Neurological disorders are diseases of the central and peripheral nervous systems.These disorders include Alzheimer＇s disease,epilepsy,brain tumor,and cerebrovascular diseases（stroke,migraine and other headache diso...Neurological disorders are diseases of the central and peripheral nervous systems.These disorders include Alzheimer＇s disease,epilepsy,brain tumor,and cerebrovascular diseases（stroke,migraine and other headache disorders,multiple sclerosis,Parkinson＇s disease,and neuroinfections）.展开更多
Peripheral nerve injuries are often caused by trauma and they may result in a partial or total loss of motor function or sensory perception. After nerve injuries, peripheral axons have the ability to regenerate and re...Peripheral nerve injuries are often caused by trauma and they may result in a partial or total loss of motor function or sensory perception. After nerve injuries, peripheral axons have the ability to regenerate and reconnect the proximal and distal ends of severed nerve axons if the nerve gap is small. For larger nerve gaps, surgical treatments are often required to repair the injured nerves.展开更多
RNA in situ hybridization （ISH）, including chromogenic ISH （CISH） and fluorescent ISH （FISH）, has become a powerful tool for revealing the spatial distribution ofgene transcripts in model organisms. Previously, ...RNA in situ hybridization （ISH）, including chromogenic ISH （CISH） and fluorescent ISH （FISH）, has become a powerful tool for revealing the spatial distribution ofgene transcripts in model organisms. Previously, we developed a robust protocol for wholemount RNA CISH in the pea aphid Acyrthosiphon pisum, an emerging insect genomicmodel. In order to improve the resolving capacity of gene detection, we comprehensively surveyed current protocols of whole-mount RNA-FISH and developed protocols that allow,using confocal microscopy, clearer visualization of target messenger RNAs （mRNAs） - including those subcellularly localized and those with spatially overlapping expression. Wefind that Fast dye-based substrate fluorescence （SF）, tyramide signal amplification （TSA）, and TSA Plus all enable identifying gene expression thanks to multiplex amplificationof fluorescent signals. By contrast, methods of direct fluorescence （DF） do not allow visualizing signals. Detection of a single gene target was achieved with SF and TSA Plusfor most mRNAs, whereas TSA only allowed visualization of abundant transcripts such as Apvasl andAppiwi2 in the germ cells. For detection of multiple gene targets using doubleFISH, we recommend： （i） TSA/TSA, rather than TSA Plus/TSA Plus for colocalized mRNAs abundantly expressed in germ ceils, as proteinase K treatment can be omitted;and （ii） SF/TSA Plus for other gene targets such as Apenl and Apen2 as inactivation of enzyme conjugates is not required. SF/SF is not ideal for double FISH experiments due tosignal blurring. Based on these new conditions for RNA-FISH, we have obtained a better understanding of germline specification and embryonic segmentation in the pea aphid.We anticipate that the RNA-FISH protocols for the pea aphid may also be used for other aphids and possibly other insect species, thus expanding the range of species from whichuseful insights into development and evolution may be obtained.展开更多
Studies of the living embryo sacs of Torenia fournieri reveal that the actin cytoskeleton undergoes dramatic changes that correlate with nuclear migration within the central cell and the primary endosperm. Before poll...Studies of the living embryo sacs of Torenia fournieri reveal that the actin cytoskeleton undergoes dramatic changes that correlate with nuclear migration within the central cell and the primary endosperm. Before pollination, actin filaments appear as short bundles randomly distributed in the cortex of the central cell. Two days after anthesis, they become organized into a distinct actin network. At this stage the secondary nucleus, which is located in the central region of the central cell, possesses an associated array of short actin filaments. Soon after pollination, the actin filaments become fragmented in the micropylar end and the secondary nucleus is located next to the egg apparatus. After fertilization, the primary endosperm nucleus moves away from the egg cell and actin filaments reorganize into a prominent network in the cytoplasm of the primary endosperm. Disruption of the actin cytoskeleton with latrunculin A and cytochalasin B indicates that actin is involved in the migration of the nucleus in the central cell. Our data also suggest that the dynamics of actin cytoskeleton may be responsible for the reorganization of the central cell and primary endosperm cytoplasm during fertilization.展开更多
文摘Neurological disorders are diseases of the central and peripheral nervous systems.These disorders include Alzheimer＇s disease,epilepsy,brain tumor,and cerebrovascular diseases（stroke,migraine and other headache disorders,multiple sclerosis,Parkinson＇s disease,and neuroinfections）.
文摘Peripheral nerve injuries are often caused by trauma and they may result in a partial or total loss of motor function or sensory perception. After nerve injuries, peripheral axons have the ability to regenerate and reconnect the proximal and distal ends of severed nerve axons if the nerve gap is small. For larger nerve gaps, surgical treatments are often required to repair the injured nerves.
文摘RNA in situ hybridization （ISH）, including chromogenic ISH （CISH） and fluorescent ISH （FISH）, has become a powerful tool for revealing the spatial distribution ofgene transcripts in model organisms. Previously, we developed a robust protocol for wholemount RNA CISH in the pea aphid Acyrthosiphon pisum, an emerging insect genomicmodel. In order to improve the resolving capacity of gene detection, we comprehensively surveyed current protocols of whole-mount RNA-FISH and developed protocols that allow,using confocal microscopy, clearer visualization of target messenger RNAs （mRNAs） - including those subcellularly localized and those with spatially overlapping expression. Wefind that Fast dye-based substrate fluorescence （SF）, tyramide signal amplification （TSA）, and TSA Plus all enable identifying gene expression thanks to multiplex amplificationof fluorescent signals. By contrast, methods of direct fluorescence （DF） do not allow visualizing signals. Detection of a single gene target was achieved with SF and TSA Plusfor most mRNAs, whereas TSA only allowed visualization of abundant transcripts such as Apvasl andAppiwi2 in the germ cells. For detection of multiple gene targets using doubleFISH, we recommend： （i） TSA/TSA, rather than TSA Plus/TSA Plus for colocalized mRNAs abundantly expressed in germ ceils, as proteinase K treatment can be omitted;and （ii） SF/TSA Plus for other gene targets such as Apenl and Apen2 as inactivation of enzyme conjugates is not required. SF/SF is not ideal for double FISH experiments due tosignal blurring. Based on these new conditions for RNA-FISH, we have obtained a better understanding of germline specification and embryonic segmentation in the pea aphid.We anticipate that the RNA-FISH protocols for the pea aphid may also be used for other aphids and possibly other insect species, thus expanding the range of species from whichuseful insights into development and evolution may be obtained.
基金This research was supported by a RGC grant from the Research Grants Council of Hong Kong anda CRCG grant from University of Hong Kong to B. Q. H, a CRCG grant to S. Y. Z, NSF grant No. MCB-9601087 to P. K. H., and the National Key Basic Research Projec
文摘Studies of the living embryo sacs of Torenia fournieri reveal that the actin cytoskeleton undergoes dramatic changes that correlate with nuclear migration within the central cell and the primary endosperm. Before pollination, actin filaments appear as short bundles randomly distributed in the cortex of the central cell. Two days after anthesis, they become organized into a distinct actin network. At this stage the secondary nucleus, which is located in the central region of the central cell, possesses an associated array of short actin filaments. Soon after pollination, the actin filaments become fragmented in the micropylar end and the secondary nucleus is located next to the egg apparatus. After fertilization, the primary endosperm nucleus moves away from the egg cell and actin filaments reorganize into a prominent network in the cytoplasm of the primary endosperm. Disruption of the actin cytoskeleton with latrunculin A and cytochalasin B indicates that actin is involved in the migration of the nucleus in the central cell. Our data also suggest that the dynamics of actin cytoskeleton may be responsible for the reorganization of the central cell and primary endosperm cytoplasm during fertilization.
