Sex determination in the European eel ( Anguilla anguilla, L.)
Metaphase chromosomes from cultured blood cells of female, male, and hermaphroditic European eels were analyzed. In addition, both gonads from each of the specimens were examined microscopically to ensure correct sexing. The karyological investigation revealed that in some of the specimens a heterom...
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Language: | English |
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S. Karger AG
1983
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Online Access: | http://dx.doi.org/10.1159/000131981 https://www.karger.com/Article/Pdf/131981 |
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crskarger:10.1159/000131981 2024-06-16T07:33:26+00:00 Sex determination in the European eel ( Anguilla anguilla, L.) Wiberg, U.H. 1983 http://dx.doi.org/10.1159/000131981 https://www.karger.com/Article/Pdf/131981 en eng S. Karger AG https://www.karger.com/Services/SiteLicenses https://www.karger.com/Services/SiteLicenses Cytogenetic and Genome Research volume 36, issue 4, page 589-598 ISSN 1424-8581 1424-859X journal-article 1983 crskarger https://doi.org/10.1159/000131981 2024-05-22T13:00:26Z Metaphase chromosomes from cultured blood cells of female, male, and hermaphroditic European eels were analyzed. In addition, both gonads from each of the specimens were examined microscopically to ensure correct sexing. The karyological investigation revealed that in some of the specimens a heteromorphic chromosome pair was present. This heteromorphism appeared in both sexes and in the hermaphrodite. C-banding and silver nitrate staining demonstrated that the heteromorphism was due to quantitative differences in constitutive heterochromatin and nucleolar organizing regions in the short arm of chromosome 8. In G-banded preparations it was demonstrated that, except for the heteromorphism mentioned, the karyotypes from both sexes and the hermaphrodite were identical. With the G-band technique it was also easily demonstrated that both the largest metacentric (No. 1) and the smallest metacentric (No. 11) had homologs. Therefore, in contrast to some earlier reports which claimed that these two chromosomes were a heteromorphic pair of sex chromosomes, it is concluded that Anguilla anguilla has no heteromorphic sex chromosomes. The implication of these findings are discussed in relation to the many reports of strongly skewed sex ratios found in commercial eel farms. It is tentatively hypothesized that sex determination in A. anguilla may be metagamic and that sex inversion may occur in this species. Article in Journal/Newspaper Anguilla anguilla European eel Karger Cytogenetic and Genome Research 36 4 589 598 |
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Metaphase chromosomes from cultured blood cells of female, male, and hermaphroditic European eels were analyzed. In addition, both gonads from each of the specimens were examined microscopically to ensure correct sexing. The karyological investigation revealed that in some of the specimens a heteromorphic chromosome pair was present. This heteromorphism appeared in both sexes and in the hermaphrodite. C-banding and silver nitrate staining demonstrated that the heteromorphism was due to quantitative differences in constitutive heterochromatin and nucleolar organizing regions in the short arm of chromosome 8. In G-banded preparations it was demonstrated that, except for the heteromorphism mentioned, the karyotypes from both sexes and the hermaphrodite were identical. With the G-band technique it was also easily demonstrated that both the largest metacentric (No. 1) and the smallest metacentric (No. 11) had homologs. Therefore, in contrast to some earlier reports which claimed that these two chromosomes were a heteromorphic pair of sex chromosomes, it is concluded that Anguilla anguilla has no heteromorphic sex chromosomes. The implication of these findings are discussed in relation to the many reports of strongly skewed sex ratios found in commercial eel farms. It is tentatively hypothesized that sex determination in A. anguilla may be metagamic and that sex inversion may occur in this species. |
format |
Article in Journal/Newspaper |
author |
Wiberg, U.H. |
spellingShingle |
Wiberg, U.H. Sex determination in the European eel ( Anguilla anguilla, L.) |
author_facet |
Wiberg, U.H. |
author_sort |
Wiberg, U.H. |
title |
Sex determination in the European eel ( Anguilla anguilla, L.) |
title_short |
Sex determination in the European eel ( Anguilla anguilla, L.) |
title_full |
Sex determination in the European eel ( Anguilla anguilla, L.) |
title_fullStr |
Sex determination in the European eel ( Anguilla anguilla, L.) |
title_full_unstemmed |
Sex determination in the European eel ( Anguilla anguilla, L.) |
title_sort |
sex determination in the european eel ( anguilla anguilla, l.) |
publisher |
S. Karger AG |
publishDate |
1983 |
url |
http://dx.doi.org/10.1159/000131981 https://www.karger.com/Article/Pdf/131981 |
genre |
Anguilla anguilla European eel |
genre_facet |
Anguilla anguilla European eel |
op_source |
Cytogenetic and Genome Research volume 36, issue 4, page 589-598 ISSN 1424-8581 1424-859X |
op_rights |
https://www.karger.com/Services/SiteLicenses https://www.karger.com/Services/SiteLicenses |
op_doi |
https://doi.org/10.1159/000131981 |
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Cytogenetic and Genome Research |
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36 |
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4 |
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589 |
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598 |
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1802004443843002368 |