Population genetic diversity and regional differentiation of Chinese forest frog s (Rana chensinensis) in Heilongjiang Province

The Random Amplified Polymorphism DNA (RAPD) markers were used to stu dy the intra-specific diversity and regional differentiation of the Chinese fore st frogs (Rana chensinensis), which were sampled from the fields of 8 regions in Heilongjiang Province. Totally 78 polymorphic DNA loci were amplified by 10 RAP D primers. By genetic distance analysis and phylogenetic tree reconstruction wit h the Neighbor-Joining (NJ) method the results showed that the populations of Ch inese forest frogs distributed in 8 regions existed great differentiation (Avera ge Fst=0.347, SD=0.235) while there was the paradox between geographic distances and genetic distances. Based on geographic and geological data, a hypothesis wa s posed that it is very possible that the hilly lands in the downstream of the S onghua River and the Heilong River were the center of the origin of the Chinese forest frogs in Heilongjiang Province. And mainly through the Songhua River syst em, the Chinese forest frogs dispersed into the Songneng Plain from the Sanjiang Plain whereas the Fangzheng region became a sub-center for the western dispersi on.

Distribution of Methyl Mercury in Rana chensinensis and Environmental Media in Gold-mining Areas of Upper Reaches of Songhua River,China

The distribution characteristics of methyl mercury in Rana chensinensis and water,sediment and soil in gold-mining areas of the upper reaches of the Songhua River,China were studied by field sampling and laboratory testing.The results show that the methyl mercury contents in water,sediment and soil in gold-mining areas are much higher than those in the control site,indicating that gold-mining activities intensify the methyl mercury pollution in the study area.Methyl mercury contents are in a descending order of sediment > soil > water in the environment,and in a descending order of brain > viscera > muscle > skin in Rana chensinensis.There are significant correlation between methyl mercury contents in Rana chensinensis and those in water and sediment.In particular,the methyl mercury content in the skin of Rana chensinensis is positively correlated with those in water and sediment in spring.Therefore,skin is one of main intake pathways for methyl mercury due to its high permeability.

Differentiations of 5-HT and GAS cells in the digestive canals of Rana chensinensis tadpoles

In the current study, 5-nydroxytryptamine （5-HT） and gastrin （GAS） cells in the digestive canals of Rana chensinensis tadpoles at different developmental stages were investigated by immunohistochemistry. Results showed that the 5-HT cells were only detected in the duodenum before metamorphosis began, and were extensively distributed in the stomach, duodenum, small intestine, and rectum thereafter, with the highest counts found in the duodenum and rectum when metamorphosis was completed. The GAS cells were only distributed in the stomach and duodenum, and only rarely detected in the duodenum before metamorphosis began, but increased in the stomach during metamorphosis and showed zonal distribution in the gastric mucosa when metamorphosis was completed. Metamorphosis is a critical period for amphibians, during which structural and functional physiological adaptations are required to transition from aquatic to terrestrial environments. During metamorphosis, the differentiations of 5-HT cells in the gastrointestinal canals of tadpoles could facilitate mucus secretion regulation, improve digestive canal lubrication, and help water- shortage food digestion in terrestrial environments. Conversely, GAS cell differentiations during metamorphosis might contribute to the digestive and absorptive function transition from herbivore to omnivore.

Histological Architecture of the Nasal Region in Rana chensinensis

The nasal region of Rana chensinensis is divided into the nasal capsules and nasal cavities. In this study, we investigated the adult histological structure of the nasal capsules and nasal cavities in the frog R. chensinensis under the microscope. We found that an eminentia olfactoria is present in this frog and the presence of the eminentia olfactoria may be connected to a terrestrial life style. The double staining method using alcian blue and alizarin red showed that the septomaxilla, the most important bone associated with the olfactory capsules, is an intramembranous bone in R. chensinensis. The opening of the nasolacrimal duct showed a close proximity to the apertura nasalis externa. The presence of the nasolacrimal duct in the olfactory region may be an adaptation to a terrestrial environment. The function of the vomeronasal and olfactory organs is discussed in the paper.

Agro-climatic Division of Rana chensinensis in Fushun

Based on data collected by 3 basic weather stations in Fushun City and 47 automatic weather stations in the whole region,we selected indexes suitable for agro-climatic division of Rana chensinensis,and carried out a study on agro-climatic division of Rana chensinensis in this region.Annual active accumulated temperature ≥10 ℃ and precipitation during April and September are used as basic calculation factors,and we use climatic aridity to make climatic division of Rana chensinensis in Fushun City.According to relevant indexes,we divide Fushun City into 3 regions,namely most appropriate,appropriate and general regions.Finally,countermeasures and suggestions are put forward for providing reference for agricultural production.

A New Brown Frog of the Genus Rana(Anura,Ranidae)from North China,with a Taxonomic Revision of the R.chensinensis Species Group

The Rana chensinensis species group is widely distributed throughout North China.However,its taxonomy and composition remain controversial.In recent field investigations of the Taihang Mountains,a series of Rana specimens were collected,which were once identified as R.chensinensis.However,these samples showed significant differences from R.chensinensis of the type locality(Shaanxi Province in the Qinling Mountains)in both morphology and genetics.In this paper,based on analyses of seventeen geographic populations from the Taihang and Qinling Mountains,we describe a new species(namely R.taihangensis sp.nov.)in the R.chensinensis species group.A phylogenetic analysis of the R.chensinensis species group based on mitochondrial genes—COI,16S rRNA and Cytb—revealed the monophyly of the cryptic species,which formed the sister taxon to R.kukunoris.Morphological comparisons indicated that the cryptic species can be distinguished from its congeners by a combination of characteristics.Additionally,the distribution patterns of the Rana species in North China were clarified.The populations of the southwestern Taihang Mountains,Xiaoqinling Mountains,and Funiu Mountains in Henan Province remain R.chensinensis,whereas the populations recorded as R.chensinensis in Beijing City,Hebei Province,and the southeastern Taihang Mountains of Henan Province should be revised as R.taihangensis sp.nov.

Transcriptome Sequencing and de novo Analysis for Oviductus Ranae of Rana chensinensis Using Illumina RNA-Seq Technology

Oviductus Ranae is the dried oviduct of female Rana tem-poraria chensinensis （David）, distributed mainly in North- eastern China. Oviductus Ranae is one of the best-known and highly valued oriental foods and medicines. Traditional Chinese medicine holds that Oviductus Ranae can nourish yin, moisten lung and replenish the kidney essence. Meanwhile, activities of Oviductus Ranae such as anti-aging, anti-lipemic, anti-oxidation and anti-fatigue have also been demonstrated by modern phar-macological studies. Previous studies have shown that Oviductus Ranae is mainly composed of proteins, which are up to 50% or more.