Search

Brown-and-white giant pandas (hereafter brown pandas) are distinct coat color mutants found exclusively in the Qinling Mountains, Shaanxi, China. However, its genetic mechanism has remained unclear since their discovery in 1985. Here, we identified the genetic basis for this coat color variation using a combination of field ecological data, population genomic data, and a CRISPR--Cas9 knockout mouse model. We de novo assembled a long-read-based giant panda genome and resequenced the genomes of 35 giant pandas, including two brown pandas and two family trios associated with a brown panda. We identified a homozygous 25-bp deletion in the first exon of Bace2, a gene encoding amyloid precursor protein cleaving enzyme, as the most likely genetic basis for brown-and-white coat color. This deletion was further validated using PCR and Sanger sequencing of another 192 black giant pandas and CRISPR-Cas9 edited knockout mice. Our investigation revealed that this mutation reduced the number and size of melanosomes of the hairs in knockout mice and possibly in the brown panda, further leading to the hypopigmentation. These findings provide unique insights into the genetic basis of coat color variation in wild animals. [ABSTRACT FROM AUTHOR]

After nearly 30 years of development, China has basically realized the comprehensive conservation of biodiversity. Biodiversity conservation has been upgraded to a national and proposing the "Belt and Road Initiative International Green Development Coalition", China has transformed from an important participant to an active contributor of international agreements. However, there are still problems to be solved and areas for further improvement in biodiversity conservation, such as pursuing quantitative targets while ignoring ecosystem structure and connectivity, insufficient conservation input on marine ecosystem, single source conservation funding mechanism, and non-uniform monitoring data which cannot be effectively integrated and analyzed. In the future, conservation strategies should focus on strengthening top-level design; promoting the synergy between conventions; integrating biodiversity conservation into the territorial and spatial planning, and pollution control; improving quality instead of pursuing quantitative targets; reinforcing marine biodiversity conservation, the construction of wild animal genetic resources bank and field stations, and the research in invasive species and wildlife infectious diseases; and building a big data platform to facilitate the sharing and data mining of biodiversity information. These Chinese wisdom and solutions will contribute to the construction of global ecological civilization. [ABSTRACT FROM AUTHOR]

Attraction to feces in wild mammalian species is extremely rare. Here we introduce the horse manure rolling (HMR) behavior of wild giant pandas (Ailuropoda melanoleuca). Pandas not only frequently sniffed and wallowed in fresh horse manure, but also actively rubbed the fecal matter all over their bodies. The frequency of HMR events was highly correlated with an ambient temperature lower than 15 °C. BCP/BCPO (beta-caryophyllene/caryophyllene oxide) in fresh horse manure was found to drive HMR behavior and attenuated the cold sensitivity of mice by directly targeting and inhibiting transient receptor potential melastatin 8 (TRPM8), an archetypical cold-activated ion channel of mammals. Therefore, horse manure containing BCP/BCPO likely bestows the wild giant pandas with cold tolerance at low ambient temperatures. Together, our study described an unusual behavior, identified BCP/BCPO as chemical inhibitors of TRPM8 ion channel, and provided a plausible chemistry-auxiliary mechanism, in which animals might actively seek and utilize potential chemical resources from their habitat for temperature acclimatization. [ABSTRACT FROM AUTHOR]

Wild giant pandas use different parts of bamboo (shoots, leaves and stems) and different bamboo species at different times of the year. Their usage of bamboo can be classified temporally into a distinct leaf stage, shoot stage and transition stage. An association between this usage pattern and variation in the giant panda gut microbiome remains unknown. Here, we found associations using a gut metagenomic approach and nutritional analyses whereby diversity of the gut microbial community in the leaf and shoot stages was significantly different. Functional metagenomic analysis showed that in the leaf stage, bacteria species over-represented genes involved in raw fibre utilization and cell cycle control. Thus, raw fibre utilization by the gut microbiome was guaranteed during the nutrient-deficient leaf stage by reinforcing gut microbiome robustness. During the protein-abundant shoot stage, the functional capacity of the gut microbiome expanded to include prokaryotic secretion and signal transduction activity, suggesting active interactions between the gut microbiome and host. These results illustrate that seasonal nutrient variation in wild giant pandas substantially influences gut microbiome composition and function. Nutritional interactions between gut microbiomes and hosts appear to be complex and further work is needed. [ABSTRACT FROM AUTHOR]

Phenotypic convergence between distantly related taxa often mirrors adaptation to similar selective pressures and may be driven by genetic convergence. The giant panda (Ailuropoda melanoleuca) and red panda (Ailurus fulgens) belong to different families in the order Carnivora, but both have evolved a specialized bamboo diet and adaptive pseudothumb, representing a classic model of convergent evolution. However, the genetic bases of these morphological and physiological convergences remain unknown. Through de novo sequencing the red panda genome and improving the giant panda genome assembly with added data, we identified genomic signatures of convergent evolution. Limb development genes DYNC2H1 and PCNT have undergone adaptive convergence and may be important candidate genes for pseudothumb development. As evolutionary responses to a bamboo diet, adaptive convergence has occurred in genes involved in the digestion and utilization of bamboo nutrients such as essential amino acids, fatty acids, and vitamins. Similarly, the umami taste receptor gene TAS1R1 has been pseudogenized in both pandas. These findings offer insights into genetic convergence mechanisms underlying phenotypic convergence and adaptation to a specialized bamboo diet. [ABSTRACT FROM AUTHOR]

For any endangered species, our understanding of the spatial variability in its diet across its distribution range, can be important for its conservation. This study focuses on the feeding habitat of the giant panda. For one full year, we surveyed seasonal foraging behaviors of giant pandas (Ailuropoda melanoleuca) in Foping Nature Reserve, China. The results indicated that giant pandas mainly foraged on new shoots of Bashania fargesii and Fargesia qinlingensis in spring and summer, and leaves constituted the major part of their diet in autumn and winter. Stems only marginally occurred in their diet in late winter and early spring. The general pattern in diet composition of giant pandas across mountains reflected the combined consequence of nutrition quality and food availability. Factors affecting foraging-site selection by giant pandas differed across seasons. In spring, they preferred foraging sites closer to trails, with new shoots of B. fargesii higher in basal diameter and less affected by worms. In summer, they foraged at sites with higher density of new shoots and perennial bamboos. Besides overstorey canopy, slope and distance to trails were the other two factors affecting their foragingsite selection in autumn. Temporal variation in diet composition and foraging-site selection exhibited by giant pandas perhaps reflected behaviorally adaptive strategies to changing environmental factors, helping to maximize their energy intake for successful survival and reproduction. Our results, for the first time, support the hypothesized negative effect of some worms on foraging-site selection by giant pandas due to their ingestion of new shoots in spring. Protecting of giant panda foraging sites in these areas where abundant young bamboo resource exist, strengthening management of human activities which can influence giant pandas forage to improve forage habitat quality and widely implementing actions of biological worm pest control during the period when shoot sprouts are eaten can potentially have important implications for habitat conservation for this species. [ABSTRACT FROM AUTHOR]