaking down culm, which is more difficult for giant pandas to digest, as a means to compensate for the nutrient poor content of the culm. Genes related to fatty acid metabolism and tricarboxylic acid cycle enzymes were more abundant during the leaf stage diet than that in the shoot and culm stages. Thus, the microbiome may help giant pandas, which typically have low lipase levels, with fat digestion. These results illustrate that adaptive changes in the gut microbiome community and function may be an important mechanism to aid giant panda digestion when consuming different structural parts of bamboo.

Climate change and landscape-use patterns influence recent past distribution of giant pandas.

Climate change is one of the most pervasive threats to biodiversity globally, yet the influence of climate relative to other drivers of species depletion and range contraction remain difficult to disentangle. Here, we examine climatic and non-climatic correlates of giant panda (Ailuropoda melanoleuca) distribution using a large-scale 30 year dataset to evaluate whether a changing climate has already influenced panda distribution. We document several climatic patterns, including increasing temperatures, and alterations to seasonal temperature and precipitation. We found that while climatic factors were the most influential predictors of panda distribution, their importance diminished over time, while landscape variables have become relatively more influential. We conclude that the panda's distribution has been influenced by changing climate, but conservation intervention to manage habitat is working to increasingly offset these negative consequences.

Effects of aflatoxin B1 on oxidative stress markers and apoptosis of spleens in broilers.

The purpose of the present study was to investigate the oxidative damage and apoptosis induced by aflatoxin B1 (AFB1) in spleen of broilers. A total of 200 one-day-old avian male broilers were randomly divided into 4 equal groups of 50 each and were fed for 21 days as follows: a control diet and three AFB1 diets containing 0.15, 0.3, and 0.6 mg AFB1/kg diet. Consumption of AFB1 diets induced oxidative stress in the spleen of chicken as evidenced by reduced glutathione peroxidase, glutathione reductase, and catalase activities, decreased glutathione contents, and increased malondialdehyde contents in explaining the pathogenesis. Flow cytometer method and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling assay revealed that the apoptotic splenocytes were increased in AFB1 groups. The results suggest that AFB1 induced excessive apoptosis of splenic lymphocytes, which is correlated with increased oxidative stress. The present results may be helpful for explaining the pathogenesis of AFB1-induced immunosuppression.

Zinc and Inflammatory Bowel Disease: From Clinical Study to Animal Experiment.

Inflammatory bowel disease (IBD) is a chronic inflammatory disease of the gastrointestinal tract (GI) with a high incidence rate globally, and IBD patients are often accompanied by zinc deficiency. This review aims to summarize the potential therapeutic value of zinc supplementation in IBD clinical patients and animal models. Zinc supplementation can relieve the severity of IBD especially in patients with zinc deficiency. The clinical severity of IBD were mainly evaluated through some scoring methods involving clinical performance, endoscopic observation, blood biochemistry, and pathologic biopsy. Through conducting animal experiments, it has been found that zinc plays an important role in alleviating clinical symptoms and improving pathological lesions. In both clinical observation and animal experiment of IBD, the therapeutic mechanisms of zinc interventions have been found to be related to immunomodulation, intestinal epithelial repair, and gut microbiota's balance. Furthermore, the antioxidant activity of zinc was clarified in animal experiment. Appropriate zinc supplementation is beneficial for IBD therapy, and the present evidence highlights that alleviating zinc-deficient status can effectively improve the severity of clinical symptoms in IBD patients and animal models.

Chitosan supplementation reduces oxidative stress in Leiothrix lutea in acute heat stress.

In order to assess the effects of chitosan supplementation on immune function, antioxidant enzyme activities and histological changes in Leiothrix lutea exposed to acute heat stress, 80 healthy adult birds were randomly divided into five experimental groups. The normal-temperature group (NTG) was maintained at 21°C and fed the basic diet. The treatment groups were fed the basic diet supplemented with 0%, 0.1%, 0.5% and 1.0% chitosan, respectively, in normal-temperature environment for 30 days and then exposed to heat (35°C and 40% relative humidity) for 3 hr. The results showed that the immune function and anti-oxidative enzyme activities in L. lutea in heat-stressed environment were enhanced by chitosan supplementation, whereas oxidative damage of tissues and cells were alleviated. The results revealed that addition of 0.5% chitosan to the diet may be optimal, playing a key role in meeting the demands of captive-bred L. lutea in high-temperature environments. This may constitute a useful feeding strategy in accordance with the behavioural selection of wild L. lutea, and could effectively promote ex situ conservation.

Assessing the Effectiveness of China's Panda Protection System.

Protected areas form the backbone of biodiversity conservation, yet their effectiveness is often not known nor even evaluated [1-3]. China-best known for its record of ecological degradation in the face of rapidly increasing gross domestic product and resource consumption [4]-has in recent years enacted a series of policies and programs to conserve its natural resources. Chief among them is an ambitious protected area system covering 17% of its terrestrial land mass [4, 5]. An important early impetus for the establishment of this reserve system was the protection of the giant panda (Ailuropoda melanoleuca) [5-8]. Using data from two previous large-scale surveys [9, 10] separated by a decade, and including over 50,000 habitat plots, we examined the panda population and habitat trends inside and outside reserves. Despite ambitious ecocompensation programs in panda habitat outside reserves [11-13], the protection provided by reserves reduced most classes of human disturbance compared to outside reserves, and most disturbances decreased through time more strongly inside than outside reserves. Reserves also contained more and increasing suitable panda than found outside reserves [14, 15]. Comparing reserve performance, reserves with increasing older forests and bamboo correlated with increasing panda populations. Together these findings indicate that China's panda reserves have been effective and that they are functioning better over time, conserving more and better habitats and containing more pandas. While China's protected area system still has much room for improvement [4, 5], including to support pandas [16], these findings underscore the progress made in China's nascent environmental movement.

A Diet Diverse in Bamboo Parts is Important for Giant Panda (Ailuropoda melanoleuca) Metabolism and Health.

The aim of this study was to determine the metabolic response in giant pandas (Ailuropoda melanoleuca) to the consumption of certain parts of bamboo above ground growth. Giant pandas were provisioned with three species of bamboo: Phyllostachys bissetii, of which they only consume the culm (culm group); Bashania fargesii, of which they only consume the leaves (leaf group); and Qiongzhuea opienensis, of which they only consume the shoots (shoot group). The "culm" group absorbed the highest amount of calories and fiber, but was in short energy supply (depressed tricarboxylic acid cycle activity), and high fiber level diet might reduce the digestibility of protein. The "culm" and "leaf" groups absorbed less protein, and had a lower rate of body mass growth than the "shoot" group. Digestion of fiber requires energy input and yields low caloric extraction from the culm and leaf, and protein intake is important for increasing body mass. However, long-term consumption of shoots may have a potentially negative effect on the health because of high protein composition. Therefore, a balanced diet consisting of diverse plant parts of bamboo is important for the overall metabolic function and health of captive giant pandas.

Histomorphological structure of the Bursa cloacalis (Bursa of Fabricius) in young Leiothrix lutea: a comparative study using light microscopy and transmission electron microscopy / Estructura histomorfológica de la Bursa cloacalis (Bursa de Fabricius) en jóvenes Leiothrix lutea: un estudio comparativo utilizando microscopía óptica y microscopía electrónica de transmisión

SUMMARY: This study aimed to investigate the microstructure and ultrastructure of the Bursa cloacalis (Bursa of Fabricius) (BC) in young Leiothrix lutea at various days of age (a few days after hatching) using light microscopy and transmission electron microscopy. The bird BC was sampled at 1, 5, 7, and 9 days of age. Immediately after dissection, the structure and integrity of the BC (not degenerative) were retained and the specific temporal features could be visualized precisely. After hematoxylin-eosin staining and uranyl acetate/lead citrate staining, the microstructure and ultrastructure of the BC, respectively, could be observed clearly. The microscopic observations revealed the following: in addition to change in the size of BC or lymphoid follicles, many cavities were found in the BC; the distribution of the lymphoid follicles in Leiothrix lutea was different from that in other birds; and the segregating line between the bursal cortex and medulla became increasingly clear as the age increased. In conclusion, the structural data obtained in this study provides a better understanding of the specific immunological function of the BC in Leiothrix lutea.

RESUMEN: Este estudio tuvo como objetivo investigar la microestructura y ultraestructura de la Bursa cloacalis (BC) en Leiothrix lutea joven unos días después de la eclosión, utilizando microscopía óptica y microscopía electrónica de transmisión. La BC se muestreó a los 1, 5, 7 y 9 días de edad del Leiothrix lutea. Inmediatamente después de la disección, se observó la estructura y la integridad de la CB (no degenerativa) y se pudo visualizar con precisión las características temporales específicas. Después de la tinción con hematoxilina-eosina y con acetato de uranilo /citrato de plomo, pudimos observar claramente la microestructura y ultraestructura de la BC. Las observaciones microscópicas revelaron el cambio en el tamaño de la CB o de los folículos linfoides y además, se encontraron numerosas cavidades en la CB; la distribución de los folículos linfoides en Leiothrix lutea era diferente a la de otras aves; y la línea de segregación entre la corteza bursal y la médula se hizo cada vez más clara a medida que aumentaba la edad. En conclusión, los datos estructurales obtenidos en este estudio proporcionan una mejor comprensión de la función inmunológica específica de la Bursa cloacalis en Leiothrix lutea.

The mitochondrial and endoplasmic reticulum pathways involved in the apoptosis of bursa of Fabricius cells in broilers exposed to dietary aflatoxin B1.

Aflatoxin B1 (AFB1), a toxic metabolite produced by some fungi, exerts well-known hepatocarcinogenic and immunosuppressive effects, the latter can increase the apoptotic immune cells in vitro. However, it is largely unknown that which signaling pathways contribute to excessive apoptosis of immune cells which induced by AFB1. In this study, we investigated the roles of the mitochondria, endoplasmic reticulum (ER) and death receptor activated apoptotic pathways in the bursal of Fabricius (BF) cells in the broilers exposed to AFB1 diet. We found that (1) AFB1 diet induced morphological changes in the BF. (2) FCM and TUNEL methods showed that excessive apoptosis could be resulted from AFB1 intake. (3) AFB1-induced apoptosis of bursal cells involved mitochondrial pathway (increase of Bax, Bak, cytC, caspase-9, Apaf-1, caspase-3 and decrease of Bcl-2 and Bcl-xL) and ER pathway (increase of Grp78/Bip, Grp94 and CaM). (4) Oxidative stress was confirmed in the BF of chicken fed on AFB1 diet. Overall, this work is the first to demonstrate that the activation of mitochondria and ER apoptosis pathways can lead to excessive apoptosis in BF cells, and oxidative stress is a crucial driver during AFB1 exposure.

Comparison of microhabitats and foraging strategies between the captive-born Zhangxiang and wild giant pandas: implications for future reintroduction.

The female giant panda Zhangxiang (pedigree number 826) was born on August 20, 2011 in Wolong Nature Reserve, China. On November 6, 2013, Zhangxiang was transported into the acclimatization enclosure in the Liziping Nature Reserve. Before Zhangxiang left the enclosure into the wild, we conducted the first study to compare microhabitats and foraging strategies between Zhangxiang in the enclosure and giant pandas in the wild. Compared with the latter, microhabitats of Zhangxiang in the enclosure are characteristic of gentler slope, more trees, higher canopy, smaller tree DBH, and lower density of living bamboos. Diet composition and foraging behaviors significantly differed between Zhangxiang and wild giant pandas, perhaps reflecting the combined consequence of environmental conditions (e.g., bamboo species) and individual status (e.g., age, mastication ability, etc.). The difference in microhabitats and foraging strategies between Zhangxiang and wild giant pandas implied that after being released into the natural habitat in the reserve, Zhangxiang will have to adapt to the environmental conditions once again. For future reintroduction, the enclosure can be extended to the Bashania spanostachya forest in the reserve, and captive giant pandas for release can thus normally transit into the wild without human intervention during acclimatization period. For other acclimatization enclosures to be constructed in the future, ecological environment inside, including topography, forests, and bamboos as well, should as possible as can match the habitat that the giant panda to-be-reinforced populations inhabit.

The Lushan earthquake and the giant panda: impacts and conservation.

Earthquakes not only result in a great loss of human life and property, but also have profound effects on the Earth's biodiversity. The Lushan earthquake occurred on 20 Apr 2013, with a magnitude of 7.0 and an intensity of 9.0 degrees. A distance of 17.0 km from its epicenter to the nearest distribution site of giant pandas recorded in the Third National Survey was determined. Making use of research on the Wenchuan earthquake (with a magnitude of 8.0), which occurred approximately 5 years ago, we briefly analyze the impacts of the Lushan earthquake on giant pandas and their habitat. An earthquake may interrupt ongoing behaviors of giant pandas and may also cause injury or death. In addition, an earthquake can damage conservation facilities for pandas, and result in further habitat fragmentation and degradation. However, from a historical point of view, the impacts of human activities on giant pandas and their habitat may, in fact, far outweigh those of natural disasters such as earthquakes. Measures taken to promote habitat restoration and conservation network reconstruction in earthquake-affected areas should be based on requirements of giant pandas, not those of humans.

Effects of sodium selenite on the decreased percentage of T cell subsets, contents of serum IL-2 and IFN-γ induced by aflatoxin B1 in broilers.

Aflatoxin B1 (AFB1), especially inducing hepatocellular carcinoma and immunosuppression of animals, poses a serious healthy and economic hazard to both humans and livestock. Animal studies have demonstrated that selenium (Se) provides anticarcinogenic and antimutagenic effects against AFB1. However, the effects of Se against AFB1-induced immunosuppression were rarely reported. To test this, three hundred 1-day-old male avian broilers were divided into five groups and fed on control diet (0.4 mg/kg Se), AFB1 group(0.3mg/kg AFB1+0.4 mg/kg Se), AFB1+Se group I(0.3mg/kg AFB1+0.6 mg/kg Se), AFB1+Se group II(0.3mg/kg AFB1+0.8 mg/kg Se) and AFB1+Se group III(0.3mg/kg AFB1+1.0mg/kg Se) for 21 days (n=60/group). Although the body weight in AFB1 group was lower than that in control group at 14 days of age, there no significant differences on body weight among five groups at 7 and 21 days of age. No evident clinical symptoms were observed among five groups from 7 to 21 days of age. The percentages of peripheral blood CD3(+), CD3(+)CD4(+), CD3(+)CD8(+) and the contents of serum IL-2 and IFN-γ in AFB1 group were decreased, compared with those in control group. Compared with those in AFB1 group, the percentages of CD3(+), CD3(+)CD4(+) and CD3(+)CD8(+) T cells in three AFB1+Se groups were increased from 14 to 21 days of age, and the contents of serum IL-2 and IFN-γ in all AFB1+Se groups were increased from 7 to 21 days of age. On the contrary, the percentages of CD3(+), CD3(+)CD4(+) and CD3(+)CD8(+) T cells, and the contents of Serum IL-2 and IFN-γ in AFB1+Se group III were lower than those in AFB1+Se group II. It was concluded that 0.6 and 0.8 mg/kg Se could increase the decreased percentages of peripheral blood T-cell subsets and the contents of serum IL-2 and IFN-γ induced by 0.3mg/kg AFB1 in the diets, and cellular immune function could be improved in chickens.