Oocytes formation in post-diapause Neocalanus flemingeri females from the R/V Sikuliaq and the R/V Tiglax in Prince William Sound in the Gulf of Alaska from 2019-06-30 to 2019-09-13

Website: https://www.bco-dmo.org/dataset/908514
Data Type: Cruise Results, experimental
Version: 1
Version Date: 2023-09-17

Project
» Collaborative Research: Molecular profiling of the ecophysiology of dormancy induction in calanid copepods of the Northern Gulf of Alaska LTER site (Diapause preparation)
ContributorsAffiliationRole
Lenz, Petra H.University of Hawaii at Manoa (PBRC)Principal Investigator, Contact
Hartline, Daniel K.University of Hawaii at Manoa (PBRC)Scientist
Monell, Kira J.University of Hawaii at Manoa (PBRC)Scientist, Student, Data Manager
Merchant, Lynne M.Woods Hole Oceanographic Institution (WHOI BCO-DMO)BCO-DMO Data Manager

Abstract
These data are from a study on the formation of oocytes in post-diapause Neocalanus flemingeri females collected from depth in Prince William Sound in the Gulf of Alaska. Collections were made during two NGA LTER cruises. After sorting, females were incubated in flasks and removed for experimental incubations and imaging. Oocyte production by post-diapause females that involved DNA replication in the ovary and oviducts was examined using incubation in 5-Ethynyl-2’-deoxyuridine (EdU). Both oogonia and oocytes incorporated EdU, with the number of EdU labeled cells peaking at 72 hours following diapause termination. Cells labeling with EdU remained high for two weeks, decreasing thereafter with no labeling detected by four weeks post diapause, and three to four weeks before spawning of the first clutch of eggs. By limiting DNA replication to the initial phase, the females effectively separate oocyte production from oocyte provisioning.


Coverage

Spatial Extent: N:60.535 E:-147.803 S:60.278 W:-147.987

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Related Publications

Monell, K. J., Roncalli, V., Hopcroft, R. R., Hartline, D. K., & Lenz, P. H. (2023). Post-Diapause DNA Replication during Oogenesis in a Capital-Breeding Copepod. Integrative Organismal Biology, 5(1). https://doi.org/10.1093/iob/obad020
Results

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Parameters

Parameters for this dataset have not yet been identified


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Instruments

Dataset-specific Instrument Name
Leica SP8 X Confocal Laser Scanning microscope
Generic Instrument Name
Confocal Laser Scanning Microscope
Generic Instrument Description
A laser scanning confocal microscope is a type of confocal microscope that obtains high-resolution optical images with depth selectivity, in which a laser beam passes through a light source aperture and then is focused by an objective lens into a small (ideally diffraction-limited) focal volume within or on the surface of a specimen. The confocal microscope uses fluorescence optics. 'Confocal' means that the image is obtained from the focal plane only, any noise resulting from sample thickness being removed optically. 'Laser scanning' means the images are acquired point by point under localized laser excitation rather than full sample illumination, as in conventional widefield microscopy.


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Deployments

SKQ201915S

Website
Platform
R/V Sikuliaq
Report
Start Date
2019-06-29
End Date
2019-07-18
Description
Northern Gulf of Alaska Long-Term Ecological Research (NGA-LTER) See more cruise details on R2R https://www.rvdata.us/search/cruise/SKQ201915S 

TXF19

Website
Platform
R/V Tiglax
Report
Start Date
2019-09-11
End Date
2019-09-26
Description
Northern Gulf of Alaska Long-Term Ecological Research (NGA-LTER) Fall cruise


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Project Information

Collaborative Research: Molecular profiling of the ecophysiology of dormancy induction in calanid copepods of the Northern Gulf of Alaska LTER site (Diapause preparation)

Coverage: Northern Gulf of Alaska LTER


NSF Award Abstract:
The sub-arctic Pacific sustains major fisheries with nearly all commercially important species depending either directly or indirectly on lipid-rich copepods (Neocalanus flemingeri, Neocalanus plumchrus, Neocalanus cristatus and Calanus marshallae). In turn, these species depend on a short-lived spring algal bloom for growth and the accumulation of lipid stores in order to complete an annual life cycle that includes a period of dormancy. The intellectual thrust of this project measures how the timing and magnitude of algal blooms affect preparation for dormancy using a combination of field and experimental observations. The Northern Gulf of Alaska - with four calanid species that experience dormancy, steep environmental gradients, well-described phytoplankton bloom dynamics, and a concurrent NSF-LTER program - provides an unusual opportunity to identify the factors that affect dormancy preparation. Education and outreach plans are integrated with the research. Educational efforts focus on interdisciplinary opportunities for undergraduate, graduate and post-doctoral trainees. The project will generate content for existing graduate and undergraduate courses. U. of Alaska Fairbanks and U. Hawaii at Manoa are Alaska Native and Native Hawaiian Serving Institutions, and students from these groups will be recruited to participate in the project. Because fishing is a major industry in the Gulf of Alaska, outreach will communicate the role copepods play in marine ecosystems using the concept of a dynamic food web tied to production cycles.

Diapause (dormancy) and the accompanying accumulation of lipids in copepods have been identified as key drivers in high latitude ecosystems that support economically important fisheries, including those of the Gulf of Alaska. While the disappearance of lipid-rich copepods has been linked to severe declines in fish stocks, little is known about the environmental conditions that are required for the successful completion of the copepod's life cycle. A physiological profiling approach that measures relative gene expression will be used to test two alternative hypotheses: the lipid accumulation window hypothesis, which holds that individuals enter diapause only after they have accumulated sufficient lipid stores, and the developmental program hypothesis, which holds that once the diapause program is activated, progression occurs independent of lipid accumulation. The specific objectives are: 1) determine the effect of food levels during N. flemingeri copepodite stages on progression towards diapause using multiple physiological and developmental markers; 2) characterize the seasonal changes in the physiological profile of N. flemingeri across environmental gradients and across years; 3) compare physiological profiles across co-occurring calanid species (N. flemingeri, Neocalanus plumchrus, Neocalanus cristatus and Calanus marshallae); and 4) estimate the reproductive potential of the overwintering populations of N. flemingeri. The broader scientific significance includes the acquisition of new genomic data and molecular resources that will be made publicly available through established data repositories, and the development of new tools for routinely obtaining physiological profiles of copepods.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

 

NOTE: Petra Lenz is a former Principal Investigator (PI) and Andrew Christie is a former Co-Principal Investigator (Co-PI) on this project (award #1756767). Daniel Hartline is the PI listed for the award #1756767 and is now a former Co-PI on this project.



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Funding

Funding SourceAward
NSF Division of Ocean Sciences (NSF OCE)
NSF Division of Ocean Sciences (NSF OCE)
NSF Division of Ocean Sciences (NSF OCE)

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