Objective] The aim of this study was to investigate the electrophysiological characteristics of spontaneous electrical activities of olfactory bulb in Bufo gargarizans during postembryonic development. [Method] Microe...Objective] The aim of this study was to investigate the electrophysiological characteristics of spontaneous electrical activities of olfactory bulb in Bufo gargarizans during postembryonic development. [Method] Microelectrode technique was used to record extracellular spontaneous electrical activities of olfactory bulb in B. gar-garizans. [Result] Along with the development of olfactory bulb, the discharge types increased gradual y. Single spontaneous firing enhanced gradual y and it reached the maximum in the metamorphosis phase. The intensity of consecutive single sponta-neous firing changed slightly at the middle of post-embryonic development, but it was stil higher than in the early phase and the adult phase. Consecutive burst spontaneous firing frequency went down over time. [Conclusion] Along with the de-velopment of olfactory bulb, the neuronal excitability increases step by step and the neuronal electrical activities diversify gradualy.展开更多
[ Objective ] The purpose was to provide a reference for crossbreeding of grass carp. [ Method] We conducted hybridization between Ctenopharyngodon ideUus （ ♀ ） and Elopichthys bambusa ♂ ） by artificial methods. ...[ Objective ] The purpose was to provide a reference for crossbreeding of grass carp. [ Method] We conducted hybridization between Ctenopharyngodon ideUus （ ♀ ） and Elopichthys bambusa ♂ ） by artificial methods. The process of embryo and postembryonic development were observed and recorded. [ Result ] The fertilization rate, hatching rate and survival rate of the hybrid F1 were （75.8 ± 6. 2）%, （41.9 ± 8.2）% and （9.3± 3.7）%, respectively. At the water temperature of 20.1 -21.6℃, the larvae was hatched for about 34 h and 25 rain after fertilization. The whole length of newly-hatched larvae of the hybrid Fl was （5.8 ± 0.12） mm. The larvae could feed rotifer and unicellular algae after 3 or 4 days hatching. Postembryonic development of the hybrid at the formation of scales, lasted for 65 days when the young was（74.0 ± 2.1 ） mm in whole length. [ Conclusion] The embryonic development of hybrid F1 was intermediate to their parents, the form of the hybrid F1 was similar to that of their female line of grass carp. The growth rate of larva was faster than that of grass carp and similar to that of their paternal fish.展开更多
This study aimed to investigate the morphological characteristics of Percocypris pingi pingi （Tchang） at the embryonic and postembryonic developmental periods and to demonstrate the early developmental stage of P. p...This study aimed to investigate the morphological characteristics of Percocypris pingi pingi （Tchang） at the embryonic and postembryonic developmental periods and to demonstrate the early developmental stage of P. pingi pingi （Tchang）. According to the results, the fully mature eggs were spherical, orange-col- ored, sticky, 2.2 mm in diameter; the maximum outer diameter reached 3.2 -3.8 mm after absorbing water. When water temperature was （18 -＋ 0.5） ~C, the first cleavage occun~ at 2h 28 min post-fertilization; organs began to form at 45 h 23 min post-fertilization; larvae were hatched at 126 h 28 min post-fertilization. Newly hatched larvae exhibited a total length of 10.4 mm, with large and compressed yolk sacs. According to the morphological characteristics, the embryonic de- velopmental process of P. pingi pingi （Tchang） could be divided into seven continuous stages, including fertilized egg stage, cleavage stage, blastula stage, early gastrula stage, neurala stage, organ formation stage and hatching stage, which were further divided into 32 phases. When water temperature ranged from 18.8 ~C to 25.0 ~C, the whole developmental process of P. pingi pingi （Tchang） from larvae to juveniles lasted 93 d. According to the morphological and ecological charac- teristics, the pestembryonic developmental process of P. pingi pingi （Tchang） could be divided into three stages, including yolk-sac larva stage, late larva stage and junenile stage. This study laid solid foundation for .展开更多
The thyroid hormones L-thyroxine and triiodo-L-thyronine have profound effects on postembryonic development of most vertebrates. Analysis of their action in mammals is vitiated by the exposure of the developing foetus...The thyroid hormones L-thyroxine and triiodo-L-thyronine have profound effects on postembryonic development of most vertebrates. Analysis of their action in mammals is vitiated by the exposure of the developing foetus to a number of maternal factors which do not allow one to specifically define the role of thyroid hormone (TH)or that of other hormones and factors that modulate its action. Amphibian metamorphosis is obligatorily dependent on TH which can initiate all the diverse physiological manifestations of this postembryonic developmental process(morphogenesis, cell death, re-structuring, etc.) in free-living embryos and larvae of most anurans. This article will first describe the salient features of metamorphosis and its control by TH and other hormones. Emphasis will be laid on the key role played by TH receptor (TR), in particular the phenomenon of TR gene autoinduction, in initiating the developmental action of TH. Finally, it will be argued that the findings on the control of amphibian metamorphosis enhance our understanding of the regulation of postembryonic development by TH in other vertebrate species.展开更多
Goldfish(Carassius auratus auratus)are important ornamental fish that have experienced extreme anthropogenic selection and exhibit diverse phenotypes.Loss of the dorsal fin is a key characteristic that distinguishes t...Goldfish(Carassius auratus auratus)are important ornamental fish that have experienced extreme anthropogenic selection and exhibit diverse phenotypes.Loss of the dorsal fin is a key characteristic that distinguishes the Egg-goldfish from the Wen-goldfish.However,the mechanisms underlying the divergence in dorsal fin development are still unknown between the Egg-goldfish and the Wen-goldfish.In this study,we sought to unravel the postembryonic developmental processes of two goldfish strains,Red Cap Oranda,a representative of the Wen-goldfish,and Ranchu,a representative of the Egg-goldfish.We examined the developmental morphology of the dorsal fin in five-month-old goldfish larvae using both Alcian blue-alizarin red staining and X-ray photography.We showed that the developmental processes of the dorsal fin fold were different in Ranchu compared to Red Cap Oranda,despite similarity in their general developmental processes.We categorized the postembryonic development of Ranchu larvae into four types based on the number of the initial residual dorsal fin fold appearing at protruding-mouth stage.The number,size and position of the initial residual dorsal fin fold appeared at hatching affected and eventually determined the phenotypic variations in dorsal fin defects in Ranchu.In addition,we genotyped the eomesa gene to determine whether it would be a candidate gene responsible for the loss of the dorsal fin in Ranchu.The eomesa CDS sequence exhibited no nonsense mutation in Ranchu.In summary,the absence of the dorsal fin fold during postembryonic development eventually resulted in the loss of the dorsal fin in Ranchu.Further investigation is required to determine whether other genes and developmental pathways play important roles in the loss of the dorsal fin in Ranchu.展开更多
基金Supported by grants from the Liaoning Provincial Department of Education(2011196)the Experimental Center Director Fund of Shenyang Normal University(sy201003)~~
文摘Objective] The aim of this study was to investigate the electrophysiological characteristics of spontaneous electrical activities of olfactory bulb in Bufo gargarizans during postembryonic development. [Method] Microelectrode technique was used to record extracellular spontaneous electrical activities of olfactory bulb in B. gar-garizans. [Result] Along with the development of olfactory bulb, the discharge types increased gradual y. Single spontaneous firing enhanced gradual y and it reached the maximum in the metamorphosis phase. The intensity of consecutive single sponta-neous firing changed slightly at the middle of post-embryonic development, but it was stil higher than in the early phase and the adult phase. Consecutive burst spontaneous firing frequency went down over time. [Conclusion] Along with the de-velopment of olfactory bulb, the neuronal excitability increases step by step and the neuronal electrical activities diversify gradualy.
基金Supported by Wuhan Science and Technology Plan Projects(2013021001010464)
文摘[ Objective ] The purpose was to provide a reference for crossbreeding of grass carp. [ Method] We conducted hybridization between Ctenopharyngodon ideUus （ ♀ ） and Elopichthys bambusa ♂ ） by artificial methods. The process of embryo and postembryonic development were observed and recorded. [ Result ] The fertilization rate, hatching rate and survival rate of the hybrid F1 were （75.8 ± 6. 2）%, （41.9 ± 8.2）% and （9.3± 3.7）%, respectively. At the water temperature of 20.1 -21.6℃, the larvae was hatched for about 34 h and 25 rain after fertilization. The whole length of newly-hatched larvae of the hybrid Fl was （5.8 ± 0.12） mm. The larvae could feed rotifer and unicellular algae after 3 or 4 days hatching. Postembryonic development of the hybrid at the formation of scales, lasted for 65 days when the young was（74.0 ± 2.1 ） mm in whole length. [ Conclusion] The embryonic development of hybrid F1 was intermediate to their parents, the form of the hybrid F1 was similar to that of their female line of grass carp. The growth rate of larva was faster than that of grass carp and similar to that of their paternal fish.
基金Supported by Special Fund for Scientific Research in the Public Interest from the Ministry of Agriculture"Protection and Utilization of Fish Resources in the Middle Reach of Brahmaputra River"(201403012)Youth Fund for Breeding Project from Sichuan Department of Finance(2009QNJJ-022)
文摘This study aimed to investigate the morphological characteristics of Percocypris pingi pingi （Tchang） at the embryonic and postembryonic developmental periods and to demonstrate the early developmental stage of P. pingi pingi （Tchang）. According to the results, the fully mature eggs were spherical, orange-col- ored, sticky, 2.2 mm in diameter; the maximum outer diameter reached 3.2 -3.8 mm after absorbing water. When water temperature was （18 -＋ 0.5） ~C, the first cleavage occun~ at 2h 28 min post-fertilization; organs began to form at 45 h 23 min post-fertilization; larvae were hatched at 126 h 28 min post-fertilization. Newly hatched larvae exhibited a total length of 10.4 mm, with large and compressed yolk sacs. According to the morphological characteristics, the embryonic de- velopmental process of P. pingi pingi （Tchang） could be divided into seven continuous stages, including fertilized egg stage, cleavage stage, blastula stage, early gastrula stage, neurala stage, organ formation stage and hatching stage, which were further divided into 32 phases. When water temperature ranged from 18.8 ~C to 25.0 ~C, the whole developmental process of P. pingi pingi （Tchang） from larvae to juveniles lasted 93 d. According to the morphological and ecological charac- teristics, the pestembryonic developmental process of P. pingi pingi （Tchang） could be divided into three stages, including yolk-sac larva stage, late larva stage and junenile stage. This study laid solid foundation for .
文摘The thyroid hormones L-thyroxine and triiodo-L-thyronine have profound effects on postembryonic development of most vertebrates. Analysis of their action in mammals is vitiated by the exposure of the developing foetus to a number of maternal factors which do not allow one to specifically define the role of thyroid hormone (TH)or that of other hormones and factors that modulate its action. Amphibian metamorphosis is obligatorily dependent on TH which can initiate all the diverse physiological manifestations of this postembryonic developmental process(morphogenesis, cell death, re-structuring, etc.) in free-living embryos and larvae of most anurans. This article will first describe the salient features of metamorphosis and its control by TH and other hormones. Emphasis will be laid on the key role played by TH receptor (TR), in particular the phenomenon of TR gene autoinduction, in initiating the developmental action of TH. Finally, it will be argued that the findings on the control of amphibian metamorphosis enhance our understanding of the regulation of postembryonic development by TH in other vertebrate species.
基金This work was financially supported by the SHOU&MSU Joint Research Center grant.
文摘Goldfish(Carassius auratus auratus)are important ornamental fish that have experienced extreme anthropogenic selection and exhibit diverse phenotypes.Loss of the dorsal fin is a key characteristic that distinguishes the Egg-goldfish from the Wen-goldfish.However,the mechanisms underlying the divergence in dorsal fin development are still unknown between the Egg-goldfish and the Wen-goldfish.In this study,we sought to unravel the postembryonic developmental processes of two goldfish strains,Red Cap Oranda,a representative of the Wen-goldfish,and Ranchu,a representative of the Egg-goldfish.We examined the developmental morphology of the dorsal fin in five-month-old goldfish larvae using both Alcian blue-alizarin red staining and X-ray photography.We showed that the developmental processes of the dorsal fin fold were different in Ranchu compared to Red Cap Oranda,despite similarity in their general developmental processes.We categorized the postembryonic development of Ranchu larvae into four types based on the number of the initial residual dorsal fin fold appearing at protruding-mouth stage.The number,size and position of the initial residual dorsal fin fold appeared at hatching affected and eventually determined the phenotypic variations in dorsal fin defects in Ranchu.In addition,we genotyped the eomesa gene to determine whether it would be a candidate gene responsible for the loss of the dorsal fin in Ranchu.The eomesa CDS sequence exhibited no nonsense mutation in Ranchu.In summary,the absence of the dorsal fin fold during postembryonic development eventually resulted in the loss of the dorsal fin in Ranchu.Further investigation is required to determine whether other genes and developmental pathways play important roles in the loss of the dorsal fin in Ranchu.
