Search

Search Results

• 61. [Article] The Evolutionary Stability of Partial Migration

  Citation × Citation Citation Abstract Copy Title: The Evolutionary Stability of Partial Migration Author: Ohms, Haley Title: The Evolutionary Stability of Partial Migration Author: Ohms, Haley Close

• 62. [Article] Dasatinib Modulates Invasive and Migratory Properties of Canine Osteosarcoma and has Therapeutic Potential in Affected Dogs

  © 2015 The Authors. Published by Elsevier Inc. on behalf of Neoplasia Press, Inc. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). The published ...

  Citation × Citation Citation Abstract Copy Title: Dasatinib Modulates Invasive and Migratory Properties of Canine Osteosarcoma and has Therapeutic Potential in Affected Dogs Author: Gullaba, Justine, Gelberg, Howard B., Marley, Kevin, Helfand, Stuart C., Seguin, Bernard © 2015 The Authors. Published by Elsevier Inc. on behalf of Neoplasia Press, Inc. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). The published article can be found at: http://www.transonc.com/ Title: Dasatinib Modulates Invasive and Migratory Properties of Canine Osteosarcoma and has Therapeutic Potential in Affected Dogs Author: Gullaba, Justine, Gelberg, Howard B., Marley, Kevin, Helfand, Stuart C., Seguin, Bernard © 2015 The Authors. Published by Elsevier Inc. on behalf of Neoplasia Press, Inc. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). The published article can be found at: http://www.transonc.com/ Close

• 63. [Article] Survey of Pathogens in Hatchery Chinook Salmon with Different Out-Migration Histories through the Snake and Columbia Rivers

  The operation of the Federal Columbia River Power System (FCRPS) has negatively affected threatened and endangered salmonid populations in the Pacific Northwest. Barging Snake River spring Chinook salmon ...

  Citation × Citation Citation Abstract Copy Title: Survey of Pathogens in Hatchery Chinook Salmon with Different Out-Migration Histories through the Snake and Columbia Rivers Author: Boylen, Deborah A., Collier, T.K., Dietrich, Joseph P., Arkoosh, Mary R., Strickland, Stacy A., Loge, F.J., Thompson, D.E., Van Gaest, Ahna L. The operation of the Federal Columbia River Power System (FCRPS) has negatively affected threatened and endangered salmonid populations in the Pacific Northwest. Barging Snake River spring Chinook salmon Oncorhynchus tshawytscha through the FCRPS is one effort to mitigate the effect of the hydrosystem on juvenile salmon out-migration. However, little is known about the occurrence and transmission of infectious agents in barged juvenile salmon relative to juvenile salmon that remain in-river to navigate to the ocean. We conducted a survey of hatchery-reared spring Chinook salmon at various points along their out-migration path as they left their natal hatcheries and either migrated in-river or were barged through the FCRPS. Salmon kidneys were screened by polymerase chain reaction for nine pathogens and one family of water molds. Eight pathogens were detected; the most prevalent were Renibacterium salmoninarum and infectious hematopoietic necrosis virus. Species in the family Saprolegniaceae were also commonly detected. Pathogen prevalence was significantly greater in fish that were barged through the FCRPS than in fish left to out-migrate in-river. These results suggest that the transmission of infectious agents to susceptible juvenile salmon occurs during the barging process. Therefore, management activities that reduce pathogen exposure during barging may increase the survival of juvenile Chinook salmon after they are released. Title: Survey of Pathogens in Hatchery Chinook Salmon with Different Out-Migration Histories through the Snake and Columbia Rivers Author: Boylen, Deborah A., Collier, T.K., Dietrich, Joseph P., Arkoosh, Mary R., Strickland, Stacy A., Loge, F.J., Thompson, D.E., Van Gaest, Ahna L. The operation of the Federal Columbia River Power System (FCRPS) has negatively affected threatened and endangered salmonid populations in the Pacific Northwest. Barging Snake River spring Chinook salmon Oncorhynchus tshawytscha through the FCRPS is one effort to mitigate the effect of the hydrosystem on juvenile salmon out-migration. However, little is known about the occurrence and transmission of infectious agents in barged juvenile salmon relative to juvenile salmon that remain in-river to navigate to the ocean. We conducted a survey of hatchery-reared spring Chinook salmon at various points along their out-migration path as they left their natal hatcheries and either migrated in-river or were barged through the FCRPS. Salmon kidneys were screened by polymerase chain reaction for nine pathogens and one family of water molds. Eight pathogens were detected; the most prevalent were Renibacterium salmoninarum and infectious hematopoietic necrosis virus. Species in the family Saprolegniaceae were also commonly detected. Pathogen prevalence was significantly greater in fish that were barged through the FCRPS than in fish left to out-migrate in-river. These results suggest that the transmission of infectious agents to susceptible juvenile salmon occurs during the barging process. Therefore, management activities that reduce pathogen exposure during barging may increase the survival of juvenile Chinook salmon after they are released. Close

• 64. [Article] Behavioral responses of Atlantic cod to sea temperature changes

  This is the publisher’s final pdf. The published article is copyrighted by the author(s) and published by John Wiley & Sons Ltd. The published article can be found at: http://onlinelibrary.wiley.com/jo...

  Citation × Citation Citation Abstract Copy Title: Behavioral responses of Atlantic cod to sea temperature changes Author: Freitas, Carla, Ciannelli, Lorenzo, Olsen, Esben Moland, Moland, Even, Knutsen, Halvor This is the publisher’s final pdf. The published article is copyrighted by the author(s) and published by John Wiley & Sons Ltd. The published article can be found at: http://onlinelibrary.wiley.com/journal/10.1002/%28ISSN%292045-7758 Title: Behavioral responses of Atlantic cod to sea temperature changes Author: Freitas, Carla, Ciannelli, Lorenzo, Olsen, Esben Moland, Moland, Even, Knutsen, Halvor This is the publisher’s final pdf. The published article is copyrighted by the author(s) and published by John Wiley & Sons Ltd. The published article can be found at: http://onlinelibrary.wiley.com/journal/10.1002/%28ISSN%292045-7758 Close

• 65. [Article] Study on the vertical distribution and movement of pink shrimp, Pandalus jordani, in the Pacific Ocean off Oregon.

  "Commercial Fisheries Research and Development Act: Progress Report" at head of title page. 12 p.

  Citation × Citation Citation Abstract Copy Title: Study on the vertical distribution and movement of pink shrimp, Pandalus jordani, in the Pacific Ocean off Oregon. Author: Robinson, Jack G., Milburn, Gary "Commercial Fisheries Research and Development Act: Progress Report" at head of title page. 12 p. Title: Study on the vertical distribution and movement of pink shrimp, Pandalus jordani, in the Pacific Ocean off Oregon. Author: Robinson, Jack G., Milburn, Gary "Commercial Fisheries Research and Development Act: Progress Report" at head of title page. 12 p. Close

• 66. [Article] Habitat use, movements, and behavior of postbreeding female canvasbacks in Manitoba

  The habitat use, movements, and behavioral energetics of unsuccessfully breeding female canvasbacks (Aythya valisineria) were examined during the preflightless period in southern Manitoba during 1989-90. ...

  Citation × Citation Citation Abstract Copy Title: Habitat use, movements, and behavior of postbreeding female canvasbacks in Manitoba Author: Devries, James H. The habitat use, movements, and behavioral energetics of unsuccessfully breeding female canvasbacks (Aythya valisineria) were examined during the preflightless period in southern Manitoba during 1989-90. Following breeding attempts, unsuccessful females generally expanded their home range on the breeding area, remained there for up to one month, preferentially used large semipermanent and permanent wetlands, and were gregarious. Nocturnal shifts in habitat use were apparent and may be an adaptation to avoid predation by mink. Unsuccessful females depart the breeding area to participate in a moult migration of up to 300 km independent of the departure of males. Wetlands approximately 40 km north of the breeding area appear to serve as staging wetlands for the moult migration. Both Swan Lake and Dauphin Lake in central Manitoba appear to be important moulting waters for unsuccessful females. Time spent on the breeding area and on staging wetlands may be required to replenish fat reserves for the moult migration, the moult itself, and upcoming fall migration. During the preflightless period, females spend approximately 40% of their diurnal energy budget feeding and their daily energy expenditure is approximately 1200-1300 kJ. The cost of the moult migration from the breeding area to Swan Lake is estimated to be between 1700 and 3100 kJ requiring between 40 and 80 g of stored body fat. This study underscores the importance of breeding, staging and moulting habitats to female canvasback populations in Manitoba. Title: Habitat use, movements, and behavior of postbreeding female canvasbacks in Manitoba Author: Devries, James H. The habitat use, movements, and behavioral energetics of unsuccessfully breeding female canvasbacks (Aythya valisineria) were examined during the preflightless period in southern Manitoba during 1989-90. Following breeding attempts, unsuccessful females generally expanded their home range on the breeding area, remained there for up to one month, preferentially used large semipermanent and permanent wetlands, and were gregarious. Nocturnal shifts in habitat use were apparent and may be an adaptation to avoid predation by mink. Unsuccessful females depart the breeding area to participate in a moult migration of up to 300 km independent of the departure of males. Wetlands approximately 40 km north of the breeding area appear to serve as staging wetlands for the moult migration. Both Swan Lake and Dauphin Lake in central Manitoba appear to be important moulting waters for unsuccessful females. Time spent on the breeding area and on staging wetlands may be required to replenish fat reserves for the moult migration, the moult itself, and upcoming fall migration. During the preflightless period, females spend approximately 40% of their diurnal energy budget feeding and their daily energy expenditure is approximately 1200-1300 kJ. The cost of the moult migration from the breeding area to Swan Lake is estimated to be between 1700 and 3100 kJ requiring between 40 and 80 g of stored body fat. This study underscores the importance of breeding, staging and moulting habitats to female canvasback populations in Manitoba. Close

• 67. [Article] Critically endangered western gray whales migrate to the eastern North Pacific

  This is an author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by The Author(s) and published by the Royal Society. It can be found at: http://r...

  Citation × Citation Citation Abstract Copy Title: Critically endangered western gray whales migrate to the eastern North Pacific Author: Bradford, Amanda L., Tsidulko, Grigory A., Irvine, Ladd M., Mate, Bruce R., Rozhnov, Vyacheslav V., Vertyankin, Vladimir V., Ilyashenko, Valentin Yu. This is an author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by The Author(s) and published by the Royal Society. It can be found at: http://rsbl.royalsocietypublishing.org/ Title: Critically endangered western gray whales migrate to the eastern North Pacific Author: Bradford, Amanda L., Tsidulko, Grigory A., Irvine, Ladd M., Mate, Bruce R., Rozhnov, Vyacheslav V., Vertyankin, Vladimir V., Ilyashenko, Valentin Yu. This is an author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by The Author(s) and published by the Royal Society. It can be found at: http://rsbl.royalsocietypublishing.org/ Close

• 68. [Article] Seasonal movement, residency, and migration patterns of Wilson's Snipe (Gallinago delicata) across the annual cycle in the Willamette Valley of Oregon.

  Studies of avian movement ecology afford essential insights regarding species' life histories, population dynamics, habitat and resource requirements, and other ecological relationships. While it is widely ...

  Citation × Citation Citation Abstract Copy Title: Seasonal movement, residency, and migration patterns of Wilson's Snipe (Gallinago delicata) across the annual cycle in the Willamette Valley of Oregon. Author: Cline, Brittany B. Studies of avian movement ecology afford essential insights regarding species' life histories, population dynamics, habitat and resource requirements, and other ecological relationships. While it is widely recognized that events in different stages of the annual cycle have important implications for processes in avian ecology, evolution, and conservation, challenges associated with quantifying migratory connectivity frequently constrain annual-cycle approaches to the study of avian movement. The majority of cross-seasonal movement studies have been conducted to either (1) establish linkages between geographically distinct wintering, breeding and migratory stopover locations; or (2) assess site fidelity and movement within fractions of the annual cycle (i.e. individual seasons). Far fewer studies employ annual-cycle approaches to investigate how local and regional movement patterns of individuals change seasonally within an area of breeding and wintering-range overlap. Within western Oregon’s Willamette Valley in 2007, I quantified the intra- and inter-seasonal movement patterns, fidelity (regional/local), and migratory strategies of 37 radio-marked Wilson’s Snipe (Gallinago delicata) to elucidate residency status in a region of breeding and wintering-range overlap. Available evidence indicated the potential for a variety of possible migratory behaviors for this relatively understudied migratory species; results revealed that the group monitored constituted winter residents (74%), winter transients (14%), summer residents (9%), and one year-round resident breeder (3%). Findings indicated a lack of connectivity between populations captured during winter and summer, scant evidence of partial migration (one year-round resident), as well as the first documentation of between-season fidelity of snipe to the region (return of winter resident in subsequent fall). Spring migration chronology of radio-marked winter residents indicated a strong sex differential in timing of migration, with males departing an average of 9.68 days earlier than females (20.11 days including winter transients). In contrast, fall migration patterns were suggestive of inverse chronology (females departing before males). Male-biased winter sex ratios were consistent with observed latitudinal clines for other nonbreeding shorebird populations. The protracted spring migration periods resulted in gradual dispersal consistent with energy minimization migration strategies. Across seasons, the extent of movements and use of multiple wetland sites suggested that snipe were capable of exploratory movements, but more regularly perceived local and fine-scale segments of the landscape as connected. There were no differences in the areal extent of individual home-ranges, number of sites visited, individual mobility, or distances detected from capture sites by individual sex (or interaction of sex × season). However, movements differed significantly by season and residency, with individuals exhibiting contracted movements during late winter, and most expansive movements during precipitation-limited periods (late spring, summer, fall 2007). Mean home-range size was 3.52 ± 0.93 km2 (100% MCP) and 1.57 ± 0.42 km2 (95% fixed kernel), and did not vary by sex; however, home-range varied markedly by season (range 100% MCP = 1.04 – 7.56 km2). Overall results indicated variable fidelity patterns (e.g., prolonged periods of within-season residency, transient behavior, between-season fidelity, partial migration), which were indicative of a complex regional population structure. Wilson’s Snipe demonstrated striking differences in movement patterns, vagility and local site fidelity across seasons in the Willamette Valley, while previous studies of shorebird movement and habitat use in the region focused solely on winter and precipitation-copious periods. Furthermore, by highlighting the seasonal changes in snipe movement metrics, this study provides the first cross-seasonal profile of a shorebird species’ space-use in a region of breeding and wintering-range overlap. Results provide insight on the regional and local fidelity and movement patterns of shorebirds in a spatiotemporally dynamic wetland landscape, across multiple seasons. Furthermore, findings indicate that single-season approaches to wetland management in the region present the risk of mischaracterizing species’ spatial requirements, and highlight the need to consider: (1) cross-seasonal effects, and (2) inter-specific differences in shorebird life histories when developing regional wetland conservation plans. Title: Seasonal movement, residency, and migration patterns of Wilson's Snipe (Gallinago delicata) across the annual cycle in the Willamette Valley of Oregon. Author: Cline, Brittany B. Studies of avian movement ecology afford essential insights regarding species' life histories, population dynamics, habitat and resource requirements, and other ecological relationships. While it is widely recognized that events in different stages of the annual cycle have important implications for processes in avian ecology, evolution, and conservation, challenges associated with quantifying migratory connectivity frequently constrain annual-cycle approaches to the study of avian movement. The majority of cross-seasonal movement studies have been conducted to either (1) establish linkages between geographically distinct wintering, breeding and migratory stopover locations; or (2) assess site fidelity and movement within fractions of the annual cycle (i.e. individual seasons). Far fewer studies employ annual-cycle approaches to investigate how local and regional movement patterns of individuals change seasonally within an area of breeding and wintering-range overlap. Within western Oregon’s Willamette Valley in 2007, I quantified the intra- and inter-seasonal movement patterns, fidelity (regional/local), and migratory strategies of 37 radio-marked Wilson’s Snipe (Gallinago delicata) to elucidate residency status in a region of breeding and wintering-range overlap. Available evidence indicated the potential for a variety of possible migratory behaviors for this relatively understudied migratory species; results revealed that the group monitored constituted winter residents (74%), winter transients (14%), summer residents (9%), and one year-round resident breeder (3%). Findings indicated a lack of connectivity between populations captured during winter and summer, scant evidence of partial migration (one year-round resident), as well as the first documentation of between-season fidelity of snipe to the region (return of winter resident in subsequent fall). Spring migration chronology of radio-marked winter residents indicated a strong sex differential in timing of migration, with males departing an average of 9.68 days earlier than females (20.11 days including winter transients). In contrast, fall migration patterns were suggestive of inverse chronology (females departing before males). Male-biased winter sex ratios were consistent with observed latitudinal clines for other nonbreeding shorebird populations. The protracted spring migration periods resulted in gradual dispersal consistent with energy minimization migration strategies. Across seasons, the extent of movements and use of multiple wetland sites suggested that snipe were capable of exploratory movements, but more regularly perceived local and fine-scale segments of the landscape as connected. There were no differences in the areal extent of individual home-ranges, number of sites visited, individual mobility, or distances detected from capture sites by individual sex (or interaction of sex × season). However, movements differed significantly by season and residency, with individuals exhibiting contracted movements during late winter, and most expansive movements during precipitation-limited periods (late spring, summer, fall 2007). Mean home-range size was 3.52 ± 0.93 km2 (100% MCP) and 1.57 ± 0.42 km2 (95% fixed kernel), and did not vary by sex; however, home-range varied markedly by season (range 100% MCP = 1.04 – 7.56 km2). Overall results indicated variable fidelity patterns (e.g., prolonged periods of within-season residency, transient behavior, between-season fidelity, partial migration), which were indicative of a complex regional population structure. Wilson’s Snipe demonstrated striking differences in movement patterns, vagility and local site fidelity across seasons in the Willamette Valley, while previous studies of shorebird movement and habitat use in the region focused solely on winter and precipitation-copious periods. Furthermore, by highlighting the seasonal changes in snipe movement metrics, this study provides the first cross-seasonal profile of a shorebird species’ space-use in a region of breeding and wintering-range overlap. Results provide insight on the regional and local fidelity and movement patterns of shorebirds in a spatiotemporally dynamic wetland landscape, across multiple seasons. Furthermore, findings indicate that single-season approaches to wetland management in the region present the risk of mischaracterizing species’ spatial requirements, and highlight the need to consider: (1) cross-seasonal effects, and (2) inter-specific differences in shorebird life histories when developing regional wetland conservation plans. Close

• 69. [Article] Migratory behavior and passage of redband trout (Oncorhynchus mykiss) in the Donner und Blitzen River, Oregon

  Salmonids in arid high-elevation streams find themselves at the fringe of their tolerance range. Under the conditions they endure in such environments, long-distance migratory movements among widely dispersed ...

  Citation × Citation Citation Abstract Copy Title: Migratory behavior and passage of redband trout (Oncorhynchus mykiss) in the Donner und Blitzen River, Oregon Author: Anderson, Matthew C. Salmonids in arid high-elevation streams find themselves at the fringe of their tolerance range. Under the conditions they endure in such environments, long-distance migratory movements among widely dispersed habitats may be an important mechanism for some fish to persist, and even thrive. The Donner und Blitzen (Blitzen) River redband trout (Oncorhynchus mykiss gairdneri) population is known to have a migratory life-history component, but little is known about the timing, spatial patterns, or ecological context of the migration. I tracked trout movements and passage delays at diversion dams with radio telemetry and passive integrated transponder (PIT) tags from March 2007 to November 2008. PIT tag readers established at four locations (river km 1, 35, 48, and 76) recorded large-scale movements of trout. Three of the readers also recorded ladder entry time, ladder ascending time, and total passage time of each trout. My results indicated the existence of a life-history in which redband trout made long-distance migrations both as sub-adults and as adults. While adult trout migrated for reproductive purposes, movement of immature individuals appeared to be a response to seasonal stream temperature conditions. Trout migration rate was positively correlated with fork length and mean river discharge but was not associated with stream temperature, tagging method, or the number of dams passed. The upstream-most detection location for radio-tagged adults that reached potential spawning habitat was not different for trout from the lower river versus the middle river (t(42) = 1.07, p = .29); however, lower river trout reached spawning habitats an average of 20 days later (t(42) = 3.78, p < .001). Passage times at the dams were not affected by discharge, fork length, or tagging method. At a jump-pool ladder trout were 7.23 times more likely to pass during day than at night (2(1, N = 40) = 9.96, p = .002). At a Denil ladder, trout were 25.6% more likely to pass with each degree Celsius increase in stream temperature (2(1, N = 22) = 4.39, p = .036). At all three dams, a greater proportion of the total passage time involved trout finding and entering the ladder than ascending the ladder after initial entry. Trout passage times varied significantly between each of the dams. This study highlights the importance of landscape-scale distribution of habitats and refugia in determining life-history and movement patterns of trout. Migratory behavior was related to both life-stage and environmental conditions. Maintaining connectivity with efficient passage throughout the river is a critical element in managing migratory fish populations like the one in this study. The well-functioning fish ladders were those that provided adequate fish attraction, while those ladders with poor attraction delayed migrating trout for long periods. Title: Migratory behavior and passage of redband trout (Oncorhynchus mykiss) in the Donner und Blitzen River, Oregon Author: Anderson, Matthew C. Salmonids in arid high-elevation streams find themselves at the fringe of their tolerance range. Under the conditions they endure in such environments, long-distance migratory movements among widely dispersed habitats may be an important mechanism for some fish to persist, and even thrive. The Donner und Blitzen (Blitzen) River redband trout (Oncorhynchus mykiss gairdneri) population is known to have a migratory life-history component, but little is known about the timing, spatial patterns, or ecological context of the migration. I tracked trout movements and passage delays at diversion dams with radio telemetry and passive integrated transponder (PIT) tags from March 2007 to November 2008. PIT tag readers established at four locations (river km 1, 35, 48, and 76) recorded large-scale movements of trout. Three of the readers also recorded ladder entry time, ladder ascending time, and total passage time of each trout. My results indicated the existence of a life-history in which redband trout made long-distance migrations both as sub-adults and as adults. While adult trout migrated for reproductive purposes, movement of immature individuals appeared to be a response to seasonal stream temperature conditions. Trout migration rate was positively correlated with fork length and mean river discharge but was not associated with stream temperature, tagging method, or the number of dams passed. The upstream-most detection location for radio-tagged adults that reached potential spawning habitat was not different for trout from the lower river versus the middle river (t(42) = 1.07, p = .29); however, lower river trout reached spawning habitats an average of 20 days later (t(42) = 3.78, p < .001). Passage times at the dams were not affected by discharge, fork length, or tagging method. At a jump-pool ladder trout were 7.23 times more likely to pass during day than at night (2(1, N = 40) = 9.96, p = .002). At a Denil ladder, trout were 25.6% more likely to pass with each degree Celsius increase in stream temperature (2(1, N = 22) = 4.39, p = .036). At all three dams, a greater proportion of the total passage time involved trout finding and entering the ladder than ascending the ladder after initial entry. Trout passage times varied significantly between each of the dams. This study highlights the importance of landscape-scale distribution of habitats and refugia in determining life-history and movement patterns of trout. Migratory behavior was related to both life-stage and environmental conditions. Maintaining connectivity with efficient passage throughout the river is a critical element in managing migratory fish populations like the one in this study. The well-functioning fish ladders were those that provided adequate fish attraction, while those ladders with poor attraction delayed migrating trout for long periods. Close

• 70. [Article] Degradation of Extracellular Matrix Proteins by Bovine Embryonic Urokinase-Type Plasminogen Activator

  The bovine blastocyst is composed of a one-celled layer of trophectoderm surrounding a fluid filled sac called the blastocoel and a ball of cells called the inner cell mass (ICM). On Day 8 (Day 0=fertilization) ...

  Citation × Citation Citation Abstract Copy Title: Degradation of Extracellular Matrix Proteins by Bovine Embryonic Urokinase-Type Plasminogen Activator Author: Hansen, Lance The bovine blastocyst is composed of a one-celled layer of trophectoderm surrounding a fluid filled sac called the blastocoel and a ball of cells called the inner cell mass (ICM). On Day 8 (Day 0=fertilization) in bovine embryos, endodermal cells leave the ICM, migrate over the extracellular matrix (ECM) on the blastocoelic side of the trophectoderm and form a full layer of extraembryonic endoderm on Day 10. Three ECM glycoproteins have been shown to be involved in endodermal cell migration: fibronectin, vitronectin, and laminin. Bovine endodermal cells migrate on fibronectin and vitronectin whereas laminin is believed to be produced when migration is complete to stabilize cell- ECM interactions (Haun and Menino, 2001; Singleton and Menino, 2005). Urokinase-type plasminogen activator (uPA) activity has been detected in bovine endodermal cells during cell migration, but its exact role is not understood (Haun and Menino, 2001). The matrix metalloproteinase (MMP) inhibitor, TIMP-2, is stimulatory to bovine endodermal cell proliferation and migration, and enhances PA production but MMP have not been detected in bovine ICM (Haun and Menino, 2001). Endodermal cell migration may require limited proteolysis of the ECM, and if this is the case uPA may be the protease involved. The objective of this research was to determine if the bovine embryonic uPA can directly degrade fibronectin and laminin without plasminogen activation. Embryos for this project were obtained from cows at the OSU Beef Cattle Center and donations by breeders. Conditioned medium was collected from embryos ranging from morulae (Day 6) to hatched blastocysts (Day 12). Conditioned medium was assayed for embryonic uPA (ePA) activity using a caseinolytic agar gel assay. Proteolysis of the ECM glycoproteins by ePA was determined by SDS-polyacrylamide gel electrophoresis. No autolysis was observed over 48 hr of incubation at 39º C for fibronectin, collagen ІV, or laminin using SDS-PAGE. Lysis was observed for laminin by human urokinase, but no fibronectin breakdown occured with human urokinase. Laminin showed no degradation by bovine ePA, however the polypeptide profile of fibronectin demonstrated cleavage by bovine ePA. These results indicate that ePA can proteolytically degrade fibronectin in the absence of plasminogen. Cleavage of fibronectin may aide in endodermal cell proliferation by facilitating movement over the ECM. Title: Degradation of Extracellular Matrix Proteins by Bovine Embryonic Urokinase-Type Plasminogen Activator Author: Hansen, Lance The bovine blastocyst is composed of a one-celled layer of trophectoderm surrounding a fluid filled sac called the blastocoel and a ball of cells called the inner cell mass (ICM). On Day 8 (Day 0=fertilization) in bovine embryos, endodermal cells leave the ICM, migrate over the extracellular matrix (ECM) on the blastocoelic side of the trophectoderm and form a full layer of extraembryonic endoderm on Day 10. Three ECM glycoproteins have been shown to be involved in endodermal cell migration: fibronectin, vitronectin, and laminin. Bovine endodermal cells migrate on fibronectin and vitronectin whereas laminin is believed to be produced when migration is complete to stabilize cell- ECM interactions (Haun and Menino, 2001; Singleton and Menino, 2005). Urokinase-type plasminogen activator (uPA) activity has been detected in bovine endodermal cells during cell migration, but its exact role is not understood (Haun and Menino, 2001). The matrix metalloproteinase (MMP) inhibitor, TIMP-2, is stimulatory to bovine endodermal cell proliferation and migration, and enhances PA production but MMP have not been detected in bovine ICM (Haun and Menino, 2001). Endodermal cell migration may require limited proteolysis of the ECM, and if this is the case uPA may be the protease involved. The objective of this research was to determine if the bovine embryonic uPA can directly degrade fibronectin and laminin without plasminogen activation. Embryos for this project were obtained from cows at the OSU Beef Cattle Center and donations by breeders. Conditioned medium was collected from embryos ranging from morulae (Day 6) to hatched blastocysts (Day 12). Conditioned medium was assayed for embryonic uPA (ePA) activity using a caseinolytic agar gel assay. Proteolysis of the ECM glycoproteins by ePA was determined by SDS-polyacrylamide gel electrophoresis. No autolysis was observed over 48 hr of incubation at 39º C for fibronectin, collagen ІV, or laminin using SDS-PAGE. Lysis was observed for laminin by human urokinase, but no fibronectin breakdown occured with human urokinase. Laminin showed no degradation by bovine ePA, however the polypeptide profile of fibronectin demonstrated cleavage by bovine ePA. These results indicate that ePA can proteolytically degrade fibronectin in the absence of plasminogen. Cleavage of fibronectin may aide in endodermal cell proliferation by facilitating movement over the ECM. Close