Age and seasonal variation in testis and baculum morphology in East Greenland polar bears (Ursus maritimus ) in relation to high concentrations of persistent organic pollutants
Persistent organic pollutants (POPs) are found in high concentrations in the Artic. Polar bears (Ursus maritimus) are one of the most exposed mammals in the Arctic and are thereby vulnerable to reproductive disruption. The aim of this study was to investigate male polar bear reproduction based on a...
Published in: | Environmental Research |
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Main Authors: | , , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
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2019
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Online Access: | https://pure.au.dk/portal/en/publications/849c334a-0d44-43d9-ad78-04a37fa2342d https://doi.org/10.1016/j.envres.2019.03.036 http://www.scopus.com/inward/record.url?scp=85063467644&partnerID=8YFLogxK |
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ftuniaarhuspubl:oai:pure.atira.dk:publications/849c334a-0d44-43d9-ad78-04a37fa2342d 2024-02-04T09:58:33+01:00 Age and seasonal variation in testis and baculum morphology in East Greenland polar bears (Ursus maritimus ) in relation to high concentrations of persistent organic pollutants Spörndly-Nees, Ellinor Holm, Lena van Beest, Floris M. Fakhrzadeh, Azadeh Ekstedt, Elisabeth Letcher, Robert Magnusson, Ulf Desforges, Jean Pierre Dietz, Rune Sonne, Christian 2019-06 https://pure.au.dk/portal/en/publications/849c334a-0d44-43d9-ad78-04a37fa2342d https://doi.org/10.1016/j.envres.2019.03.036 http://www.scopus.com/inward/record.url?scp=85063467644&partnerID=8YFLogxK eng eng https://pure.au.dk/portal/en/publications/849c334a-0d44-43d9-ad78-04a37fa2342d info:eu-repo/semantics/closedAccess Spörndly-Nees , E , Holm , L , van Beest , F M , Fakhrzadeh , A , Ekstedt , E , Letcher , R , Magnusson , U , Desforges , J P , Dietz , R & Sonne , C 2019 , ' Age and seasonal variation in testis and baculum morphology in East Greenland polar bears (Ursus maritimus ) in relation to high concentrations of persistent organic pollutants ' , Environmental Research , vol. 173 , pp. 246-254 . https://doi.org/10.1016/j.envres.2019.03.036 Bioaccumulative toxicants Ecotoxicology Reproduction Spermatogenesis Top predators article 2019 ftuniaarhuspubl https://doi.org/10.1016/j.envres.2019.03.036 2024-01-11T00:00:41Z Persistent organic pollutants (POPs) are found in high concentrations in the Artic. Polar bears (Ursus maritimus) are one of the most exposed mammals in the Arctic and are thereby vulnerable to reproductive disruption. The aim of this study was to investigate male polar bear reproduction based on a detailed evaluation of testis histology and to assess possible effects of environmental chemicals on male polar bear reproduction. Reproductive groups that were identified based on histology were as follows: actively reproductive (REP), non-reproductive either with degenerated testes (DEG), undeveloped seminiferous tubules (UND), or morphology in-transition (INT). Categorization into these groups was supported by significant differences in testis and baculum measurements among REP, DEG, and UND, as well as differences in the area and diameter of seminiferous tubules among REP, DEG, and UND. These results show that it is possible to identify the reproductive stage in polar bears even if capture date and or age is lacking. Based on testis morphology we suggest that adult male polar bears from East Greenland have active spermatogenesis in February to June, and inactive degenerated testes in August to January. January to February was the main period of reproductive transition, characterised by a shift between inactive and active spermatogenesis. Baculum and testis size measurements decreased significantly with increasing concentrations of the chlordane metabolite oxychlordane, suggesting a potential impact on male reproductive success. Half of the investigated polar bears in REP group displayed signs of disorganization of the spermatogenesis which might be a sign of disrupted reproduction. However, no correlations with levels of the investigated POPs were detected. Reproductive organ measurements in polar bears differed significantly between REP and DEG groups, which cannot be explained by age, and therefore should be considered when investigating the effect of POPs on male reproduction. Article in Journal/Newspaper Arctic East Greenland Greenland Ursus maritimus Aarhus University: Research Arctic Greenland Environmental Research 173 246 254 |
institution |
Open Polar |
collection |
Aarhus University: Research |
op_collection_id |
ftuniaarhuspubl |
language |
English |
topic |
Bioaccumulative toxicants Ecotoxicology Reproduction Spermatogenesis Top predators |
spellingShingle |
Bioaccumulative toxicants Ecotoxicology Reproduction Spermatogenesis Top predators Spörndly-Nees, Ellinor Holm, Lena van Beest, Floris M. Fakhrzadeh, Azadeh Ekstedt, Elisabeth Letcher, Robert Magnusson, Ulf Desforges, Jean Pierre Dietz, Rune Sonne, Christian Age and seasonal variation in testis and baculum morphology in East Greenland polar bears (Ursus maritimus ) in relation to high concentrations of persistent organic pollutants |
topic_facet |
Bioaccumulative toxicants Ecotoxicology Reproduction Spermatogenesis Top predators |
description |
Persistent organic pollutants (POPs) are found in high concentrations in the Artic. Polar bears (Ursus maritimus) are one of the most exposed mammals in the Arctic and are thereby vulnerable to reproductive disruption. The aim of this study was to investigate male polar bear reproduction based on a detailed evaluation of testis histology and to assess possible effects of environmental chemicals on male polar bear reproduction. Reproductive groups that were identified based on histology were as follows: actively reproductive (REP), non-reproductive either with degenerated testes (DEG), undeveloped seminiferous tubules (UND), or morphology in-transition (INT). Categorization into these groups was supported by significant differences in testis and baculum measurements among REP, DEG, and UND, as well as differences in the area and diameter of seminiferous tubules among REP, DEG, and UND. These results show that it is possible to identify the reproductive stage in polar bears even if capture date and or age is lacking. Based on testis morphology we suggest that adult male polar bears from East Greenland have active spermatogenesis in February to June, and inactive degenerated testes in August to January. January to February was the main period of reproductive transition, characterised by a shift between inactive and active spermatogenesis. Baculum and testis size measurements decreased significantly with increasing concentrations of the chlordane metabolite oxychlordane, suggesting a potential impact on male reproductive success. Half of the investigated polar bears in REP group displayed signs of disorganization of the spermatogenesis which might be a sign of disrupted reproduction. However, no correlations with levels of the investigated POPs were detected. Reproductive organ measurements in polar bears differed significantly between REP and DEG groups, which cannot be explained by age, and therefore should be considered when investigating the effect of POPs on male reproduction. |
format |
Article in Journal/Newspaper |
author |
Spörndly-Nees, Ellinor Holm, Lena van Beest, Floris M. Fakhrzadeh, Azadeh Ekstedt, Elisabeth Letcher, Robert Magnusson, Ulf Desforges, Jean Pierre Dietz, Rune Sonne, Christian |
author_facet |
Spörndly-Nees, Ellinor Holm, Lena van Beest, Floris M. Fakhrzadeh, Azadeh Ekstedt, Elisabeth Letcher, Robert Magnusson, Ulf Desforges, Jean Pierre Dietz, Rune Sonne, Christian |
author_sort |
Spörndly-Nees, Ellinor |
title |
Age and seasonal variation in testis and baculum morphology in East Greenland polar bears (Ursus maritimus ) in relation to high concentrations of persistent organic pollutants |
title_short |
Age and seasonal variation in testis and baculum morphology in East Greenland polar bears (Ursus maritimus ) in relation to high concentrations of persistent organic pollutants |
title_full |
Age and seasonal variation in testis and baculum morphology in East Greenland polar bears (Ursus maritimus ) in relation to high concentrations of persistent organic pollutants |
title_fullStr |
Age and seasonal variation in testis and baculum morphology in East Greenland polar bears (Ursus maritimus ) in relation to high concentrations of persistent organic pollutants |
title_full_unstemmed |
Age and seasonal variation in testis and baculum morphology in East Greenland polar bears (Ursus maritimus ) in relation to high concentrations of persistent organic pollutants |
title_sort |
age and seasonal variation in testis and baculum morphology in east greenland polar bears (ursus maritimus ) in relation to high concentrations of persistent organic pollutants |
publishDate |
2019 |
url |
https://pure.au.dk/portal/en/publications/849c334a-0d44-43d9-ad78-04a37fa2342d https://doi.org/10.1016/j.envres.2019.03.036 http://www.scopus.com/inward/record.url?scp=85063467644&partnerID=8YFLogxK |
geographic |
Arctic Greenland |
geographic_facet |
Arctic Greenland |
genre |
Arctic East Greenland Greenland Ursus maritimus |
genre_facet |
Arctic East Greenland Greenland Ursus maritimus |
op_source |
Spörndly-Nees , E , Holm , L , van Beest , F M , Fakhrzadeh , A , Ekstedt , E , Letcher , R , Magnusson , U , Desforges , J P , Dietz , R & Sonne , C 2019 , ' Age and seasonal variation in testis and baculum morphology in East Greenland polar bears (Ursus maritimus ) in relation to high concentrations of persistent organic pollutants ' , Environmental Research , vol. 173 , pp. 246-254 . https://doi.org/10.1016/j.envres.2019.03.036 |
op_relation |
https://pure.au.dk/portal/en/publications/849c334a-0d44-43d9-ad78-04a37fa2342d |
op_rights |
info:eu-repo/semantics/closedAccess |
op_doi |
https://doi.org/10.1016/j.envres.2019.03.036 |
container_title |
Environmental Research |
container_volume |
173 |
container_start_page |
246 |
op_container_end_page |
254 |
_version_ |
1789963007717015552 |