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Full-Text Articles in Life Sciences

Acth Challenge: Stress Response Across Tadpole Development, Lauren W. Mobo, Lucas Jimenez, Lisa L. Surber-Cunningham, Eva K. Fischer Apr 2023

Acth Challenge: Stress Response Across Tadpole Development, Lauren W. Mobo, Lucas Jimenez, Lisa L. Surber-Cunningham, Eva K. Fischer

PRECS student projects

Research Questions

  1. Do tadpoles excrete more cortisol or corticosterone?
  2. Do tadpoles excrete more corticosterone after ACTH injections?
  3. Does the ACTH stress response change across development?


Effects Of Early‑Life Experience On Innovation And Problem‑Solving In Captive Coyotes, Andrew C. Garcia, Mitchell A. Parsons, Julie K. Young Sep 2022

Effects Of Early‑Life Experience On Innovation And Problem‑Solving In Captive Coyotes, Andrew C. Garcia, Mitchell A. Parsons, Julie K. Young

USDA Wildlife Services: Staff Publications

Early-life experience often shapes behaviors like innovation and exploration. These behaviors are important to animals encountering novel food resources in diverse habitats, such as mesocarnivores in urban areas. To understand if early-life experiences impact later-life behavior, we examined how coyotes (Canis latrans) responded to a multi-access puzzle box at two life stages: pup (~ 7 weeks) and dispersal (~ 10 months). We first exposed pups, still living with their parents and littermates, to a baited puzzle box. At dispersal age, we again tested both these pups and an age-matched control group that was not exposed to the puzzle …


Comparative Study Of Leachate Characterization: Implication For Sustainable Environmental Management, Osakpolor Marvellous Omorogieva, Victory Itua Igberase Jul 2021

Comparative Study Of Leachate Characterization: Implication For Sustainable Environmental Management, Osakpolor Marvellous Omorogieva, Victory Itua Igberase

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

Understanding the sources of environmental stressors, the role of geology, climate and technology would provide a guide to solving the problems posed by such stressor. The study examine the sources of wastes in Ikhueniro open dumpsite located in Benin city, Nigeria and characterize the leachate emanating from it. This will assist in adequate design of managerial scheme to tackle the menace posed by it while putting into consideration the role of geology, climate and technology. The key objectives are to carry out field study, characterize wastes in the dumpsite and collect raw leachate emanating from the wastes heap in order …


Polyzonus Fasciatus (Fabricius, 1781) (Coleoptera: Cerambycidae) - Ein Artporträt, Volker Neumann, Davaa Lkhagvasuren Jan 2016

Polyzonus Fasciatus (Fabricius, 1781) (Coleoptera: Cerambycidae) - Ein Artporträt, Volker Neumann, Davaa Lkhagvasuren

Erforschung biologischer Ressourcen der Mongolei / Exploration into the Biological Resources of Mongolia, ISSN 0440-1298

This paper focuses on the distribution of Polyzonus fasciatus (Coleoptera, Cerambycidae) in Mongolia and describes biological aspects of its development.


Beyond Climate-Smart Agriculture: Toward Safe Operating Spaces For Global Food Systems, Henry Neufeldt, Molly Jahn, Bruce M. Campbell, John R. Beddington, Fabrice Declerck, Alessandro De Pinto, Jay Gulledge, Jonathan Hellin, Mario Herrero, Andy Jarvis, David Lezaks, Holger Meinke, Todd Rosenstock, Mary Scholes, Robert Scholes, Sonja Vermeulen, Eva Wollenberg, Robert Zougmoré Aug 2013

Beyond Climate-Smart Agriculture: Toward Safe Operating Spaces For Global Food Systems, Henry Neufeldt, Molly Jahn, Bruce M. Campbell, John R. Beddington, Fabrice Declerck, Alessandro De Pinto, Jay Gulledge, Jonathan Hellin, Mario Herrero, Andy Jarvis, David Lezaks, Holger Meinke, Todd Rosenstock, Mary Scholes, Robert Scholes, Sonja Vermeulen, Eva Wollenberg, Robert Zougmoré

Rubenstein School of Environment and Natural Resources Faculty Publications

Agriculture is considered to be "climate-smart" when it contributes to increasing food security, adaptation and mitigation in a sustainable way. This new concept now dominates current discussions in agricultural development because of its capacity to unite the agendas of the agriculture, development and climate change communities under one brand. In this opinion piece authored by scientists from a variety of international agricultural and climate research communities, we argue that the concept needs to be evaluated critically because the relationship between the three dimensions is poorly understood, such that practically any improved agricultural practice can be considered climate-smart. This lack of …


Synthesizing Larval Competence Dynamics And Reef-Scale Retention Reveals A High Potential For Self-Recruitment In Corals, Joana Figueiredo, Andrew H. Baird, Sean R. Connolly Mar 2013

Synthesizing Larval Competence Dynamics And Reef-Scale Retention Reveals A High Potential For Self-Recruitment In Corals, Joana Figueiredo, Andrew H. Baird, Sean R. Connolly

Marine & Environmental Sciences Faculty Articles

Many organisms have a complex life-cycle in which dispersal occurs at the propagule stage. For marine environments, there is growing evidence that high levels of recruitment back to the natal population (self-recruitment) are common in many marine organisms. For fish, swimming behavior is frequently invoked as a key mechanism allowing high self-recruitment. For organisms with weak-swimming larvae, such as many marine invertebrates, the mechanisms behind self-recruitment are less clear. Here, we assessed whether the combination of passive retention of larvae due to re-circulation processes near reefs, and the dynamics of settlement competence, can produce the high levels of self-recruitment previously …


Bryophyte Species Composition Over Moisture Gradients In The Windmill Islands, East Antarctica: Development Of A Baseline For Monitoring Climate Change Impacts, J Wasley, S A. Robinson, J D. Turnbull, D H. King, W Wanek, M Popp Oct 2012

Bryophyte Species Composition Over Moisture Gradients In The Windmill Islands, East Antarctica: Development Of A Baseline For Monitoring Climate Change Impacts, J Wasley, S A. Robinson, J D. Turnbull, D H. King, W Wanek, M Popp

Faculty of Science - Papers (Archive)

Extreme environmental conditions prevail on the Antarctic continent and limit plant diversity to cryptogamic communities, dominated by bryophytes and lichens. Even small abiotic shifts, associated with climate change, are likely to have pronounced impacts on these communities that currently exist at their physiological limit of survival. Changes to moisture availability, due to precipitation shifts or alterations to permanent snow reserves, will most likely cause greatest impact. In order to establish a baseline for determining the effect of climate change on continental Antarctic terrestrial communities and to better understand bryophyte species distributions in relation to moisture in a floristically important Antarctic …


Development Of A Spatial Data Infrastructure For Coastal Management In The Amirante Islands, Seychelles, Sarah M. Hamylton, Justin Prosper Jan 2012

Development Of A Spatial Data Infrastructure For Coastal Management In The Amirante Islands, Seychelles, Sarah M. Hamylton, Justin Prosper

Faculty of Science - Papers (Archive)

Spatial data infrastructures play a key role in coastal management decision making in the Seychelles. This paper describes four components of a web-based spatial data infrastructure that were developed to facilitate coastal management of the Amirante Islands in the Seychelles. The four components include: (i) the institutional arrangement for using spatial data effectively to address local management challenges, (ii) the production of island habitat maps from remotely sensed data, (iii) the tasks undertaken for promoting access to and use of this spatial data, and (iv) an example of how this data is used for a specific coastal management application in …


Slides: Chapter 7 Of The Commission Report, David L. Bernhardt Jun 2010

Slides: Chapter 7 Of The Commission Report, David L. Bernhardt

The Past, Present, and Future of Our Public Lands: Celebrating the 40th Anniversary of the Public Land Law Review Commission’s Report, One Third of the Nation’s Land (Martz Summer Conference, June 2-4)

Presenter: David L. Bernhardt, Partner, Brownstein Hyatt Farber Schreck (Washington, DC) and former Solicitor for U.S. Department of the Interior

14 slides


Estuarine Blue Infrastructure: Priority Conservation Areas For The Seaside Of Virginia’S Eastern Shore, Center For Coastal Resources Management, Virginia Institute Of Marine Science May 2010

Estuarine Blue Infrastructure: Priority Conservation Areas For The Seaside Of Virginia’S Eastern Shore, Center For Coastal Resources Management, Virginia Institute Of Marine Science

Reports

This project is an extension of earlier efforts within the coastal zone of Virginia to build a platform for enhanced Blue and Green Infrastructure planning. This project is motivated by an interest in extending statewide conservation efforts into estuarine systems and recognition that land use decisions on the upland effect water quality and habitat health in the receiving waters. The project in its entirety has been accomplished in distinct parts. Part one develops a Cumulative Resource Assessment to evaluate the distribution of aquatic natural resources within waters of Virginia’s Chesapeake Bay waters, Back Bay of Virginia Beach, Virginia, and the …


Development Of A Regional Habitat Classification Scheme For The Amirante Islands, Seychelles, Sarah Hamylton, Tom Spencer, Annelise Hagan Jan 2010

Development Of A Regional Habitat Classification Scheme For The Amirante Islands, Seychelles, Sarah Hamylton, Tom Spencer, Annelise Hagan

Faculty of Science - Papers (Archive)

A collaborative expedition between Khaled bin Sultan Living Oceans Foundation, Cambridge Coastal Research Unit and Seychelles Centre for Marine Research and Technology – Marine Parks Authority (SCMRT-MPA) was conducted to the southern Seychelles, western Indian Ocean, in January 2005. This resulted in a series of habitat maps of the reefs and reef islands of the Amirantes Archipelago, derived from remotely-sensed Compact Airborne Spectrographic Imager (CASI) data. The procedures used in map development, image processing techniques and field survey methods are outlined. Habitat classification, and regional-scale comparisons of relative habitat composition are described. The study demonstrates the use of remote sensing …


Impact Of Ocean Warming And Ocean Acidification On Larval Development And Calcification In The Sea Urchin Tripneustes Gratilla, Hannah Sheppard Brennand, Natalie Soars, Symon A. Dworjanyn, Andrew R. Davis, Maria Byrne Jan 2010

Impact Of Ocean Warming And Ocean Acidification On Larval Development And Calcification In The Sea Urchin Tripneustes Gratilla, Hannah Sheppard Brennand, Natalie Soars, Symon A. Dworjanyn, Andrew R. Davis, Maria Byrne

Faculty of Science - Papers (Archive)

Background: As the oceans simultaneously warm, acidify and increase in P-CO2, prospects for marine biota are of concern. Calcifying species may find it difficult to produce their skeleton because ocean acidification decreases calcium carbonate saturation and accompanying hypercapnia suppresses metabolism. However, this may be buffered by enhanced growth and metabolism due to warming.Methodology/Principal Findings: We examined the interactive effects of near-future ocean warming and increased acidification/P-CO2 on larval development in the tropical sea urchin Tripneustes gratilla. Larvae were reared in multifactorial experiments in flow-through conditions in all combinations of three temperature and three pH/P-CO2 treatments. Experiments were placed in the …


Slides: Agricultural Resilience And Urban Growth: A Closer Look, William R. Travis Jun 2009

Slides: Agricultural Resilience And Urban Growth: A Closer Look, William R. Travis

Western Water Law, Policy and Management: Ripples, Currents, and New Channels for Inquiry (Martz Summer Conference, June 3-5)

Presenter: William R. Travis, Department of Geography, Center for Science & Technology Policy Research, CIRES, University of Colorado at Boulder

30 slides


Slides: Integrated Policy, Planning, And Management Of Water Resources, Robert Wilkinson Jun 2009

Slides: Integrated Policy, Planning, And Management Of Water Resources, Robert Wilkinson

Western Water Law, Policy and Management: Ripples, Currents, and New Channels for Inquiry (Martz Summer Conference, June 3-5)

Presenter: Robert Wilkinson, Ph.D., Director of the Water Policy Program, Donald Bren School of Environmental Science and Management, University of California-- Santa Barbara

60 slides


Development And Application Of A System For The Analysis Of Atmospheric, Water And Sediment Nitrogen And Carbon, Ann Stavert, Stephen R. Wilson, Dianne F. Jolley Jan 2009

Development And Application Of A System For The Analysis Of Atmospheric, Water And Sediment Nitrogen And Carbon, Ann Stavert, Stephen R. Wilson, Dianne F. Jolley

Faculty of Science - Papers (Archive)

Eutrophication and climate change, key environmental concerns, are both linked to the carbon and nitrogen cycles hence the improved understanding of these cycles is essential. Currently, there is no system that simultaneously measures the fluxes of the three key gas phase products of nitrogen and carbon cycling (CO2, CH4 and N2O) in submerged ecosystems with hourly time resolution. A “Lake-in-a-box” (mesocosm) was developed in the laboratory which allowed the monitoring of key components of the carbon and nitrogen cycles within the air, water and sediments. The approach is automated, simple and time efficient and novel in its ability to examine …


Development Of Non-Antibiotic-Resistant, Chromosomally Based, Constitutive And Inducible Expression Systems For Aroa-Attenuated Salmonella Enterica Serovar Typhimurium, Jake Matic, Tamsin D. Terry, David Van Bockel, Tracy A. Maddocks, David Tinworth, Michael Jennings, Steven P Djordjevic, Mark J. Walker Jan 2009

Development Of Non-Antibiotic-Resistant, Chromosomally Based, Constitutive And Inducible Expression Systems For Aroa-Attenuated Salmonella Enterica Serovar Typhimurium, Jake Matic, Tamsin D. Terry, David Van Bockel, Tracy A. Maddocks, David Tinworth, Michael Jennings, Steven P Djordjevic, Mark J. Walker

Faculty of Science - Papers (Archive)

Live-vaccine delivery systems expressing two model antigens from Mycoplasma hyopneumoniae, F2(P97) (Adh) and NrdF, were constructed using Salmonella enterica serovar Typhimurium aroA (STM-1), and immunogenicity in mice was evaluated. Recombinant plasmid-based expression (PBE) and chromosomally based expression (CBE) systems were constructed. The PBE system was formed by cloning both antigen genes into pJLA507 to create an operon downstream of temperature-inducible promoters. Constitutive CBE was achieved using a promoter-trapping technique whereby the promoterless operon was stably integrated into the chromosome of STM-1, and the expression of antigens was assessed. The chromosomal position of the operon was mapped in four clones. Inducible …


Regional Development And Local Government: Three Generations Of Federal Intervention, Andrew H. Kelly, Brian Dollery, Bligh Grant Jan 2009

Regional Development And Local Government: Three Generations Of Federal Intervention, Andrew H. Kelly, Brian Dollery, Bligh Grant

Faculty of Science - Papers (Archive)

Contemporary Australian local government faces several daunting problems, not least escalating financial un-sustainability and local infrastructure depletion. The main response of the various state and territory governments has taken the form of a series structural reform programs, with a strong emphasis on forced amalgamation. However, widespread dissatisfaction with the consequences of these compulsory consolidation programs has led to a search for alternative policy solutions based largely on shared services and various types of regional co-operation between local councils. This paper seeks to place proposed ‘regional’ solutions to contemporary problems in historical perspective by providing a comparative account of three distinct …


Functional Transition In The Floral Receptacle Of The Sacred Lotus (Nelumbo Nucifera): From Thermogenesis To Photosynthesis, R. E. Miller, J. R. Watling, Sharon A. Robinson Jan 2009

Functional Transition In The Floral Receptacle Of The Sacred Lotus (Nelumbo Nucifera): From Thermogenesis To Photosynthesis, R. E. Miller, J. R. Watling, Sharon A. Robinson

Faculty of Science - Papers (Archive)

The receptacle of the sacred lotus is the main source of heat during the thermogenic stage of floral development. Following anthesis, it enlarges, greens and becomes a fully functional photosynthetic organ. We investigated development of photosynthetic traits during this unusual functional transition. There were two distinct phases of pigment accumulation in receptacles. Lutein and photoprotective xanthophyll cycle pigments accumulated first with 64% and 95% of the maximum, respectively, present prior to anthesis. Lutein epoxide comprised 32% of total carotenoids in yellow receptacles, but declined with development. By contrast, more than 85% of maximum total chlorophyll, β-carotene and Rubisco were produced …


Word Sense Disambiguation In Biomedical Ontologies With Term Co-Occurrence Analysis And Document Clustering, Bill Andreopoulos, Dimitra Alexopoulou, Michael Schroeder Sep 2008

Word Sense Disambiguation In Biomedical Ontologies With Term Co-Occurrence Analysis And Document Clustering, Bill Andreopoulos, Dimitra Alexopoulou, Michael Schroeder

Faculty Publications, Computer Science

With more and more genomes being sequenced, a lot of effort is devoted to their annotation with terms from controlled vocabularies such as the GeneOntology. Manual annotation based on relevant literature is tedious, but automation of this process is difficult. One particularly challenging problem is word sense disambiguation. Terms such as |development| can refer to developmental biology or to the more general sense. Here, we present two approaches to address this problem by using term co-occurrences and document clustering. To evaluate our method we defined a corpus of 331 documents on development and developmental biology. Term co-occurrence analysis achieves an …


Slides: The Urbanizing West: Limits To Water, Limits To Growth, Lora A. Lucero Jun 2008

Slides: The Urbanizing West: Limits To Water, Limits To Growth, Lora A. Lucero

Shifting Baselines and New Meridians: Water, Resources, Landscapes, and the Transformation of the American West (Summer Conference, June 4-6)

Presenter: Lora A. Lucero, AICP, American Planning Association

18 slides


Approaches To Development Of A User-Friendly Community Based Arsenic/Iron Removal Unit In Bangladesh, Khondoker Mahabub Hassan, Farooque Ahmed, Faisal Ibney Hai, Saleh Faraj Magram Jan 2008

Approaches To Development Of A User-Friendly Community Based Arsenic/Iron Removal Unit In Bangladesh, Khondoker Mahabub Hassan, Farooque Ahmed, Faisal Ibney Hai, Saleh Faraj Magram

Faculty of Science - Papers (Archive)

The present stydy focuses on the strategies to modify the design of a community based Arsenic - Iron Removal Unit (AIRU) based on the field performance of the AIRU and the feedback from the users. The ultimate aim was to offer a user-friendly and sustainable system. Appropriate modifications in the design of the developed unit reduced the propensities of water head-loss and media clogging, thereby yielding sustained flow rate. Introduction of a simple cleaning procerdure (98% flow-recovery with three successive backwashing sequences) successfully reduced the frequency of requirement of labor-intensive replacement of the whole filter media. Raw water with arsenic …


Currents In Water Resources Law And Policy: How Is “Prior” Coping With New Stresses? [Outline], A. Dan Tarlock, David H. Getches Jun 2007

Currents In Water Resources Law And Policy: How Is “Prior” Coping With New Stresses? [Outline], A. Dan Tarlock, David H. Getches

The Future of Natural Resources Law and Policy (Summer Conference, June 6-8)

3 pages.

Includes bibliographical references

"A. Dan Tarlock, Distinguished Professor of Law and Director, Program in Environmental and Energy Law, Chicago-Kent College of Law"

"David H. Getches, Dean and Raphael J. Moses Professor of Natural Resources Law, University of Colorado Law School"


Saving Special Places: Trends And Challenges With Protecting Public Lands [Outline], Robert B. Keiter Jun 2007

Saving Special Places: Trends And Challenges With Protecting Public Lands [Outline], Robert B. Keiter

The Future of Natural Resources Law and Policy (Summer Conference, June 6-8)

7 pages.

Includes bibliographical references

"Robert B. Keiter, Wallace Stegner Professor of Law, University of Utah, S.J. Quinney College of Law"


Reef Development At High-Latitudes During Multiple Interglacial Cycles: New Evidence From Lord Howe Island, Southwestern Pacific, David Kennedy, Colin D. Woodroffe, J -X Zhao Jan 2007

Reef Development At High-Latitudes During Multiple Interglacial Cycles: New Evidence From Lord Howe Island, Southwestern Pacific, David Kennedy, Colin D. Woodroffe, J -X Zhao

Faculty of Science - Papers (Archive)

Reef development during past Interglacial periods, when sea level and sea surface temperatures were higher than today, provide unique insights into how reef systems may respond to projected human-induced global warming. Lord Howe Island currently represents the southernmost limit of reef development in the Pacific. Reef growth of Pleistocene age has been inferred to have occurred around the island, and this paper provides the fi rst detailed descriptions on the character of this development. Two phases of reef growth are identifi ed, which occurred as isolated fringing reefs along the edge of the basaltic hills of the island. Uranium-series dating …


Policy Tools For Smart Growth In New England, New England Environmental Finance Center Nov 2006

Policy Tools For Smart Growth In New England, New England Environmental Finance Center

Smart Growth

Across New England communities have been experiencing a rapid outward surge of development away from our community and downtown centers. Effects of sprawl include a loss of wildlife habitat, farm and timber lands; increased costs of community services and higher taxes; auto-dependency, longer commutes, and increased congestion; increases in air and water pollution; a sedentary lifestyle and increased obesity; and losses to one’s sense of place and social ties.

State-level responses to sprawl have surfaced throughout New England in recent years. This report describes 11 examples of these responses, representing all six New England states and a diversity of recent …


The Growing Together Guide: A Companion Resource To The New England Environmental Finance Center/Melissa Paly Film, New England Environmental Finance Center Sep 2006

The Growing Together Guide: A Companion Resource To The New England Environmental Finance Center/Melissa Paly Film, New England Environmental Finance Center

Smart Growth

What local leader or public official wants to be faced with an SOS the “same old story” of public discord and confrontation over growth and development in one’s community? That situation has become a problem for efforts to promote smart growth. Investments are needed in the walkable, compact, traditional‐streetscape and mixed use neighborhoods and developments that are more sustainable and healthy than sprawl, for both people and the landscape. Yet attempts at such change all too often end up mired in costly public controversy and stalemate.


Development Of Robust Guidelines And Assessment Procedures For Metal Contaminated Sediments, David Strom, Stuart L. Simpson, Dianne F. Jolley Jan 2006

Development Of Robust Guidelines And Assessment Procedures For Metal Contaminated Sediments, David Strom, Stuart L. Simpson, Dianne F. Jolley

Faculty of Science - Papers (Archive)

Assessment of contaminated sediments and development of remediation strategies is becoming an important priority for regulators and industries worldwide. Although sediment quality assessment frameworks exist, poor scientific procedures and a limited understanding of species sensitivity to common contaminants hinders most assessment programs. Globally, sediment quality guidelines (SQGs) for metals vary over several orders of magnitude and are not based on clear cause-effect relationships. Although equilibrium partitioning approaches to developing SQGs have been attempted, the cause-effect relationships are weak due to the many other modifying factors that influence metal bioavailability and toxicity. The inherent lack of defensible SQGs for metals currently …


Combined Effects Of Solar Radiation And Desiccation On The Mortality And Development Of Encapsulated Embryos Of Rocky Shore Gastropods, R. Przeslawski Jan 2005

Combined Effects Of Solar Radiation And Desiccation On The Mortality And Development Of Encapsulated Embryos Of Rocky Shore Gastropods, R. Przeslawski

Faculty of Science - Papers (Archive)

Intertidal encapsulated embryos may be synchronously exposed to many environmental stressors, but interactions between some of these factors remain poorly understood. Here, the effects of solar radiation and desiccation on embryonic mortality and developmental rates were assessed using laboratory and field experiments. Egg masses of 3 intertidal gastropod species were exposed for 72 h to combinations of spectral (full spectrum, UV-blocked, dark) and daily emersion treatments (control, 15, 30, 60 min). Siphonaria denticulata and Bembicium nanum embryos were expected to be tolerant to emersion and UVR as they are routinely deposited on exposed rock platforms. In contrast, Dolabrifera brazieri embryos …


Development Of Watershed Management In New South Wales, Australia: A Coastal Perspective, Pedro I. J Fidelman, Robert John Morrison, Ron J. West Jan 2005

Development Of Watershed Management In New South Wales, Australia: A Coastal Perspective, Pedro I. J Fidelman, Robert John Morrison, Ron J. West

Faculty of Science - Papers (Archive)

Watershed management has become a prominent approach to natural resource management (NRM) in Australia and elsewhere. In the Australian State ofNew South Wales (NSW), catchment management - the NSW watershed management initiative - has been in place both in coastal and non-coastal areas for nearly two decades. In coastal areas, it is suggested that catchment management could play an important role in coastal and marine issues (NSW Coastcare et aI., 2004; Zann, 1996), as the Australia's coastal and marine environments have, in general, been affected by watershed-based activities (see e.g., Zann, 1996). Such a role would, however, require institutional changes, …


The Development Of Signal Transduction Pathways During Epididymal Maturation Is Calcium Dependent, Heath W. Ecroyd, Kelly Asquith, Russell C. Jones, Robert J. Aitken Jan 2004

The Development Of Signal Transduction Pathways During Epididymal Maturation Is Calcium Dependent, Heath W. Ecroyd, Kelly Asquith, Russell C. Jones, Robert J. Aitken

Faculty of Science - Papers (Archive)

Capacitation has been correlated with the activation of a cAMP-PKA-dependent signaling pathway leading to protein tyrosine phosphorylation. The ability to exhibit this response to cAMP matures during epididymal maturation in concert with the ability of the sperrnatozoa to capacitate. In this study, we have addressed the mechanisms by which spermatozoa gain the potential to activate this signaling pathway during epididymal maturation. In a modified Tyrode's medium containing 1.7 mM calcium, caput spermatozoa had significantly higher [Ca2+](i) than caudal cells and could not tyrosine phosphorylate in response to cAMP. However, in calcium-depleted medium both caput and caudal cells could exhibit a …