title: Evolutionary and functional novelty of pancreatic ribonuclease: a study of Musteloidea (order Carnivora).
abstract: Pancreatic ribonuclease (RNASE1) is a digestive enzyme that has been one of the key models in studies of evolutionary innovation and functional diversification. It has been believed that the RNASE1 gene duplications are correlated with the plant-feeding adaptation of foregut-fermenting herbivores. Here, we characterized RNASE1 genes from Caniformia, which has a simple digestive system and lacks microbial digestion typical of herbivores, in an unprecedented scope based on both gene sequence and tissue expression analyses. Remarkably, the results yielded new hypotheses regarding the evolution and the function of Caniformia RNASE1 genes. Four independent gene duplication events in the families of superfamily Musteloidea, including Procyonidae, Ailuridae, Mephitidae and Mustelidae, were recovered, rejecting previous Mustelidae-specific duplication hypothesis, but supporting Musteloidea duplication hypothesis. Moreover, our analyses revealed pronounced differences among the RNASE1 gene copies regarding their selection pressures, pI values and tissue expression patterns, suggesting the differences in their physiological functions. Notably, the expression analyses detected the transcription of a RNASE1 pseudogene in several tissues, raising the possibility that pseudogenes are also a potential source during the RNase functional diversification. In sum, the present work demonstrated a far more complex and intriguing evolutionary pattern and functional diversity of mammalian ribonuclease than previously thought.
authors.affiliation: Laboratory for Conservation and Utilization of Bio-resource & Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming 650091, PR China.
authors.forename: Jiang
authors.initials: J
authors.lastname: Liu
authors.affiliation: Laboratory for Conservation and Utilization of Bio-resource & Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming 650091, PR China.
authors.forename: Xiao-ping
authors.initials: XP
authors.lastname: Wang
authors.affiliation: Department of Biology, Creighton University, Omaha, Nebraska, United States of America.
authors.forename: Soochin
authors.initials: S
authors.lastname: Cho
authors.affiliation: Department of Natural History, Royal Ontario Museum, 100 Queen's Park, Toronto, Ontario M5S 2C6, Canada (BKL).
authors.forename: Burton K
authors.initials: BK
authors.lastname: Lim
authors.affiliation: Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada.
authors.forename: David M
authors.initials: DM
authors.lastname: Irwin
authors.affiliation: San Diego Zoo Institute for Conservation Research, 15600 San Pasqual Valley Road, Escondido, CA 92027 USA.
authors.forename: Oliver A
authors.initials: OA
authors.lastname: Ryder
authors.affiliation: State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China.
authors.forename: Ya-ping
authors.initials: YP
authors.lastname: Zhang
authors.affiliation: 1] Laboratory for Conservation and Utilization of Bio-resource & Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming 650091, PR China [2] Key Laboratory for Animal Genetic Diversity and Evolution of High Education in Yunnan Province, Yunnan University, Kunming, Yunnan 650091, China.
authors.forename: Li
authors.initials: L
authors.lastname: Yu
mesh_terms: D000818:Animals; D002335:Carnivora; D019143:Evolution, Molecular; D008322:Mammals; D045969:Mustelidae / Q000235:genetics*; D010802:Phylogeny; D012259:Ribonuclease, Pancreatic / Q000235:genetics* / Q000378:metabolism
chemical_list: D012259:Ribonuclease, Pancreatic