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...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.展开更多
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 cha...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.展开更多
Scanning electron microscopy(SEM)and histological techniques were used to observe and study the structure of setae on the integument surface of the dung beetle Copris ochus Motschulsky and on the foot pad of the gecko...Scanning electron microscopy(SEM)and histological techniques were used to observe and study the structure of setae on the integument surface of the dung beetle Copris ochus Motschulsky and on the foot pad of the gecko Gekko gecko and their relationship to anti-adherent and adherent functions respectively.There are very distinctive comparison between the structures and the constructs of the setae on the dung beetle and the gecko:the setae of the dung beetle are ramification of the integument,mainly distributing on the body abdomen surface and the lateral side of the legs,loosely arranging,having different length with many buds and sticks along the whole seta body but without side branches,uprightly directing to the contacting dung face.The setae of the gecko are protuberances from the skin,arranging in order and densely,regularly directing,branching in twice with curved top.The histological observation found that dung beetle’s setae are empty inside with lots micro-foramens communicating to the inner side on the base of the buds and sticks on the seta and also connecting with the oil glands below the integument,but without the erect muscle. Gecko setae are surrounded by fat cells and muscles.Results from functional experiments suggest that deformation of the setae of the bung beetle integument could reduce the anti-adherent function and also the same kind of change could reduce the adherent function of the gecko setae on the leg bottom.These results offer important information for preparation of the soil machine and components imitating dung beetle setae flexible non-adherence and for designing artificial setae imitating the gecko’s adherent setae.展开更多
文摘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.
基金supported by the National Key R&D program of China (2019YFB1309600)National Natural Science Foundation of China (51975283).
文摘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.
文摘Scanning electron microscopy(SEM)and histological techniques were used to observe and study the structure of setae on the integument surface of the dung beetle Copris ochus Motschulsky and on the foot pad of the gecko Gekko gecko and their relationship to anti-adherent and adherent functions respectively.There are very distinctive comparison between the structures and the constructs of the setae on the dung beetle and the gecko:the setae of the dung beetle are ramification of the integument,mainly distributing on the body abdomen surface and the lateral side of the legs,loosely arranging,having different length with many buds and sticks along the whole seta body but without side branches,uprightly directing to the contacting dung face.The setae of the gecko are protuberances from the skin,arranging in order and densely,regularly directing,branching in twice with curved top.The histological observation found that dung beetle’s setae are empty inside with lots micro-foramens communicating to the inner side on the base of the buds and sticks on the seta and also connecting with the oil glands below the integument,but without the erect muscle. Gecko setae are surrounded by fat cells and muscles.Results from functional experiments suggest that deformation of the setae of the bung beetle integument could reduce the anti-adherent function and also the same kind of change could reduce the adherent function of the gecko setae on the leg bottom.These results offer important information for preparation of the soil machine and components imitating dung beetle setae flexible non-adherence and for designing artificial setae imitating the gecko’s adherent setae.
