Thesis (Ph.D.)--George Mason University, 2008. / Vita: p. 180. Thesis director: Thomas C. Wood. Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Environmental Science and Public Policy. Title from PDF t.p. (viewed Mar. 17, 2009). Includes bibliographical references (p. 156-179). Also issued in print.

Thesis (M.S. in Psych.)--School of Psychology, Georgia Institute of Technology, 2004. Directed by Terry Maple. / Includes bibliographical references (leaves 58-69).

Giant pandas are unique animals because of their digestive system is similar to carnivores but they have in fact adapted to a plant diet with bamboo as their main food source. According to fossils records, giant pandas were omnivorous approximately 7 million years ago, becoming almost vegetarian after 4.6 to 5 million years of evolution. However, their genome and anatomical structure do not favor bamboo digestion. For more than a decade, researchers have been questioning the underlying mechanism of their ability to digest bamboo. In 2010, the genome of giant panda was completed, which confirmed that their genome had no gene encoding for cellulolytic enzymes. Thus, the gut microbiota of giant panda, which has been hypothesized to play a key role in bamboo digestion, has garnered unprecedented attention. Researchers are also interested in the giant panda’s gut microbes due to their potential application in biomass conversion. In Chapters 2 and 3 of this thesis, the microbial catalog of the giant panda’s gut microbiota was characterized, showing possible age-related microbial dysbiosis. Moreover, the microbiota, both bacterial and fungal was highly individualized because very few operational taxonomic units were shared among the four pandas in this study. Novel homoacetogens were also identified in the giant panda using functional gene clone-library sequencing. Using metagenomic sequencing, I uncovered the first evidence of human and animal related viruses in the giant panda’s gut. In addition to the community structure, I also determined the metabolic pathways of the microbiome. From KEGG annotation, a metabolic pathway for both cellulose and hemicellulose metabolism was identified. Comparative metagenomic analysis indicated that the giant panda’s gut microbiome was taxonomically and functionally distinct from those in mammals. In Chapters 4 and 5, a total of 97 species of bacteria were isolated and identified using biochemical assays. Four of these bacteria showed powerful cellulolytic and hemicellulolytic activities on solid media. The gram-positive bacteria (HKUOP_BS) and the gram-negative bacteria (HKUOP_A14) were found to be rod shaped, facultative anaerobes that had the ability to powerfully hydrolyze both cellulose and hemicellulose using intracellular and extracellular enzymes respectively. In Chapter 6, I determined the complete genome of a cellulolytic bacterium, Klebsiella oxytoca HKUOPL1, from giant panda and further described the annotated virulence, drug resistant, functional and potential horizontal transferring genes. The phylogenomic tree indicated that K. oxytoca HKUOPL1 closely resembled the K. oxytoca KCTC 1686 strain commonly used in 2,3-butanediol production. In captive giant pandas, a mucous excretion episode usually occurs with mild to severe colic. To understand the host-microbial interactions during this episode, bacterial communities were compared between mucous excreta and normal feces. The shifts in community abundance (especially flooding of Clostridia) may be associated with the mucous excretion episode. This study provides a better understanding of the microbial community structure and function in the giant panda’s gut. / published_or_final_version / Biological Sciences / Doctoral / Doctor of Philosophy

Preservation of giant pandas, Ailuropoda melanoleuca, is a worldwide concern. This study was designed to examine dietary and reproductive challenges associated with panda management. Phytoestrogens are natural plant compounds that mimic estrogen and often negatively impact mammalian reproduction. Phytoestrogens in bamboo, the panda’s primary food source, is unknown. Here, estrogen radioimmuno- and receptor-binding assays revealed estrogenic activity in three species of Phyllostachys bamboo. These results present indirect evidence of phytoestrogenic mimics in bamboo, but their relevance is still unknown. Studies were also conducted to observe panda reproductive behaviors in an attempt to augment the use of an artificial vagina (AV) for semen collection. A preliminary study confirmed the panda could differentiate between estrus urine and a water ‘control.’ However, when estrus urine was placed on the AV as an attractant, the subject didn’t approach the AV. Further investigation of dietary challenges and reproductive alternatives are needed to substantiate these findings.

The objective of this study was to develop near infrared reflectance spectroscopy (NIRS) calibration equations from bamboo and fecal samples to predict diet composition and the physiological status of giant pandas. Discrimination between branch, culm, and leaf parts of bamboo resulted in an Rsquare (R2) of 0.88. The calibration equation for discriminating between 4 species of bamboo had an R2 of 0.47. Calibration equations were created for all bamboo species combined to determine the ability of NIRS to predict the nutrient constituents of CP, NDF, ADF, DM, and OM. No R2 was lower than 0.96, with the exception of DM at 0.63, which was consistently difficult to accurately predict due to variation in factors relating to difference in location of lab work (humidity, shipping, methods, etc.). Giant panda diets vary between seasons from eating primarily leaf to eating almost only culm. When bamboo part samples were compared between March and October, all resulting R2s were above 0.80. The sensitivity analyses for leaf and culm samples within diet season produced inconclusive results, but sensitivity analyses for fecal samples yielded an ability to more greatly discriminate between months that were further apart. For giant panda physiological status calibrations, fecal samples were collected from the Memphis Zoo, Smithsonian's National Zoo, Zoo Atlanta, and San Diego Zoo from 2006 to 2007. One-hundred fecal spectra were used to develop discriminant equations with which to predict between adults and juveniles. The resulting calibration was 100% correct for both age classes. Predictions between 252 male and female fecal spectra were 89% correct for females and 90% correct for males. A small number of samples (N= 60) were used to create a discriminant equation to differentiate between pregnant and non pregnant females. The exercise resulted in an R2 of 0.68 and a prediction of 100% for both pregnant and not-pregnant. It has been determined through these studies that NIRS has the potential to determine nutrient composition of bamboo and giant panda fecals, but increased sampling and equation development is needed before these calibrations are applicable in a captive or wild giant panda setting.

No description available.

No description available.

The giant panda (Ailuropoda melanoleuca) is an endangered species and many efforts are being made to ensure its survival, including numerous research studies. However, there has been little investigation of spatial memory in the giant panda. Spatial memory is an important mechanism for survival in the wild, allowing an animal to find and remember the location of food, mates, den sites and avoid predators. Memory assessment in non-human species typically involves the use of recognition, as opposed to recall tasks. The current study tested spatial memory recall in 1.1 giant pandas using a delayed response memory task. The design required a delayed response to a previously lighted location, with varying lengths of delay between the observation phase and the test phase. The male subject reached criterion at 2-, 3-, 4-, 5-, 6-, and 10-second delays. The female subject reached criterion at 2-, 3-, 4-, 5-, 6-, 10-, and 15-second delays. The results support the hypothesis that giant pandas have working memory recall ability for spatial location.

The present study examined the relationship between early rearing experience and reproductive competence in captive adult giant pandas (Ailuropoda melanoleuca) and spectacled bears (Tremarctos ornatus). Life history information of 52 giant pandas and 34 spectacled bears were obtained from the International Studbook and by interviewing staff at institutions housing the subjects. The early rearing experience variables included duration of mother rearing, social access within 1-yr period following maternal separation, and birth origin. Correlation, Chi-square, and logistic regression analyses were used to analyze the data. Contrary to findings from studies with other animals, the results generally suggest that early rearing experience is not related to adult reproductive success in giant pandas and spectacled bears. Alternative explanation and limitation of the study were discussed; suggestions were made for future study.

Thesis (Ph. D.)--Psychology, Georgia Institute of Technology, 2006. / Terry Maple, Committee Chair ; M. Jackson Marr, Committee Member ; Rebecca Snyder, Committee Member ; Marc Weissburg, Committee Member ; Paul Corballis, Committee Member ; Roger Bakeman, Committee Member.