During spawning events, horseshoe crab eggs are released from the female＇s oviducts, and fertilized by one or more males. Eggs are shaped by the female into discrete clutches deposited in nests at depths of 10-20 cm ...During spawning events, horseshoe crab eggs are released from the female＇s oviducts, and fertilized by one or more males. Eggs are shaped by the female into discrete clutches deposited in nests at depths of 10-20 cm on intertidal estuarine beaches. Distinguishing between fxesh eggs and the early developmental stages is obfuscated by the large amount of dense, opaque yolk. The first unambiguous confirmation of development is the formation of the rudimentary prosomatie appendages at the ＂limb bud＂ stage. Several days thereafter, the outer chorion is shed and the developing embryo expands and undergoes a series of molts within the clear inner egg membrane. The trilobite （first iustar） stage thus attained may remain within the beach sedi- ments for several more weeks, until hatching is facilitated by environmental factors such as hydration, agitation, and osmotic shock that accompany the infiltration of seawater into the nests. Trilobites exhibit endogenous eirgatidal swimming rhythms that are entrained by mechanical agitation, suggesting that peaks in larval swimming are timed to coincide with periods of high water and the inundation of the nests. Larval swimming is limited and does not appear to result in long-distance dispersal. The limited dispersal of the larvae has important implications for the population dynamics of relatively isolated populations. The rate of larval development is highly plastic and is influenced by temperature, salinity, dissolved oxygen, and the presence of pollutants. The broad environmental tolerances of horseshoe crab embryos and larvae are important in understanding their current geographic distribution and their evolutionary persistence展开更多
MyoD, Myf5, and myogenin are myogenic regulatory factors that play important roles during myogenesis. It is thought that MyoD and Myf5 are required for myogenic determination, while myogenin is important for terminal ...MyoD, Myf5, and myogenin are myogenic regulatory factors that play important roles during myogenesis. It is thought that MyoD and Myf5 are required for myogenic determination, while myogenin is important for terminal differentiation and lineage maintenance. To better understand the function of myogenic regulatory factors in muscle development of flounder, an important economic fish in Asia, real-time quantitative RT-PCR was used to characterize the expression patterns of MyoD, Myf5, and myogenin at early stages of embryo development, and in different tissues of the adult flounder. The results show that, MyJ5 is the first gene to be expressed during the early stages of flounder development, followed by MyoD and myogenin. The expressions ofMyf5, MyoD, and myogenin at the early stages have a common characteristic： expression gradually increased to a peak level, and then gradually decreased to an extremely low level. In the adult flounder, the expression of the three genes in muscle is much higher than that in other tissues, indicating that they are important for muscle growth and maintenance of grown fish. During embryonic stages, the expression level of MyoD might serve an important role in the balance between muscle cell differentiation and proliferation. When the MyoD expression is over 30% of its highest level, the muscle cells enter the differentiation stage.展开更多
To investigate the effects of elevated seawater p CO_2 on the early developmental stages of marine benthic calcifying organisms, we exposed the eggs and larvae of Argopecten irradias, an important bivalve species in C...To investigate the effects of elevated seawater p CO_2 on the early developmental stages of marine benthic calcifying organisms, we exposed the eggs and larvae of Argopecten irradias, an important bivalve species in Chinese aquaculture, in seawater equilibrated with CO_2-enriched(1000 ppm) gas mixtures. We demonstrated that elevated seawater pCO_2 significantly interfered with fertilization and larval development and resulted in an increased aberration rate. Fertilization in the treatment(pH 7.6) was 74.3% ± 3.8%, which was 9.7% lower than that in the control(p H 8.3)(84.0% ±3.0%). Hatching success decreased by 23.7%, and aberration rate increased by 30.3% under acidic condition. Larvae in acidified seawater still developed a shell during the post-embryonic phase. However, the shell length and height in the treatment were smaller than those in the control. The development of embryos differed significantly at 12 h after fertilization between the two experimental groups. Embryos developed slower in acidified seawater. Nearly half of the embryos in the control developed into D-shaped larvae at 48 h after fertilization, which were considerably more than those in the treatment(11.7%). Results suggest that future ocean acidification(OA) would cause detrimental effects on the early development of A. irradias.展开更多
Mammalian cortical development is a dynamically and strictly regulated process orchestrated by extracellular signals and intracellular mechanisms. Recent studies show that epigenetic regulation serves as, at least in ...Mammalian cortical development is a dynamically and strictly regulated process orchestrated by extracellular signals and intracellular mechanisms. Recent studies show that epigenetic regulation serves as, at least in part, interfaces between genes and the environment, and also provides insight into the molecular and cellular bases of early embryonic cortical development. It is becoming increasingly clear that epigenetic regulation of cortical development occurs at multiple levels and that comprehensive knowledge of this complex regulatory landscape is essential to delineating embryonic neurogenesis.展开更多
基金supported by a series of awards from New Jersey Sea Grantsupport from the U.S. Army Corps of Engineers, Philadelphia Districtsupported by National Park Service Grants Nos.CA518099049 and PS 180060016
文摘During spawning events, horseshoe crab eggs are released from the female＇s oviducts, and fertilized by one or more males. Eggs are shaped by the female into discrete clutches deposited in nests at depths of 10-20 cm on intertidal estuarine beaches. Distinguishing between fxesh eggs and the early developmental stages is obfuscated by the large amount of dense, opaque yolk. The first unambiguous confirmation of development is the formation of the rudimentary prosomatie appendages at the ＂limb bud＂ stage. Several days thereafter, the outer chorion is shed and the developing embryo expands and undergoes a series of molts within the clear inner egg membrane. The trilobite （first iustar） stage thus attained may remain within the beach sedi- ments for several more weeks, until hatching is facilitated by environmental factors such as hydration, agitation, and osmotic shock that accompany the infiltration of seawater into the nests. Trilobites exhibit endogenous eirgatidal swimming rhythms that are entrained by mechanical agitation, suggesting that peaks in larval swimming are timed to coincide with periods of high water and the inundation of the nests. Larval swimming is limited and does not appear to result in long-distance dispersal. The limited dispersal of the larvae has important implications for the population dynamics of relatively isolated populations. The rate of larval development is highly plastic and is influenced by temperature, salinity, dissolved oxygen, and the presence of pollutants. The broad environmental tolerances of horseshoe crab embryos and larvae are important in understanding their current geographic distribution and their evolutionary persistence
基金Supported by the Key Laboratory of Experimental Marine Biology,Academia Sinica,Qingdao,Chinathe National High Technology Research and Development Program of China(863 Program)(No.2006AA10AA402)+1 种基金the National Basic Research Program of China(973Program)(Nos.2004CB117402,2010CB126304)the National Natural Science Foundation of China(No.30871929)
文摘MyoD, Myf5, and myogenin are myogenic regulatory factors that play important roles during myogenesis. It is thought that MyoD and Myf5 are required for myogenic determination, while myogenin is important for terminal differentiation and lineage maintenance. To better understand the function of myogenic regulatory factors in muscle development of flounder, an important economic fish in Asia, real-time quantitative RT-PCR was used to characterize the expression patterns of MyoD, Myf5, and myogenin at early stages of embryo development, and in different tissues of the adult flounder. The results show that, MyJ5 is the first gene to be expressed during the early stages of flounder development, followed by MyoD and myogenin. The expressions ofMyf5, MyoD, and myogenin at the early stages have a common characteristic： expression gradually increased to a peak level, and then gradually decreased to an extremely low level. In the adult flounder, the expression of the three genes in muscle is much higher than that in other tissues, indicating that they are important for muscle growth and maintenance of grown fish. During embryonic stages, the expression level of MyoD might serve an important role in the balance between muscle cell differentiation and proliferation. When the MyoD expression is over 30% of its highest level, the muscle cells enter the differentiation stage.
基金supported by the National Natural Science Foundation of China (31101875)the Specialized Research Fund for the Doctoral Program of Higher Education of China (20110132120027)
文摘To investigate the effects of elevated seawater p CO_2 on the early developmental stages of marine benthic calcifying organisms, we exposed the eggs and larvae of Argopecten irradias, an important bivalve species in Chinese aquaculture, in seawater equilibrated with CO_2-enriched(1000 ppm) gas mixtures. We demonstrated that elevated seawater pCO_2 significantly interfered with fertilization and larval development and resulted in an increased aberration rate. Fertilization in the treatment(pH 7.6) was 74.3% ± 3.8%, which was 9.7% lower than that in the control(p H 8.3)(84.0% ±3.0%). Hatching success decreased by 23.7%, and aberration rate increased by 30.3% under acidic condition. Larvae in acidified seawater still developed a shell during the post-embryonic phase. However, the shell length and height in the treatment were smaller than those in the control. The development of embryos differed significantly at 12 h after fertilization between the two experimental groups. Embryos developed slower in acidified seawater. Nearly half of the embryos in the control developed into D-shaped larvae at 48 h after fertilization, which were considerably more than those in the treatment(11.7%). Results suggest that future ocean acidification(OA) would cause detrimental effects on the early development of A. irradias.
基金supported by the Chinese Ministry of Science and Technology(2015CB964501 and2014CB964903)the National Natural Science Foundation of China(31371477)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA01020301)
文摘Mammalian cortical development is a dynamically and strictly regulated process orchestrated by extracellular signals and intracellular mechanisms. Recent studies show that epigenetic regulation serves as, at least in part, interfaces between genes and the environment, and also provides insight into the molecular and cellular bases of early embryonic cortical development. It is becoming increasingly clear that epigenetic regulation of cortical development occurs at multiple levels and that comprehensive knowledge of this complex regulatory landscape is essential to delineating embryonic neurogenesis.
