Heat shock factor 1 promotes neurite outgrowth and suppresses inflammation in the severed spinal cord of geckos

The low intrinsic growth capacity of neurons and an injury-induced inhibitory milieu are major contributo rs to the failure of sensory and motor functional recovery following spinal cord injury.Heat shock transcription factor 1(HSF1),a master regulator of the heat shock response,plays neurogenetic and neuroprotective roles in the damaged or diseased central nervous system.However,the underlying mechanism has not been fully elucidated.In the present study,we used a gecko model of spontaneous nerve regeneration to investigate the potential roles of gecko HSF1(gHSF1) in the regulation of neurite outgrowth and inflammatory inhibition of macrophages following spinal cord injury.gHSF1 expression in neurons and microglia at the lesion site increased dramatically immediately after tail amputation.gHSF1 ove rexpression in gecko primary neuro ns significantly promoted axonal growth by suppressing the expression of suppressor of cytokine signaling-3,and fa cilitated neuro nal survival via activation of the mitogen-activated extracellular signal-regulated kinase/extracellular regulated protein kinases and phosphatidylinositol 3-kinase/protein kinase B pathways.Furthermore,gHSF1 efficiently inhibited the macrophagemediated inflammatory response by inactivating 1kappa B-alpha/NF-kappaB signaling.Our findings show that HSF1 plays dual roles in promoting axonal regrowth and inhibiting leukocyte inflammation,and provide new avenues of investigation for promoting spinal co rd injury repair in mammals.

Diversifying on the Ark:multiple new endemic lineages of dwarf geckos from the Western Ghats provide insights into the systematics and biogeography of South Asian Cnemaspis(Reptilia:Squamata)

The highly speciose gekkonid genus Cnemaspis Strauch,1887 is polyphyletic,with three distantly related and geographically isolated clades from Africa,South Asia(SA),and Southeast Asia.At present,there are 85 known species within SA Cnemaspis,although the number continues to increase rapidly with focused surveys and rigorous taxonomic work.Recent studies have provided valuable insights into the diversity and evolutionary history of SA Cnemaspis;however,most of these studies lack sufficient sampling in the Western Ghats(WG),where the genus has its greatest diversity.We addressed this research gap by conducting extensive sampling across the WG and re-examining museum specimens,thus providing a systematic account of various extant Cnemaspis species along with their distribution and natural history.We described 12 new species and a southern WG endemic clade of SA Cnemaspis.Ten of the newly described species are endemic to the forests of the southern WG.We also identified 10 well-supported subclades that can be separated across morphological,geographic,and phylogenetic axes.A time-calibrated phylogeny and ancestral area reconstructions confirmed the Paleocene origin of SA Cnemaspis in the WG and provide insights into its evolutionary history and biogeography.The discovery of multiple endemic and deeply divergent lineages further highlights the evolutionary significance of the WG for lizards.

Molecular Evolution of Visual Opsin Genes during the Behavioral Shifts between Different Photic Environments in Geckos

Reptiles are the most morphologically and physiologically diverse tetrapods,with the squamates having the most diverse habitats.Lizard is an important model system for understanding the role of visual ecology,phylogeny and behavior on the structure of visual systems.In this study,we compared three opsin genes(RH2,LWS and SWS1)among 49 reptile species to detect positively selected genes as well as amino acid sites.Our results indicated that visual opsin genes have undergone divergent selection pressures in all lizards and RH2 and LWS suffered stronger positive selection than SWS1.Twelve positively selected sites were picked out for RH2 and LWS.Moreover,many diagnostic sites were found between geckos and non-gecko lizards,most of which were located near the positively selected sites and some of them have already been reported to be responsible for significant shifts of the wavelength of maximum absorption(λ_(max)).The results indicated that the gecko lineage accelerated the evolution of these genes to adapt to the dim-light environment or nocturnality as well as the switch between nocturnality and diurnality.

Behaviours in Attachment-Detachment Cycles of Geckos in Response to Inclines and Locomotion Orientations

Geckos can move quickly in various environments by efficiently controlling their complex adhesive toe pads.The locomotion behaviours observed in the attachment-detachment(A-D)cycle of their toe pads in response to changes in their environment should be studied to understand the adaptive behavioural characteristics of such toe pads.The lack of systematic research on the entire A-D cycle,including the release,swing,contact,and adhesion stages,limits the comprehension of the adhesive locomotion mechanism.The A-D cycle of Gekko gecko that facilitates the foot locomotion on inclined and vertical surfaces was investigated to clarify the locomotion behaviours in different stages.Results show that the change trends of foot locomotor angles(yaw and pitch)during the entire A-D cycle remain unchanged in response to various substrates.The bending angles(fore 41°;hind 51°)and contact time percentages(fore 7.42%;hind 7.44%)in the contact stage as well as the forefoot angle ranges(yaw:163.09°;pitch:308.68°)in the A-D cycle also remain constant across all substrates.These invariant foot locomotion behaviours during the swing and contact stages suggest that the foot behaviours are weakly related to the forces acting on the foot,which change according to the environment.Furthermore,the forefoot and hindfoot have different anatomical structure and functional demands,thus,the angle range of forefoot locomotion is larger than that of hindfoot locomotion,and the pitch angle change trend of the forefoot is opposite to that of the hindfoot.The diverse and complex locomotion control of the adhesive toe pads for various environments is reduced by the consistent behaviours in the gecko’s A-D cycle,such as the constant postures in the swing and contact stages.This study provides insight into the adhesive locomotion mechanism of geckos and can facilitate further research on the effective design and control of adhesion robots.

Effect of Slope Degree on the Lateral Bending in Gekko geckos

A gecko＇s habitat possesses a wide range of climbing slopes that pose a number of postural challenges for climbing lo- comotion. Few studies have examined the relationship between the lateral bending of the trunk of a gecko and other aspects of locomotion when climbing. In this paper, three-dimensional reaction forces and high-speed videos of Gekko geckos moving on different slopes are used to reveal how the lateral bending of the animal＇s trunk responds to changing slopes. The results of such observations indicate that the minimum bending radius continually decreases with an increase in the slope, illustrating that the degree of bending of the trunk becomes significantly greater. Moreover, a lateral bending mechanical model is used to show the interrelation between the lateral bending in the frontal plane and the sagittal deformation of the trunk caused by gravity. Taken together, these results have advanced our understanding of the role of lateral bending of vertebrates when climbing on a slope.

Electrostatic attraction caused by triboelectrification in climbing geckos

Adhesion achieved through feet setae is fundamental for gecko agilely maneuvering.Although diverse hypotheses have been proposed,none of them thoroughly explains the setae function,implying a kind of hybrid-mechanism-based adhesion in geckos.In addition to van der Waals interactions and capillary force,the electrostatic attraction that emerges from triboelectrification was suggested as a component of setae adhesion.Nevertheless,the contribution by electrostatic attraction to the total setae attachment is still controversial.In this study,we analyzed the occurrence of electrostatic attraction at gecko setae through experiments and model analyses.By touching the substrates with only~1/70th of the foot area,freely wall-climbing geckos developed tribocharge at their feet setae with a density of~277 pC/mm^(2),generating electrostatic attractions with a strength of~4.4 mN/mm^(2).From this perspective,the adhesion driven by triboelectrification could account for about 1%of total adhesion.Model analyses at spatula level indicated a similar result showing that the electrostatic force might account for~3%of the adhesion that facilitates wall-climbing in geckos.The low contribution of the electrostatic force partly explains why geckos always face difficulty in maneuvering onto those substrates(e.g.,teflon)where they could easily develop tribocharge but difficultly generate van der Waals force.However,long-range electrostatic forces may play other roles in a distance range where the van der Waals interaction cannot function.These findings not only add to our understanding of the mechanism of gecko adhesion,but also will help us advance gecko-inspired fibular adhesives.

Analysis of Reaction Force and Locomotor Behavior on Geckos in Time-and Frequency-domain during Climbing on Vertical Substrates

Since the commencement of climbing robots,the moving ability of climbing robots has continuously lagged far behind that of climbing animal.A primary cause is the insufficient understanding of how animals govern their climbing locomotion.To reveal the mechanism of vertical locomotion and enhance the performance of climbing robots,we have measured the reaction forces acting on climbing geckos and recorded the locomotor behaviors synchronously.The coordinates of reference points were regressed to analyze kinematic feature factors.Meanwhile,the data of reaction forces were further processed by fast Fourier transform and wavelet transform to acquire time-frequency domain characteristics.The results show a good agreement between the reaction forces and the locomotor behaviors in time-frequency domain;the main locomotor frequency of trunk in fore-aft direction is twice that in lateral direction;the excellent adhesion system of geckos enables them to climbing up vertical substrate with not onIy a very tiny impact in time scale but also not easily identifiable characteristics in frequency-domain.Above research will help deepen our understanding of the climbing locomotion,and provide a more precise prototype for the design of gecko-like robot.

电刺激大壁虎(Gekko gecko)中脑诱导转向运动的研究

为探索大壁虎运动行为脑功能基础和人工诱导的可能性,用不锈钢微电极对头部固定状态下浅麻醉的大壁虎(Gekko gecko,n=20)中脑脑区施以生理范围内的电刺激.发现中脑被盖区域在电刺激下可诱导出大壁虎脊柱侧弯和四肢动(外伸、内收、抬腿迈步等动作)等一系列多肌群参与的复杂运动行为;根据急性实验结果,通过在中脑被盖特定脑区植入金属微电极对术后恢复一周的清醒状态下的大壁虎(n=20)脑区施加电刺激信号,可成功地诱导出左、右转向的运动行为.该结果发现大壁虎中脑与运动行为密切相关,而且通过刺激脑内相关的核团可能实现对大壁虎部分运动行为的人工诱导.这为大壁虎运动的人工制导提供了有益的信息.

Complete Sequence and Gene Organization of the Mitochondrial Genome of Tokay (Gekko gecko)

Long-PCR amplification, clone and primer-walking sequencing methods were employed in determine the complete sequence of mitochondrial genome of tokay (Gekko gecko). The genome is 16 435 bp in size, contains 13 protein-coding, 2 ribosomal and 22 transfer RNA genes. The mt genome of Gekko is similar to most of the vertebrates in gene components, order, orientation, tRNA structures, low percentage of guanine and high percentage of thymine, and skews of base GC and AT. Base A was preferred at third codon positions for protein genes is similar to amphibians and fishes rather than amnion vertebrates. The standard stop codes (TAA) present only in three protein genes, less than those of most vertebrates. Transfer RNA genes range in length from 63 to 76 nt, their planar structure present characteristic clover leaf, except for tRNA-Cys and tRNA-Ser (AGY) because of lacking the D arm.

Description of two new species of Hemiphyllodactylus(Reptilia: Gekkonidae) from karst landscapes in Yunnan, China, highlights complex conservation needs

Karst habitats are hotspots of diversity and endemism. Their naturally fragmented distributions across broad geographic landscapes have led to the complex array of smaller evolutionary ecosystems that present unique challenges from a conservation perspective.Comprehensivebiodiversity assessments of karst habitats have revealed that these ecosystems contain an almost unparalleled level of endemism, and many site-restricted species remain undescribed, thus posing considerable challenges for effective conservation management.Small rock-dwelling species, such as geckos, may be particularly prone to such isolation. In this paper, we discuss one such genus, i.e.,Hemiphyllodactylus, and explore its diversity across karst landforms in Yunnan Province, southwestern China. Based on morphological and genetic data, we describe two new species of Hemiphyllodactylus from karst habitats in Simao District and Yanshan County. A phylogenetic tree for Hemiphyllodactylus was constructed using 1?039 base pairs(bp) of the mitochondrial NADH dehydrogenase subunit 2 gene(ND2). The Simao and Yanshan specimens can be distinguished from all other congeners within their respective subclades based on uncorrected genetic pairwise distances greater than 6.3% and 4.3%respectively, as well as significant morphological differences. The discovery and description of these two new species brings the total number of described Hemiphyllodactylus species in China to 14and indicates many more undescribed species from unsurveyed karst regions await discovery.Our findings suggest that karst ecosystems in Yunnan support a higher diversity of Hemiphyllodactylus than previously known.This study also highlights the importance of karst ecosystems as refugia for sitespecific endemic species and the need for heightened conservation efforts.

Biochemical variability between two Egyptian <i>Stenodactylus </i>species (Reptilia: Gekkonidae) inhabiting North Sinai

Polyacrylamide gel electrophoreses for malate dehydrogenase (Mdh) and beta-esterase (β-Est) isoenzymes were conducted for biochemical differentiation between two Stenodactylus gekkonid species inhabiting North Sinai of Egypt. Total lipids and proteins of liver and muscle tissues in both species were also analyzed. A total of three Mdh isoforms were recorded in the analysis, in which the activity of Mdh-2 and Mdh-3 seemed to be higher in S. petrii than in S. sthenodactylus. This high activity could be supported by the significant increase in the total lipids and proteins in liver and muscle tissues of the species. It may thus be reasonable to suppose that S. petrii is more active, energetic and adaptable in the desert habitat than S. sthenodactylus. β-Est showed six fractions in S. petrii and only one fraction in S. sthenodactylus. It is therefore noticeable that β-Est is more highly expressed in S. petrii than in S. sthenodactylus.

“风药”大壁虎(Gekko gecko,蛤蚧)角膜上皮超微结构的研究

大壁虎的4种组织已经报道过,本文对它的角膜加以研究。角膜组织剪取后,经4%戊二醛和1%锇酸双重固定,扫描电镜常规技术处理后,用S-520扫描电子显微镜进行观察拍照。它的最表层细胞当冲去泪液膜后,为扁平细胞,细胞间有桥粒连接。电镜下放大10000倍以上时。

“风药”大壁虎(Gekko gecko,蛤蚧)消化系统的超微结构

文[1～3]已对大壁虎的四大组织超微结构加以介绍。按照解剖学的体系,本文着重报道它消化系统的超微结构。取大壁虎消化系统的舌、胃、肠、肝和胆囊5个部分的材料,用扫描电子显微镜进行观察。

“风药”大壁虎(Gekko gecko,蛤蚧)组织的超微结构研究

前文对大壁虎的上皮组织的皮肤鳞片和指、趾的超微结构已有报告。本文按动物的组织学顺序对它的结缔组织、骨组织、血细胞、肌组织和神经组织的观察结果,报道如下。

“风药”大壁虎(Gekko gecko蛤蚧)指、趾的超微结构研究

前已对大壁虎的鳞片组织亚显微结构作了报道,本文就应用电镜技术对大壁虎四肢中较具特色的指和趾观察结果,报道如下。本文所用动物来源及方法与前文同。

.NET互操作下Gecko浏览器组件

在讨论.NET互操作技术的平台调用,COM组件互操作,数据封送与Gecko内核浏览器的运行环境XULRunner及跨平台对象模型XPCOM的基础上,根据其操作思路,通过互操作把.NET与Gecko内核两者相结合,创建了.NET环境下通过XPCOM组件控制的Gecko内核浏览器控件,使其同时具备异构复用、可扩展、可操作的特点.

A Biomimetic Climbing Robot Based on the Gecko

The excellent climbing performance of the gecko is inspiring engineers and researchers for the design of artificial systems aimed at moving on vertical surfaces. Climbing robots could perform many useful tasks such as surveillance, inspection, repair, cleaning, and exploration. This paper presents and discusses the design, fabrication, and evaluation of two climbing robots which mimic the gait of the gecko. The first robot is designed considering macro-scale operations on Earth and in space. The second robot, whose motion is controlled using shape memory alloy actuators, is designed to be easily scaled down for micro-scale applications. Proposed bionic systems can climb up 65 degree slopes at a speed of 20 mm·s^-1.

Antitumor effect and mechanism of Gecko on human esophageal carcinoma cell lines in vitro and xenografted sarcoma 180 in Kunming mice

AIM: To investigate the anti-tumor effect of Chinese medicine Gecko on human esophageal carcinoma cell lines and xenografted sarcoma 180 in Kunming mice and its mechanism. METHODS: The serum pharmacological method was used in vitro . The growth rates of the human esophageal carcinoma cells (EC9706 or EC1) were measured by a modifi ed 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The transplanted tumor model of the mouse S180 sarcoma was established. Fifty mice were randomly divided into fi ve groups (n = 10). Three Gecko groups were treated respectively with oral administration of Gecko powder at a daily dose of 13.5 g/kg, 9 g/kg, and 4.5 g/kg. The negative group (NS group) was treated with oral administration of an equal volume of saline and the positive group (CTX group) was treated with 100 mg/kg Cytoxan by intraperitoneal injection at the fi rst day. After 2 wk of treatment, the anti-tumor activity was evaluated by tumor tissue weighing. The impact on immune organ was detected based on the thymus index, spleen index, phagocytic rate and phagocytic index. The protein expression of vascular endothelingrowth factor (VEGF) and basic fibroblast growth factor (bFGF) were detected by immunohistochemistry. The cell apoptotic rate was detected by terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) assay. RESULTS: The A value in each group treated with Gecko after 72 h was reduced signif icantly in EC9706 and in EC1. The tumor weight in each group of Gecko was decreased signifi cantly (1.087 ± 0.249 vs 2.167 ± 0.592; 1.021 ± 0.288 vs 2.167 ± 0.592; 1.234 ± 0.331 vs 2.167 ± 0.592; P < 0.01, respectively). However, the thymus index and Spleen index of mice in Gecko groups had no significant difference compared with the NS group. The immunoreactive score of VEGF and bFGF protein expression of each Gecko group by immunohistochemical staining were lowered signifi cantly. The apoptosis index (AI) of each group was increased progressively with increase of dose of Gecko by TUNEL. CONCLUSION: Gecko has anti-tumor effects in vitro and in vivo; induction of tumor cell apoptosis and the down-regulation of protein expression of VEGF and bFGF may be contributed to anti-tumor effects of Gecko.

Multi-Scale Compliant Foot Designs and Fabrication for Use with a Spider-Inspired Climbing Robot

Climbing robots are of potential use for surveillance, inspection and exploration in different environments. In particular, the use of climbing robots for space exploration can allow scientists to explore environments too challenging for traditional wheeled designs. To adhere to surfaces, biomimetic dry adhesives based on gecko feet have been proposed. These biomimetic dry adhesives work by using multi-scale compliant mechanisms to make intimate contact with different surfaces and adhere by using Van der Waals forces. Fabrication of these adhesives has frequently been challenging however, due to the difficulty in combining macro, micro and nanoscale compliance. We present an all polymer foot design for use with a hexapod climbing robot and a fabrication method to improve reliability and yield. A high strength, low-modulus silicone, TC-5005, is used to form the foot base and microscale fibres in one piece by using a two part mold. A macroscale foot design is produced using a 3D printer to produce a base mold, while lithographic definition of microscale fibres in a thick photoresist forms the ＇hairs＇ of the polymer foot. The adhesion of the silicone fibres by themselves or attached to the macro foot is examined to determine best strategies for placement and removal of feet to maximize adhesion. Results demonstrate the successful integration of micro and macro compliant feet for use in climbing on a variety of surfaces.

Kinematic Analysis and Experimental Verification on the Locomotion of Gecko

This paper presents a kinematic analysis of the locomotion of a gecko,and experimental verification of the kinematic model.Kinematic analysis is important for parameter design,dynamic analysis,and optimization in biomimetic robot research. The proposed kinematic analysis can simulate,without iteration,the locomotion of gecko satisfying the constraint conditions that maintain the position of the contacted feet on the surface.So the method has an advantage for analyzing the climbing motion of the quadruped mechanism in a real time application.The kinematic model of a gecko consists of four legs based on 7-degrees of freedom spherical-revolute-spherical joints and two revolute joints in the waist.The motion of the kinematic model is simulated based on measurement data of each joint.The motion of the kinematic model simulates the investigated real gecko's motion by using the experimental results.The analysis solves the forward kinematics by considering the model as a combination of closed and open serial mechanisms under the condition that maintains the contact positions of the attached feet on the ground. The motions of each joint are validated by comparing with the experimental results.In addition to the measured gait,three other gaits are simulated based on the kinematic model.The maximum strides of each gait are calculated by workspace analysis.The result can be used in biomimetic robot design and motion planning.