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
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
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 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.
