We describe a new species of the genus Tylototriton from Ingyin Taung Mt., Mohnyin Township, Kachin State, Myanmar, based on morphological and molecular evidence. The new species is assigned to the subgenus Tylototriton s. str. and is clearly distinct from all known congeners by the following characters: medium body size; thin, long tail, lacking lateral grooves; rough skin; truncate snout; wide, protruding supratemporal bony ridges on head, beginning at anterior corner of orbit; weak, almost indistinct sagittal ridge; long, thin limbs, broadly overlapping when adpressed along body; distinct, wide, non-segmented vertebral ridge; 13 or 14 rib nodules; brown to darkbrown background coloration with dull orange-brown to yellowish-brown markings on labial regions, parotoids, rib nodules, whole limbs, vent, and ventral tail ridge. We also briefly discuss biogeography and species diversity of thegenus Tylototriton in Myanmar.
Gibbons and siamangs (Hylobatidae) are well-known for their rapid chromosomal evolution, which has resulted in high speciation rate within the family. On the other hand, distinct karyotypes do not prevent speciation, allowing interbreeding between individuals in captivity, and the unwanted hybrids are ethically problematic as all gibbon species are endangered or critically endangered. Thus, accurate species identification is crucial for captive breeding, particularly in China where studbooks are unavailable. Identification based on external morphology is difficult, especially for hybrids, because species are usually similar in appearance. In this study, we employed G-banding karyotyping and fluorescence in situ hybridization (FISH) as well as a PCR-based approach to examine karyotypic characteristics and identify crested gibbons of the genus Nomascus from zoos and nature reserves in China. We characterized and identified five karyotypes from 21 individuals of Nomascus. Using karyotypes and mitochondrial and nuclear genes, we identified three purebred species and three hybrids, including one F2 hybrid between N. gabriellae and N. siki. Our results also supported that N. leucogenys and N. siki shared the same inversion on chromosome 7, which resolves arguments from previous studies. Our results demonstrated that both karyotyping and DNA-based approaches were suitable for identifying purebred species, though neither was ideal for hybrid identification. The advantages and disadvantages of both approaches are discussed. Our results further highlight the importance of animal ethics and welfare, which are critical for endangered species in captivity.
Studies on behavioral flexibility in response to habitat differences and degradation are crucial for developing conservation strategies for endangered species. Trachypithecus species inhabit various habitats and display different patterns of strata use; however, the effect of habitat structure on strata use remains poorly studied. Here, we investigated strata use patterns of Indo-Chinese gray langurs (Trachypithecus crepusculus) in a primary evergreen forest in Mt. Wuliang, southwest China, from June 2012 to January 2016. In addition, we compared T. crepusculus strata use and terrestriality with five other Trachypithecus species from previous studies. Unlike langurs living in karst forests, our study group was typically arboreal and spent only 2.9% of time on the ground. The group showed a preference for higher strata when resting and lower strata (<20 m) when moving. The langurs primarily used time on the ground for geophagy, but otherwise avoided the ground during feeding. These strata use patterns are similar to those of limestone langurs (T. francoisi) when using continuous forests. At the genus level (n=6 species), we found a negative relationship between habitat forest cover and terrestriality. This negative relationship was also true for the five limestone langur species, implying limestone langurs increase territoriality in response to decreased forest cover. Our results document behavioral flexibility in strata use of Trachypithecus langurs and highlight the importance of the protection of continuous forests to promote langur conservation.
Adult male tree shrews vigorously defend against intruding male conspecifics. However, the characteristics of social behavior have not been entirely explored in these males. In this study, male wild-type tree shrews (Tupaia belangeri chinensis) and C57BL/6J mice were first allowed to familiarize themselves with an open-field apparatus. The tree shrews exhibited a short duration of movement (moving) in the novel environment, whereas the mice exhibited a long duration of movement. In the 30 min social preference-avoidance test, target animals significantly decreased the time spent by the experimental tree shrews in the social interaction (SI) zone, whereas experimental male mice exhibited the opposite. In addition, experimental tree shrews displayed a significantly longer latency to enter the SI zone in the second 15 min session (target-present) than in the first 15 min session (target-absent), which was different from that found in mice. Distinct behavioral patterns in response to a conspecific male were also observed in male tree shrews and mice in the first, second, and third 5 min periods. Thus, social behaviors in tree shrews and mice appeared to be time dependent. In summary, our study provides results of a modified social preference-avoidance test designed for the assessment of social behavior in tree shrews. Our findings demonstrate the existence of social avoidance behavior in male tree shrews and prosocial behavior in male mice toward unfamiliar conspecifics. The tree shrew may be a new animal model, which differs from mice, for the study of social avoidance and prosocial behaviors.
This study describes a new blind barbine fish species, Sinocyclocheilus anshuiensis sp. nov. discovered based on five specimens collected from a cave in Luolou town, Lingyun County, Guangxi, China, in June and July 2012. Sinocyclocheilus anshuiensis is distinguished from other species of Sinocyclocheilus by having the following combination of characteristics: dorsal fin with 7 branched rays, last unbranched dorsal-fin ray weak with serrations on posterior edge of its lower part; pelvic-fin origin anterior to dorsal-fin origin; dorsal profile of head sharply uplift, a forward flesh tuber present on frontal; body covered with scales, and lateral line with 34-38 scales, lateral line scales are as big as their neighbor scales; caudal peduncle with developed fresh crests.
Copulation patterns are important to understanding male mating strategies and stabilization strategies of social organizations in primates. However, information on copulation patterns of Asian primates is relatively rare. This study was undertaken to collect data on mating behavior and birth seasonality of Black-and-white Snub-nosed monkeys ( Rhinopithecus bieti ) using all occurrence sampling and Focal animal-scan sampling methods at Mt. Lasha, between January and December, 2011. Our study focused on observing mating frequency and birth rates. Snub-nosed monkeys mate year round, with two observable peaks: one reproductive peak during the mating season, roughly from August to October, and a second non-breeding peak during the birth season. It is unclear what biological significance this non-reproductive mating peak has. During our observation, we noted a lower ratio of mount to ejaculation and rare ejaculatory copulations, which indicated that every mating would not result in ejaculation. This study corroborates the previous view that the Rhinopithecus bieti's copulatory pattern is likely multiple-mount ejaculation (MME) or at the upper part of mating continuum of single-mount ejaculation (SME) toward MME. More ejaculatory copulations initiated by males than females indicate that MME is not only a mating strategy of males, but that males can influence the position of their copulatory pattern on the continuum between SME and MME. The mating frequencies significantly correlated with the birth rates with a delay of 6 to 7 months. Monkeys gave birth within a strict seasonality with a birth peak of March, which confirms the previous view. Infants were born with a certain degree of synchronization, but different populations displayed different modes of synchronizations.
Peptidoglycan recognition proteins (PGRPs) are a family of pattern recognition receptors (PRRs) of the immune system, which bind and hydrolyze bacterial peptidoglycan. Here, a long type PGRP (PGRP-L) was first cloned in the lower vertebrate species Xenopus tropicalis (Xt). The XtPGRP-L possessed a conserved genomic structure with five exons and four introns. The alignment and phylogenetic analysis indicated that XtPGRP-L might be a type of amidase-like PGRP. The 3-D model showed that XtPGRP-L possessed a conserved structure compared with the Drosophila PGRP-Lb. During embryonic development, XtPGRP-L was not expressed until the 72 h tadpole stage. In adult tissues, it was strongly expressed in the liver, lung, intestine, and stomach. Furthermore, after LPS stimulation, the expression of XtPGRP-L was up-regulated significantly in the liver, intestine and spleen, indicating that XtPGRP-L may play an important role in the innate immunity of Xenopus tropicalis.
Phrynocephalus przewalskii is one kind of lizards inhabiting inclusively in the desert that has controversial viewpoints on its phylogeny. Based on mitochondrial ND2 gene of 119 samples from 12 geographic populations, we analyzed the effects of environmental factors on the variation of genetic diversity, as well as its relationship to P. versicolor . The results showed that these populations clustered into three major lineages, with P. versicolor embedded within one lineage. The twelve populations had great genetic diversity variation, which was tightly linked with local altitude, annual precipitation, and variation of annual precipitation. High latitudes, increased annual precipitation and great variation in annual precipitations may all have resulted in the decrease of genetic diversity. It thus assumed that altitude can change the genetic diversity of different geographic populations of P. przewalskii resulting from the effects of different local annual precipitation.
One specimen was collected from the main course of Lancangjiang River (upper reach of Mekong) in Guanlei Port, Xishuangbanna, Yunnan, China in April, 2008. It is identified as Dasyatis laosensis, a new record of Dasyatidae species in China. It could be distinguished from other Dasyatis species by a combination of the following characteristics: one enlarged venomous spine on the tail, ventral surface of body with orange marginal coloration, tail length greater than body length.
The aim of this study was to establish a method of isolating and culturing smooth muscle cells from the ductus deferens of rats. Smooth muscle cells were prepared from ductus deferens by explanting technique after dissection of adventitia and intimae, and cultured in vitro. The identification of the smooth muscle cells were verified by using anti α-smooth muscle actin (α-SMA) immunohistochemistry studies. The result suggested that the cells are multi-morphous, showing long fusiform or star shapes. The apophysis of cells contacted and coalesced to each other, in some regions the cells overlapped in multilayer, while in the other regions they formed monolayer that fluctuated and showed a "peak-valley" shape. They presented a positive reaction through immunohistochemistry studies. The purity of the cells was more than 99% through this method. The culturing of smooth muscle cells by explanting technique is simple and stable.
Postnatal developments of morphological features (forearm and body mass) and vocalization (call frequencies and durations) of Rhinolophuspusillus were studied in the Jishui Cave of Guilin City from May 31st to July 20th 2006. The morphological changes indicated that infants of R. pusillus grew significantly in the postnatal three weeks and then gradually slowed down. Both forearm length and body weight were significantly correlated with the growing of age. Durations of infants' calls were fairly variable and longer than those of adults. No significant correlation was found between the duration and age. Spectral characteristics indicated that the calls produced by infants had rather variable spectrums, unstable frequencies, and multiple harmonics in the first 20 days after birth. Infants over three weeks old mostly emitted FM-CF-FM type calls. Frequencies of first harmonics were significantly correlated with their age but the second harmonics did not correlate with age. The call frequencies of the young five-week-old bats were similar with their adults. The call frequency had a significant linear correlation with forearm length. Our findings indicated that the high flexible vocal cord and undeveloped nasal chamber might affect the vocalization veracity of new born infants.
Faeces were counted along horizontal, 5.0 m wide strips at altitude intervals of 100 m to examine the altitudinal ranging pattern of a band of black-and-white snub-nosed monkeys (Rhinopithecus bieti) at Nanren (99° 04'E, 28° 34'N, Baima Snow Mountain Nature Reverse, Yunnan, China) at four areas in each season between 2000-2001. Faeces were also counted along vertical, 2.5 m wide strips in one subvalley and on one subridge in each area. Monkeys used an altitudinal range of 3500-4300 m, but preferred occupying the upper forest belt between 3900 and 4200 m asl year-round, being at the highest altitude in summer, the lowest altitude in spring, and middle altitudes between autumn and winter (lower in winter than autumn). Moreover, there were secondary peaks of lower altitude use (3700 m) in spring and winter. In addition, more faeces were distributed in subvalleys than on subridges in winter, this suggests that monkeys tend to spend more time in subvalleys where there is less wind and fluctuating temperatures. The significant correlation between faecal density and lichen load might indicate that altitudinal distribution of food resources may act as an important factor affecting the monkeys' range. The monkeys might migrate to lower altitudes to eat young sprouts and leaves in spring, and to shelter from snowstorms in winter, possibly resulting in the secondary peaks at lower altitudes.
Huang et al describe a new species of cave-dwelling Triplophysa found during their exploration of cave animals in the Xiangxi Tujia and Miao Nationality Autonomous Prefecture, Hunan Province, central south China. The new species can be distinguished from other species of Triplophysa by the following combination of characters: eyes absent; body scaleless and colorless; caudal-fin 17; maxillary barbel longest; fins transparent, compressed pectoral-fin reaching 2/3 distance between pectoral-fin and pelvic-fin origins; pelvic-fin and dorsal-fin origins relative; posterior chamber of airbladder well developed, long, oval, and dissociative.
Why humans have large brains with higher cognitive abilities is a question long asked by scientists. However, much remains unknown, especially the underlying genetic mechanisms. With the use of a transgenic monkey model, we showed that human-specific sequence changes of a key brain development gene (Primary microcephaly1, MCPH1) could result in detectable molecular and cognitive changes resembling human neoteny, a notable characteristic developed during human evolution. MCPH1 is a key gene regulating brain development in humans, and its truncate mutations can cause primary microcephaly. Similarly, MCPH1 knockout in mice and monkeys can recapitulate the microcephaly phenotype, highlighting its critical role in mammalian brain development. This study represents the first attempt to utilize a transgenic monkey model to study human brain evolution. The results highlight the great potential of non-human primate models in studying human evolution and may pave the way for future studies to explore the genetic mechanisms of human-specific traits and elucidate the etiology of human brain disorders such as autism and Alzheimer's disease.
The Bama Xiang pig (BMX) is a famous early-maturing Chinese indigenous breed with a two-end black coat. To uncover the genetic basis of the BMX phenotype, we conducted comparative genomic analyses between BMX and East Asian wild boars and Laiwu pigs, respectively. Genes under positive selection were enriched in pathways associated with gonadal hormone and melanin synthesis, consistent with the phenotypic changes observed during development in BMX pigs. We also performed differentially expressed gene analysis based on RNA-seq data from pituitary tissues of BMX and Large White pigs. The CTTNBP2NL, FRS2, KANK4, and KATNAL1 genes were under selection and exhibited expressional changes in the pituitary tissue, which may affect BMX pig puberty. Our study demonstrated the positive selection of early maturity in the development of BMX pigs and advances our knowledge on the role of regulatory elements in puberty evolution in pigs.
The family Filoviridae, which includes the genera Marburgvirus and Ebolavirus, contains some of the most pathogenic viruses in humans and non-human primates (NHPs), causing severe hemorrhagic fevers with high fatality rates. Small animal models against filoviruses using mice, guinea pigs, hamsters, and ferrets have been developed with the goal of screening candidate vaccines and antivirals, before testing in the gold standard NHP models. In this review, we summarize the different animal models used to understand filovirus pathogenesis' and discuss the advantages and disadvantages of each model with respect to filovirus disease research.
The distribution of small mammals in mountainous environments across different elevations can provide important information on the effects of climate change on the dispersal of species. However, few studies conducted on Afromontane ecosystems have compared the altitudinal patterns of small mammal diversity. We investigated the species diversity and abundance of non-volant small mammals (hereafter 'small mammals') on Mt. Kenya, the second tallest mountain in Africa, using a standard sampling scheme. Nine sampling transects were established at intervals of 200 m on the eastern (Chogoria) and western (Sirimon) slopes. A total of 1 905 individuals representing 25 species of small mammals were trapped after 12 240 trap-nights. Abundance was highest at mid-elevations on both slopes. However, species richness and their distribution patterns differed between the two slopes. More species were recorded on Chogoria (24) than on Sirimon (17). On Chogoria, species richness was higher at mid-high elevations, with a peak at mid-elevation (2800 m a.s.l.), whereas species richness showed little variation on the Sirimon slope. These results indicate that patterns of species diversity can differ between slopes on the same mountain. In addition, we extensively reviewed literature on Mt. Kenya's mammals and compiled a comprehensive checklist of 76 mammalian species. However, additional research is required to improve our understanding of small mammal diversity in mountain habitats in Africa.
Protein arginine methyltransferases (PRMTs) are involved in many cellular processes via the arginine methylation of histone or non-histone proteins. We examined the expression patterns of prmt4, prmt7, and prmt9 during embryogenesis in Xenopus using whole-mount in situ hybridization and quantitative reverse transcription polymerase chain reaction (RT-PCR). Specific prmt9 signals were not detected in Xenopus embryos until the late tailbud stage when weak expression was observed in the branchial arches. Quantitative RT-PCR indicated that the expression of prmt4 and prmt7 was up-regulated during the neurula stage, whereas prmt9 maintained its low expression until the late tailbud stage, consistent with the whole-mount in situ hybridization results. Thus, the developmental expression patterns of these three prmt genes in Xenopus embryos provide a basis for further functional study of such genes.