Showing 111 - 120 of 257 Items
Molecular and mass spectral identification of the broadly conserved decapod crustacean neuropeptide pQIRYHQCYFNPISCF: The first PISCF-allatostatin (Manduca sexta- or C-type allatostatin) from a non-insect
Date: 2010-01-01
Creator: Elizabeth A. Stemmler, Emily A. Bruns, Christopher R. Cashman, Patsy S. Dickinson, Andrew E., Christie
Access: Open access
- The PISCF-allatostatins (Manduca sexta- or C-type allatostatins) are a family of pentadecapeptides characterized by a pyroglutamine blocked N-terminus, an unamidated-PISCF C-terminus, and a disulfide bridge between two internal Cys residues. Several isoforms of PISCF-AST are known, all from holometabolous insects. Using a combination of transcriptomics and mass spectrometry, we have identified the first PISCF-type peptides from a non-insect species. In silico analysis of crustacean ESTs identified several Litopenaeus vannamei (infraorder Penaeidea) transcripts encoding putative PISCF-AST precursors. Translation of these ESTs, with subsequent prediction of their putative post-translational processing, revealed the existence of as many as three PISCF-type peptides, including pQIRYHQCYFNPISCF (disulfide bridging between Cys7 and Cys14). Although none of the predicted isoforms was detected by mass spectrometry in L. vannamei, MALDI-FTMS mass profiling identified an m/z signal corresponding to pQIRYHQCYFNPISCF (disulfide bridge present) in neural tissue from 28 other decapods, which included members of six infraorders (Stenopodidea, Astacidea, Thalassinidea, Achelata, Anomura and Brachyura). Further characterization of the peptide using SORI-CID and chemical derivatization/enzymatic digestion supported the theorized structure. In both the crab Cancer borealis and the lobster Homarus americanus, MALDI-based tissue surveys suggest that pQIRYHQCYFNPISCF is broadly distributed in the nervous system; it was also detected in the posterior midgut caecum. Collectively, our data show that members of the PISCF-AST family are not restricted to the holometabolous insects, but instead may be broadly conserved within the Pancrustacea. Moreover, our data suggest that one highly conserved PISCF-type peptide, pQIRYHQCYFN-PISCF, is present in decapod crustaceans, functioning as a brain-gut paracrine/hormone. © 2009 Elsevier Inc. All rights reserved.
To what extent may peptide receptor gene diversity/complement contribute to functional flexibility in a simple pattern-generating neural network?
Date: 2019-06-01
Creator: Patsy S. Dickinson, J. Joe Hull, Alexandra Miller, Emily R. Oleisky, Andrew E., Christie
Access: Open access
- Peptides are known to contribute to central pattern generator (CPG) flexibility throughout the animal kingdom. However, the role played by receptor diversity/complement in determining this functional flexibility is not clear. The stomatogastric ganglion (STG) of the crab, Cancer borealis, contains CPGs that are models for investigating peptidergic control of rhythmic behavior. Although many Cancer peptides have been identified, their peptide receptors are largely unknown. Thus, the extent to which receptor diversity/complement contributes to modulatory flexibility in this system remains unresolved. Here, a Cancer mixed nervous system transcriptome was used to determine the peptide receptor complement for the crab nervous system as a whole. Receptors for 27 peptide families, including multiple receptors for some groups, were identified. To increase confidence in the predicted sequences, receptors for allatostatin-A, allatostatin-B, and allatostatin-C were cloned, sequenced, and expressed in an insect cell line; as expected, all three receptors trafficked to the cell membrane. RT-PCR was used to determine whether each receptor was expressed in the Cancer STG. Transcripts for 36 of the 46 identified receptors were amplified; these included at least one for each peptide family except RYamide. Finally, two peptides untested on the crab STG were assessed for their influence on its motor outputs. Myosuppressin, for which STG receptors were identified, exhibited clear modulatory effects on the motor patterns of the ganglion, while a native RYamide, for which no STG receptors were found, elicited no consistent modulatory effects. These data support receptor diversity/complement as a major contributor to the functional flexibility of CPGs.
Waterfowl habitat change over five decades in a freshwater tidal ecosystem in mid-coast maine
Date: 2011-01-01
Creator: J. Lichter, M.E.H. Burton, S.L. Close, J.M. Grinvalsky, J., Reblin
Access: Open access
Differential gene expression during compensatory sprouting of dendrites in the auditory system of the cricket Gryllus bimaculatus
Date: 2009-08-01
Creator: H. W. Horch, S. S. McCarthy, S. L. Johansen, J. M. Harris
Access: Open access
- Neurones that lose their presynaptic partners because of injury usually retract or die. However, when the auditory interneurones of the cricket Gryllus bimaculatus are denervated, dendrites respond by growing across the midline and forming novel synapses with the opposite auditory afferents. Suppression subtractive hybridization was used to detect transcriptional changes 3 days after denervation. This is a stage at which we demonstrate robust compensatory dendritic sprouting. Whereas 49 unique candidates were down-regulated, no sufficiently up-regulated candidates were identified at this time point. Several candidates identified in this study are known to influence the translation and degradation of proteins in other systems. The potential role of these factors in the compensatory sprouting of cricket auditory interneurones in response to denervation is discussed. © 2009 The Royal Entomological Society.
To hum or not to hum: analyzing and provoking sound production in the American lobster (Homarus americanus)
Date: 2024-01-01
Creator: Renske Kerkhofs
Access: Open access
- American lobsters (Homarus americanus) produce humming sounds by vibrating their carapace. These sounds have a fundamental frequency on the order of 100 Hz, with multiple higher harmonics. Though I found no relationship between lobster carapace length and hum frequency, I observed sounds similarly structured to hums but with frequencies an order of magnitude higher, suggesting that lobsters may use a wider range of sounds than previously thought. Using laser vibrometry, I was able to pick up high frequencies of carapace vibration that were similar to those I observed on sound recordings. Lobsters seem to hum most readily when approached from above, but many studies have found it difficult to reliably find soniferous lobsters. To find a way to reliably evoke sound production in American lobsters without contributing to the sound environment, lobsters were exposed to overhead abstract visual stimuli on a screen, after which their behavioral reactions were recorded, as well as any sound production in response to the stimulus. Lobsters responded to the screen stimulus with the same types of behaviors with which they responded to general overhead physical stimuli. This study demonstrates that American lobsters may produce high-pitched sounds and that abstract visual cues can be used as a silent tool to elicit lobster behaviors, but not sound production.
Requirement for pectin methyl esterase and preference for fragmented over native pectins for wall-associated kinase-activated, EDS1/PAD4-dependent stress response in arabidopsis
Date: 2014-07-04
Creator: Bruce D. Kohorn, Susan L. Kohorn, Nicholas J. Saba, Victoriano Meco Martinez
Access: Open access
- Background: The wall-associated kinases (WAKs) serve as pectin receptors. Results: A pectin methyl esterase and two transcription factor mutants suppress a dominant WAK allele. Conclusion: De-esterification of pectin is required for WAK activation though EDS1 and PAD4. Significance: The results provide a mechanism for the state of pectins to activate two different pathways. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.
Eelgrass meadow structure drives epifaunal community composition more than temperature during a Marine Heat Wave in the Gulf of Maine This record is embargoed.
- Embargo End Date: 2029-05-16
Date: 2024-01-01
Creator: Nicholas Takaki Tienhui Yoong
Access: Embargoed
Changes in chiropteran community structure associated with the white-nose syndrome epidemic: evidence for competitive release? Access to this record is restricted to members of the Bowdoin community. Log in here to view.
Date: 2014-05-01
Creator: Adam Eichenwald
Access: Access restricted to the Bowdoin Community
Disease on the Half-Shell: Prevalence and impact of the protistan pathogen MSX on oyster population health throughout the Gulf of Maine Access to this record is restricted to members of the Bowdoin community. Log in here to view.
Date: 2018-05-01
Creator: Madeline Schuldt
Access: Access restricted to the Bowdoin Community
Enhancer usage variation assessed via chromatin-conformation within and among three species of Drosophila This record is embargoed.
- Embargo End Date: 2027-05-19
Date: 2022-01-01
Creator: Maia B. Granoski
Access: Embargoed