Project description:Background: Responses to hypoxia have been investigated in many species; however, comparative study between conspecific geographical populations in different altitude regions is rare, especially for invertebrates . The migratory locust, Locusta migratoria, is widely distributed both on high-altitude Tibetan Plateau (TP) and on low-altitude North China Plain (NP). TP locusts have inhabited Tibetan Plateau since Quaternary glaciations events and thus probably have evolved superior capacity to deal with hypoxia. Results: Here we compared the hypoxic responses of TP and NP locusts from morphological, behavioral and physiological perspectives. We found that TP locusts were more tolerant of extreme hypoxia than NP locusts, with a lower proportion exhibiting stupor, a faster recovery time, and higher respiration rates. We compared the transcriptional profiles of field TP and NP locusts and found that their differences were possibly attributed to a combination of multiple factors, e.g. oxygen, UV radiation, temperature and nutrition. To evaluate why TP locusts respond to extreme hypoxia differently from NP locusts, we subjected them to extreme hypoxia and compared their transcriptional responses. We found that the aerobic metabolism was more active in TP locusts than in NP locusts. RNAi disruption of PDHE1b, an entry gene from glycolysis to TCA cycle, increased the ratio of stupor in Tibetan locusts and decreased the ATP content of Tibetan locusts in hypoxia, confirming the significant importance of this metabolic branch for TP locusts to conquer hypoxia. Conclusions: Here we show that TP locusts are better tolerant of hypoxia than NP locusts and the better capacity to modulate primary metabolism in TP locusts contributes to their superior tolerance of hypoxia compared to NP locusts. FIELD POPULATION: TP locusts vs. NP locusts;direct comparison on 6 separate microarrays; each microarray compares one biological replicate; each biological replicate contains 10 individuals. LAB POPULATION: hypoxia-treated TP locusts vs TP locusts in normoxia; hypoxia-treated NP locusts vs NP locusts in normoxia; direct comparison on 6 separate microarrays; each microarray compares one biological replicate; each biological replicate contains 10 individuals.
Project description:Background: Responses to hypoxia have been investigated in many species; however, comparative study between conspecific geographical populations in different altitude regions is rare, especially for invertebrates . The migratory locust, Locusta migratoria, is widely distributed both on high-altitude Tibetan Plateau (TP) and on low-altitude North China Plain (NP). TP locusts have inhabited Tibetan Plateau since Quaternary glaciations events and thus probably have evolved superior capacity to deal with hypoxia. Results: Here we compared the hypoxic responses of TP and NP locusts from morphological, behavioral and physiological perspectives. We found that TP locusts were more tolerant of extreme hypoxia than NP locusts, with a lower proportion exhibiting stupor, a faster recovery time, and higher respiration rates. We compared the transcriptional profiles of field TP and NP locusts and found that their differences were possibly attributed to a combination of multiple factors, e.g. oxygen, UV radiation, temperature and nutrition. To evaluate why TP locusts respond to extreme hypoxia differently from NP locusts, we subjected them to extreme hypoxia and compared their transcriptional responses. We found that the aerobic metabolism was more active in TP locusts than in NP locusts. RNAi disruption of PDHE1b, an entry gene from glycolysis to TCA cycle, increased the ratio of stupor in Tibetan locusts and decreased the ATP content of Tibetan locusts in hypoxia, confirming the significant importance of this metabolic branch for TP locusts to conquer hypoxia. Conclusions: Here we show that TP locusts are better tolerant of hypoxia than NP locusts and the better capacity to modulate primary metabolism in TP locusts contributes to their superior tolerance of hypoxia compared to NP locusts.
Project description:We report the application of single-molecule-based sequencing technology for high-throughput profiling of nervous system in locust Locusta migratoria manilensis. By obtaining over 57,000,000 bases of sequence from central nervous system, we generated 101836 contigs and 69440 scaffolds. We finally get 41179 unigene with an average length of 570bp. There are 5519 unigenes beyond the length of 1000bp. Using BLAST searches of the NR, NT, Swiss-Prot, KEGG and COG databases we are able to identify 13552 unigene (E<0.0001). Comprehensive assessment of all the unigenes by comparing with the studied genes of other insects nervous system reveals that our unigene are broadly representative of the transcriptome of insect nervous system. Our data provides the most large-scale EST-project for locust nervous system, which greatly benefits the exploring of this insect. In addition, we identify a large number of novel nervous genes which can be used in systematic studies of locust and other insects.
Project description:The migratory locust, Locusta migratoria, is a serious agricultural pest and important insect model to study insect digestion and feeding behavior. The gut is one of the primary interfaces between the insect and its environment. Nevertheless, knowledge on the gut transcriptome of L. migratoria is still very limited. With the development of two EST databases from L. migratoria (whole body and central nervous system (CNS)) and one EST database from Schistocerca gregaria (CNS), an abundance of transcript data was made available for locusts. In addition, the genome of Locusta was also recently published in an effort to create a better understanding of swarm formation and flight behavior (Wang et al., 2014). While the transcript composition of nervous tissue was relatively well studied after the development of the specific CNS-derived EST-databases from both L. migratoria and S. gregaria, little transcript profiling information is available for the digestive system at the moment. Locusts are, however, widely used as physiological model organisms regarding the regulation and control of feeding and digestion, and improved knowledge on the gut transcriptome could contribute significantly to a better understanding of their gut physiology. Therefore, we aimed to use the available sequence data to specifically identify gut-expressed transcripts in 5th larval locusts. By means of two independent self-self microarray hybridizations for two distinct tissues, the gut and the brain, a selection could be made of those ESTs that are present in the gut and/or the brain. Here, sequences that were found to be expressed in gut but not brain were further functionally annotated to shed new light on the complex physiology of the locust digestive system. Since the gut is the single most important organ in digestion, and both tissues are assumed to be involved in the regulation thereof, the resulting subset of sequences can also be valuable for further in-depth studies on the regulation of digestion. In addition, the method allowed us to rank the signal intensities, using them as a rough indicator to compare relative transcript abundance in the gut. Therefore, the data complement previously published transcript and genomic data, and provide a clear overview of the expressed portion of the genome in the gut. Taken together, the present data provide significant insight into locust larval gut physiology, and will be valuable for future studies on the insect gut.
Project description:The migratory locust, Locusta migratoria, is a serious agricultural pest and important insect model to study insect digestion and feeding behavior. The gut is one of the primary interfaces between the insect and its environment. Nevertheless, knowledge on the gut transcriptome of L. migratoria is still very limited. With the development of two EST databases from L. migratoria (whole body and central nervous system (CNS)) and one EST database from Schistocerca gregaria (CNS), an abundance of transcript data was made available for locusts. In addition, the genome of Locusta was also recently published in an effort to create a better understanding of swarm formation and flight behavior (Wang et al., 2014). While the transcript composition of nervous tissue was relatively well studied after the development of the specific CNS-derived EST-databases from both L. migratoria and S. gregaria, little transcript profiling information is available for the digestive system at the moment. Locusts are, however, widely used as physiological model organisms regarding the regulation and control of feeding and digestion, and improved knowledge on the gut transcriptome could contribute significantly to a better understanding of their gut physiology. Therefore, we aimed to use the available sequence data to specifically identify gut-expressed transcripts in 5th larval locusts. By means of two independent self-self microarray hybridizations for two distinct tissues, the gut and the brain, a selection could be made of those ESTs that are present in the gut and/or the brain. Here, sequences that were found to be expressed in gut but not brain were further functionally annotated to shed new light on the complex physiology of the locust digestive system. Since the gut is the single most important organ in digestion, and both tissues are assumed to be involved in the regulation thereof, the resulting subset of sequences can also be valuable for further in-depth studies on the regulation of digestion. In addition, the method allowed us to rank the signal intensities, using them as a rough indicator to compare relative transcript abundance in the gut. Therefore, the data complement previously published transcript and genomic data, and provide a clear overview of the expressed portion of the genome in the gut. Taken together, the present data provide significant insight into locust larval gut physiology, and will be valuable for future studies on the insect gut. Self-self hybridisation of Cy5- and Cy3-labeled samples. One biological repeat per tissue type, i.e., brain and gut. Gut is a combination of foregut, midgut, gastric caeca and hindgut. Per tissue type, a pool was made from RNA from 3 pools of 5 locusts, and this for 3 different feeding conditions, resulting in samples derived from a total of 45 locust larvae. Feeding conditions were normally fed, fed with diet containing additional protease inhibitors (PIs), and starved locusts.
Project description:All the reports on insect small RNAs come from holometabolous insects. However, small RNAs of hemimetabolous insects have not yet been investigated.Study of hemimetabolous insect small RNAs could provide more insights into evolution and function of small RNAs in hemi- and holometabolous insects. The locust is an important, economically harmful hemimetabolous insect and its phase changes is an interesting phenomenon.Here, we used high-throughput sequencing to characterize and compare the small RNA transcriptomes of gregarious and solitary phases in locusts. We found abundant small RNAs and their different expression profiles in the two phases.
Project description:We report the application of single-molecule-based sequencing technology for high-throughput profiling of nervous system in locust Locusta migratoria manilensis. By obtaining over 57,000,000 bases of sequence from central nervous system, we generated 101836 contigs and 69440 scaffolds. We finally get 41179 unigene with an average length of 570bp. There are 5519 unigenes beyond the length of 1000bp. Using BLAST searches of the NR, NT, Swiss-Prot, KEGG and COG databases we are able to identify 13552 unigene (E<0.0001). Comprehensive assessment of all the unigenes by comparing with the studied genes of other insects nervous system reveals that our unigene are broadly representative of the transcriptome of insect nervous system. Our data provides the most large-scale EST-project for locust nervous system, which greatly benefits the exploring of this insect. In addition, we identify a large number of novel nervous genes which can be used in systematic studies of locust and other insects. Examination of 1 sample