Swimming suppresses hepatic vitellogenesis in European female silver eels as shown by expression of the estrogen receptor 1, vitellogenin1 and vitellogenin2 in the liver
Abstract Background When European silver eels (Anguilla anguilla) venture into the Atlantic Ocean for their 6,000 km semelparous spawning run to the Sargasso Sea, they are still in a prepubertal stage. Further sexual development appears to be blocked by dopaminergic inhibition of hypothalamus and pi...
Published in: | Reproductive Biology and Endocrinology |
---|---|
Main Authors: | , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
BMC
2010
|
Subjects: | |
Online Access: | https://doi.org/10.1186/1477-7827-8-27 https://doaj.org/article/10bff36eca2841b997005d1c6a144bf3 |
id |
ftdoajarticles:oai:doaj.org/article:10bff36eca2841b997005d1c6a144bf3 |
---|---|
record_format |
openpolar |
spelling |
ftdoajarticles:oai:doaj.org/article:10bff36eca2841b997005d1c6a144bf3 2023-05-15T13:28:12+02:00 Swimming suppresses hepatic vitellogenesis in European female silver eels as shown by expression of the estrogen receptor 1, vitellogenin1 and vitellogenin2 in the liver Nieveen Maaike C Schnabel Denhi Palstra Arjan P Spaink Herman P van den Thillart Guido 2010-03-01T00:00:00Z https://doi.org/10.1186/1477-7827-8-27 https://doaj.org/article/10bff36eca2841b997005d1c6a144bf3 EN eng BMC http://www.rbej.com/content/8/1/27 https://doaj.org/toc/1477-7827 doi:10.1186/1477-7827-8-27 1477-7827 https://doaj.org/article/10bff36eca2841b997005d1c6a144bf3 Reproductive Biology and Endocrinology, Vol 8, Iss 1, p 27 (2010) Gynecology and obstetrics RG1-991 Reproduction QH471-489 article 2010 ftdoajarticles https://doi.org/10.1186/1477-7827-8-27 2023-01-08T01:28:23Z Abstract Background When European silver eels (Anguilla anguilla) venture into the Atlantic Ocean for their 6,000 km semelparous spawning run to the Sargasso Sea, they are still in a prepubertal stage. Further sexual development appears to be blocked by dopaminergic inhibition of hypothalamus and pituitary activity. Recently, we found that swimming for several weeks in freshwater stimulated the incorporation of fat droplets in the oocytes. So, it was hypothesized that long term swimming in seawater would release the inhibition further and would also stimulate the production of vitellogenin by the liver. Methods For this study a swim-flume was constructed to allow simulated migration of migratory female silver eels for 3 months (1,420 km) in natural seawater at 20 degrees C. Primers were designed for polymerase chain reactions to measure the mRNA expression of estrogen receptor 1 (esr1), vitellogenin1 (vtg1) and vitellogenin2 (vtg2) genes in the liver of European female silver eels. Results In comparison to resting eels, swimming eels showed a diminished expression of esr1, vtg1 and vtg2 in the liver. They also had lower plasma calcium (Ca; indicative of vitellogenin) levels in their blood. This showed that vitellogenesis is more strongly suppressed in swimming than in resting eels. However, when eels were subsequently stimulated by 3 weekly carp pituitary extract injections, the expression of the same genes and plasma levels of Ca strongly increased in both groups to similar levels, thus equalizing the initial differences between resting and swimming. Conclusions It is concluded that vitellogenesis remains suppressed during resting and even more during swimming. The fact that swimming stimulates fat deposition in the oocytes but suppresses vitellogenesis indicates that these events are separated in nature and occur sequentially. Swimming-suppressed vitellogenesis may imply that in nature eels undergo vitellogenesis and final maturation near or at the spawning grounds. Article in Journal/Newspaper Anguilla anguilla Directory of Open Access Journals: DOAJ Articles Reproductive Biology and Endocrinology 8 1 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Gynecology and obstetrics RG1-991 Reproduction QH471-489 |
spellingShingle |
Gynecology and obstetrics RG1-991 Reproduction QH471-489 Nieveen Maaike C Schnabel Denhi Palstra Arjan P Spaink Herman P van den Thillart Guido Swimming suppresses hepatic vitellogenesis in European female silver eels as shown by expression of the estrogen receptor 1, vitellogenin1 and vitellogenin2 in the liver |
topic_facet |
Gynecology and obstetrics RG1-991 Reproduction QH471-489 |
description |
Abstract Background When European silver eels (Anguilla anguilla) venture into the Atlantic Ocean for their 6,000 km semelparous spawning run to the Sargasso Sea, they are still in a prepubertal stage. Further sexual development appears to be blocked by dopaminergic inhibition of hypothalamus and pituitary activity. Recently, we found that swimming for several weeks in freshwater stimulated the incorporation of fat droplets in the oocytes. So, it was hypothesized that long term swimming in seawater would release the inhibition further and would also stimulate the production of vitellogenin by the liver. Methods For this study a swim-flume was constructed to allow simulated migration of migratory female silver eels for 3 months (1,420 km) in natural seawater at 20 degrees C. Primers were designed for polymerase chain reactions to measure the mRNA expression of estrogen receptor 1 (esr1), vitellogenin1 (vtg1) and vitellogenin2 (vtg2) genes in the liver of European female silver eels. Results In comparison to resting eels, swimming eels showed a diminished expression of esr1, vtg1 and vtg2 in the liver. They also had lower plasma calcium (Ca; indicative of vitellogenin) levels in their blood. This showed that vitellogenesis is more strongly suppressed in swimming than in resting eels. However, when eels were subsequently stimulated by 3 weekly carp pituitary extract injections, the expression of the same genes and plasma levels of Ca strongly increased in both groups to similar levels, thus equalizing the initial differences between resting and swimming. Conclusions It is concluded that vitellogenesis remains suppressed during resting and even more during swimming. The fact that swimming stimulates fat deposition in the oocytes but suppresses vitellogenesis indicates that these events are separated in nature and occur sequentially. Swimming-suppressed vitellogenesis may imply that in nature eels undergo vitellogenesis and final maturation near or at the spawning grounds. |
format |
Article in Journal/Newspaper |
author |
Nieveen Maaike C Schnabel Denhi Palstra Arjan P Spaink Herman P van den Thillart Guido |
author_facet |
Nieveen Maaike C Schnabel Denhi Palstra Arjan P Spaink Herman P van den Thillart Guido |
author_sort |
Nieveen Maaike C |
title |
Swimming suppresses hepatic vitellogenesis in European female silver eels as shown by expression of the estrogen receptor 1, vitellogenin1 and vitellogenin2 in the liver |
title_short |
Swimming suppresses hepatic vitellogenesis in European female silver eels as shown by expression of the estrogen receptor 1, vitellogenin1 and vitellogenin2 in the liver |
title_full |
Swimming suppresses hepatic vitellogenesis in European female silver eels as shown by expression of the estrogen receptor 1, vitellogenin1 and vitellogenin2 in the liver |
title_fullStr |
Swimming suppresses hepatic vitellogenesis in European female silver eels as shown by expression of the estrogen receptor 1, vitellogenin1 and vitellogenin2 in the liver |
title_full_unstemmed |
Swimming suppresses hepatic vitellogenesis in European female silver eels as shown by expression of the estrogen receptor 1, vitellogenin1 and vitellogenin2 in the liver |
title_sort |
swimming suppresses hepatic vitellogenesis in european female silver eels as shown by expression of the estrogen receptor 1, vitellogenin1 and vitellogenin2 in the liver |
publisher |
BMC |
publishDate |
2010 |
url |
https://doi.org/10.1186/1477-7827-8-27 https://doaj.org/article/10bff36eca2841b997005d1c6a144bf3 |
genre |
Anguilla anguilla |
genre_facet |
Anguilla anguilla |
op_source |
Reproductive Biology and Endocrinology, Vol 8, Iss 1, p 27 (2010) |
op_relation |
http://www.rbej.com/content/8/1/27 https://doaj.org/toc/1477-7827 doi:10.1186/1477-7827-8-27 1477-7827 https://doaj.org/article/10bff36eca2841b997005d1c6a144bf3 |
op_doi |
https://doi.org/10.1186/1477-7827-8-27 |
container_title |
Reproductive Biology and Endocrinology |
container_volume |
8 |
container_issue |
1 |
_version_ |
1766402756961107968 |