As in vertebrates, brains play key roles in rhythmic regulation, neuronal maintenance, diff erentiation and function, and control of the release of hormones in arthropods. But the structure and functional domains of t...As in vertebrates, brains play key roles in rhythmic regulation, neuronal maintenance, diff erentiation and function, and control of the release of hormones in arthropods. But the structure and functional domains of the brain are still not very clear in crustaceans. In the present study, we reveal the structural details of the brain in the redclaw crayfish using hematoxylin-eosin staining and microscopic examination, firstly. The brain of crayfish is consist of three main parts, namely, protocerebrum, deutocerebrum, and tritocerebrum, including some tracts and commissures, briefly. Secondly, at least 9 kinds of brain cells were identified on the basis of topology and cell shapes, as well as antibody labeling. We also provide morphological details of most cell types, which were previously un-described. In general, four types of glia and three types of neurosecretory cells were described except cluster 9/11 and cluster 10 cells. Glia were categorized into another three main kinds:(1) surface glia;(2) cortex glia; and(3) neuropile glia in addition to astrocytes identified by GFAP labelling. And neurosecretory cells were categorized into I, Ⅱ and III types based on morphological observation. Finally, cluster 9/11 and 10 cells derived from the brain of crayfish, could be used for primary culture about 7–9 d under the optimized conditions. There results provide a resource for improving the knowledge of the still incompletely defined neuroendocrinology of this species. Using the crayfish as an animal model, we are easy to carry out further research in manipulating their endocrine system, exploring cellular and synaptic mechanisms so much as larval production on a small scale, such as in a cell or tissue.展开更多
There were two species of crayfish “red-claw” (Cherax quadricarinatus) and “blue-huna” (Cherax albertisii) for their aquaculture potential. Crayfish were susceptible to fungal (crawfish plague), parasitic (protozo...There were two species of crayfish “red-claw” (Cherax quadricarinatus) and “blue-huna” (Cherax albertisii) for their aquaculture potential. Crayfish were susceptible to fungal (crawfish plague), parasitic (protozoa and nematodes), and bacterial pathogen. A number of ectosymbiont Craspedella sp. have been observed on red-claw and blue-huna. The flatworms were commonly found almost in the whole body, on the upper exoskeleton behind the head, in the gill cavity and on the claws and underside of crayfish. Although their number sometimes was very high, they didn’t cause any problems especially for the new molting crayfish. Micro organisms living on the crayfish surface body and worms didn’t cause any pathological changes. Adults Craspedella sp. can be eliminated by a short bath in salt water or formaldehyde 37% solutions for several hours. This treatment didn’t kill worm eggs, so it needs to be repeated every one week. Moreover, hyposalinity or OST (Osmotic Shock Therapy) is one of the most effective therapies for ectoparasites on Craspedella sp. with dose of bath treatment 15 grams per litre of salt (15 ppt) for more than 3 hours, and dipped in salt water at 30 ppt (or 3.0 ppm, seawater salinity) for 15 - 20 minutes.展开更多
Abstract The digestive enzyme activity and mRNA level of trypsin during the embryonic development of Cherax quadricarinatus were analyzed using biochemical and Fluorogenic Quantitative PCR （FQ-PCR） methods. The resu...Abstract The digestive enzyme activity and mRNA level of trypsin during the embryonic development of Cherax quadricarinatus were analyzed using biochemical and Fluorogenic Quantitative PCR （FQ-PCR） methods. The results show that the activities of trypsin and chymotrypsin had two different change patterns. Trypsin specific activity increased rapidly in the early stages of development and still remained high in preparation for the hatch stage. However, chymotrypsin activity peaked in stage 4 of embryonic development and decreased significantly in the last stage. The mRNA level of trypsin was elevated in all stages and two peak values were observed in stages 2 and 5 respectively. The results indicate that trypsin is very important for the utilization of the yolk during embryonic development and for the assimilation of dietary protein for larvae. The gene of trypsin is probably regulated at transcriptional level. The mRNA levels of trypsin can reflect not only trypsin activity, but also the regulatory mechanism for expression of trypsin gene to a certain degree.展开更多
The compound eye evolved over 500 million years ago and enables mosaic vision in most arthropod species.The molecular regulation of the development of the compound eye has been primarily studied in the fruit fly Droso...The compound eye evolved over 500 million years ago and enables mosaic vision in most arthropod species.The molecular regulation of the development of the compound eye has been primarily studied in the fruit fly Drosophila melanogaster.However,due to the nature of holometabolous insects halting growth after their terminal metamorphosis into the adult form,they lack the capacity to regenerate.Crustaceans,unlike holometabolous insects,continue to grow during adulthood,achieved through regular shedding of their exoskeleton,in a cyclic process known as molting.This therefore offers crustaceans as a highly suitable model to study ocular regeneration in the adult arthropod eye.We have assessed the regenerative capacity of the retinal section of the Cherax quadricarinatus(red-claw crayfish)eye,following ablation and successive post-metamorphic molts.This work then provides a transcriptomic description of the outer,pigmented retinal tissue(the ommatidia and lamina ganglionaris)and the basal,non-pigmented neuroendocrine ocular tissue(the X-organ Sinus Gland complex,hemiellipsoid body and optic nerve).Using comparative analysis,we identified all the transcripts in the C.quadricarinatus ocular transcriptome that are known to function in compound eye development in D.melanogaster.Differentially and uniquely transcribed genes of the retina are described,suggesting proposed mechanisms that may regulate ocular regeneration in decapod Crustacea.This research exemplifies the application C.quadricarinatus holds as an optimal model to study the regulation of ocular regeneration.Further in-depth transcriptomic analyses are now required,sampled throughout the regeneration process to better define the regulatory mechanism.展开更多
The phylogenetic relationships among imported ornamental crayfish belonging to the genus Cherax were inferred from a combined dataset of 3 mitochondrial genes(COI,16S and 12S)and by comparison with availab...The phylogenetic relationships among imported ornamental crayfish belonging to the genus Cherax were inferred from a combined dataset of 3 mitochondrial genes(COI,16S and 12S)and by comparison with available GenBank sequences of 14 Cherax species.Furthermore,the concordance of previously described species obtained from a wholesaler(Cherax boesemani,C.holthuisi and C.peknyi)with available GenBank sequences was verified based on COI with special respect to comparison with sequences assigned as Cherax species.Recently described species C.gherardiae,C.pulcher and C.subterigneus belong to the northern group of Cherax species.Comparison and analysis with other GenBank COI sequences show previously unreported diversity of New Guinean species,suggesting 5 putative new species.Surprisingly,species assigned to the subgenus Astaconephrops do not form a monophyletic clade;this subgenus should be reappraised relative to the purported typical morphological characteristic of the uncalcified patch on male chelae.Increasing importation of crayfish underscores the importance of accurate species identification.Use of basic molecular methods is a necessary requisite for documenting occurrence,abundance and population trends of target species.Consequently,it helps to support eventual conservation decision-making by stakeholders.展开更多
基金Supported by the National Natural Science Foundation of China(No.41376165)the National Natural Science Foundation of ChinaIsrael Science Foundation(NSFC-ISF)(No.31461143007)the Scientific and Technological Innovation Project financially supported by Qingdao National Laboratory for Marine Science and Technology(No.2015ASKJ02)
文摘As in vertebrates, brains play key roles in rhythmic regulation, neuronal maintenance, diff erentiation and function, and control of the release of hormones in arthropods. But the structure and functional domains of the brain are still not very clear in crustaceans. In the present study, we reveal the structural details of the brain in the redclaw crayfish using hematoxylin-eosin staining and microscopic examination, firstly. The brain of crayfish is consist of three main parts, namely, protocerebrum, deutocerebrum, and tritocerebrum, including some tracts and commissures, briefly. Secondly, at least 9 kinds of brain cells were identified on the basis of topology and cell shapes, as well as antibody labeling. We also provide morphological details of most cell types, which were previously un-described. In general, four types of glia and three types of neurosecretory cells were described except cluster 9/11 and cluster 10 cells. Glia were categorized into another three main kinds:(1) surface glia;(2) cortex glia; and(3) neuropile glia in addition to astrocytes identified by GFAP labelling. And neurosecretory cells were categorized into I, Ⅱ and III types based on morphological observation. Finally, cluster 9/11 and 10 cells derived from the brain of crayfish, could be used for primary culture about 7–9 d under the optimized conditions. There results provide a resource for improving the knowledge of the still incompletely defined neuroendocrinology of this species. Using the crayfish as an animal model, we are easy to carry out further research in manipulating their endocrine system, exploring cellular and synaptic mechanisms so much as larval production on a small scale, such as in a cell or tissue.
文摘There were two species of crayfish “red-claw” (Cherax quadricarinatus) and “blue-huna” (Cherax albertisii) for their aquaculture potential. Crayfish were susceptible to fungal (crawfish plague), parasitic (protozoa and nematodes), and bacterial pathogen. A number of ectosymbiont Craspedella sp. have been observed on red-claw and blue-huna. The flatworms were commonly found almost in the whole body, on the upper exoskeleton behind the head, in the gill cavity and on the claws and underside of crayfish. Although their number sometimes was very high, they didn’t cause any problems especially for the new molting crayfish. Micro organisms living on the crayfish surface body and worms didn’t cause any pathological changes. Adults Craspedella sp. can be eliminated by a short bath in salt water or formaldehyde 37% solutions for several hours. This treatment didn’t kill worm eggs, so it needs to be repeated every one week. Moreover, hyposalinity or OST (Osmotic Shock Therapy) is one of the most effective therapies for ectoparasites on Craspedella sp. with dose of bath treatment 15 grams per litre of salt (15 ppt) for more than 3 hours, and dipped in salt water at 30 ppt (or 3.0 ppm, seawater salinity) for 15 - 20 minutes.
基金Supported by the NNSF of China (No.30670227)hanghai Agricultural Science & Technology Key Grant [6-1(2006)].
文摘Abstract The digestive enzyme activity and mRNA level of trypsin during the embryonic development of Cherax quadricarinatus were analyzed using biochemical and Fluorogenic Quantitative PCR （FQ-PCR） methods. The results show that the activities of trypsin and chymotrypsin had two different change patterns. Trypsin specific activity increased rapidly in the early stages of development and still remained high in preparation for the hatch stage. However, chymotrypsin activity peaked in stage 4 of embryonic development and decreased significantly in the last stage. The mRNA level of trypsin was elevated in all stages and two peak values were observed in stages 2 and 5 respectively. The results indicate that trypsin is very important for the utilization of the yolk during embryonic development and for the assimilation of dietary protein for larvae. The gene of trypsin is probably regulated at transcriptional level. The mRNA levels of trypsin can reflect not only trypsin activity, but also the regulatory mechanism for expression of trypsin gene to a certain degree.
基金This work was supported by funding from the Bright Focus Foundationa Ramaciotti Establishment Grant to AWH.
文摘The compound eye evolved over 500 million years ago and enables mosaic vision in most arthropod species.The molecular regulation of the development of the compound eye has been primarily studied in the fruit fly Drosophila melanogaster.However,due to the nature of holometabolous insects halting growth after their terminal metamorphosis into the adult form,they lack the capacity to regenerate.Crustaceans,unlike holometabolous insects,continue to grow during adulthood,achieved through regular shedding of their exoskeleton,in a cyclic process known as molting.This therefore offers crustaceans as a highly suitable model to study ocular regeneration in the adult arthropod eye.We have assessed the regenerative capacity of the retinal section of the Cherax quadricarinatus(red-claw crayfish)eye,following ablation and successive post-metamorphic molts.This work then provides a transcriptomic description of the outer,pigmented retinal tissue(the ommatidia and lamina ganglionaris)and the basal,non-pigmented neuroendocrine ocular tissue(the X-organ Sinus Gland complex,hemiellipsoid body and optic nerve).Using comparative analysis,we identified all the transcripts in the C.quadricarinatus ocular transcriptome that are known to function in compound eye development in D.melanogaster.Differentially and uniquely transcribed genes of the retina are described,suggesting proposed mechanisms that may regulate ocular regeneration in decapod Crustacea.This research exemplifies the application C.quadricarinatus holds as an optimal model to study the regulation of ocular regeneration.Further in-depth transcriptomic analyses are now required,sampled throughout the regeneration process to better define the regulatory mechanism.
基金supported by CIGA(project no.20152007)the Ministry of Education,Youth and Sports of the Czech Republic(projects“CENAKVA”[no.CZ.1.05/2.1.00/01.0024]+1 种基金“CENAKVA II”[no.LO1205 under the NPU I program]and“The Development of Postdoc Positions at the USB”[no.CZ.1.07/2.3.00/30.0049]Partial funding was provided by the Czech Science Foundation through project P502/12/P177.
文摘The phylogenetic relationships among imported ornamental crayfish belonging to the genus Cherax were inferred from a combined dataset of 3 mitochondrial genes(COI,16S and 12S)and by comparison with available GenBank sequences of 14 Cherax species.Furthermore,the concordance of previously described species obtained from a wholesaler(Cherax boesemani,C.holthuisi and C.peknyi)with available GenBank sequences was verified based on COI with special respect to comparison with sequences assigned as Cherax species.Recently described species C.gherardiae,C.pulcher and C.subterigneus belong to the northern group of Cherax species.Comparison and analysis with other GenBank COI sequences show previously unreported diversity of New Guinean species,suggesting 5 putative new species.Surprisingly,species assigned to the subgenus Astaconephrops do not form a monophyletic clade;this subgenus should be reappraised relative to the purported typical morphological characteristic of the uncalcified patch on male chelae.Increasing importation of crayfish underscores the importance of accurate species identification.Use of basic molecular methods is a necessary requisite for documenting occurrence,abundance and population trends of target species.Consequently,it helps to support eventual conservation decision-making by stakeholders.
