Development and early differentiation of gonad in the European eel (Anguilla anguilla [L.], Anguilliformes, Teleostei): A cytological and ultrastructural study
The structure of the gonad of the European eel (Anguilla anguilla [L.]), an "undifferentiated" gonochoristic teleost, was investigated by transmission electron microscopy from 6-8 cm elvers to 22 cm yellow eels with juvenile hermaphroditic gonads. The pear-shaped gonads of 6-8 cm elvers as...
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ftunivferrarair:oai:sfera.unife.it:11392/1203684 2024-04-14T08:01:01+00:00 Development and early differentiation of gonad in the European eel (Anguilla anguilla [L.], Anguilliformes, Teleostei): A cytological and ultrastructural study GRANDI, Gilberto COLOMBO, Giuseppe Grandi, Gilberto Colombo, Giuseppe 1997 STAMPA http://hdl.handle.net/11392/1203684 eng eng info:eu-repo/semantics/altIdentifier/wos/WOS:A1997WA97200008 volume:231 issue:2 firstpage:195 lastpage:216 journal:JOURNAL OF MORPHOLOGY http://hdl.handle.net/11392/1203684 10.1002/(SICI)1097-4687(199702)231:2<195::AID-JMOR8>3.0.CO;2-D info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-0031025643 info:eu-repo/semantics/article 1997 ftunivferrarair 2024-03-21T17:39:27Z The structure of the gonad of the European eel (Anguilla anguilla [L.]), an "undifferentiated" gonochoristic teleost, was investigated by transmission electron microscopy from 6-8 cm elvers to 22 cm yellow eels with juvenile hermaphroditic gonads. The pear-shaped gonads of 6-8 cm elvers assume, in 12-15 cm eels, a lamellar shape and enlarge by migration of germ cells, which we refer to as primary primordial germ cells. In the gonads of -16 cm eels, the primary primordial germ cells multiply, giving rise to clusters of germ cells that have ultrastructural characteristics of the primary primordial germ cells but show giant mitochondria, enlarged Golgi complexes, and round bodies not limited by membranes We refer to these as secondary primordial germ cells. In 16-18 cm eels, syncytial clones of oogonia interconnected by cytoplasmic bridges are also observed. In 18-22-cm-Iong eels, the gonads contain primordial germ cells, oogonial clones, early oocyte cysts, single oocytes in early growth stages, and primary spermatogonia. Such germ cells are present in the same cross section where they are either intermingled or are in areas of predominantly female germ cells close to areas with predominantly male germ cells. These gonads are juvenile hermaphroditic and should be considered ambisexual because in larger eels they differentiate either into an ovary or into a testis. Somatic cells always envelop the germ cells following their migration into the gonad. These somatic cells first show similar ultra- structural features and then differentiate either into early Sertoli cells investing spermatogonia, or into early follicular (granulosa) cells investing the early previtellogenic oocytes. In eels -14 cm long, primitive steroid-producing cells also migrate into the gonad. In the ambisexual gonad they differentiate either into immature Leydig cells in the male areas, or into early special cells of the theca in the female areas. Nerve fibers are joined to the steroid-producing cells. Gonad development and differentiation are ... Article in Journal/Newspaper Anguilla anguilla Università degli Studi di Ferrara: CINECA IRIS |
institution |
Open Polar |
collection |
Università degli Studi di Ferrara: CINECA IRIS |
op_collection_id |
ftunivferrarair |
language |
English |
description |
The structure of the gonad of the European eel (Anguilla anguilla [L.]), an "undifferentiated" gonochoristic teleost, was investigated by transmission electron microscopy from 6-8 cm elvers to 22 cm yellow eels with juvenile hermaphroditic gonads. The pear-shaped gonads of 6-8 cm elvers assume, in 12-15 cm eels, a lamellar shape and enlarge by migration of germ cells, which we refer to as primary primordial germ cells. In the gonads of -16 cm eels, the primary primordial germ cells multiply, giving rise to clusters of germ cells that have ultrastructural characteristics of the primary primordial germ cells but show giant mitochondria, enlarged Golgi complexes, and round bodies not limited by membranes We refer to these as secondary primordial germ cells. In 16-18 cm eels, syncytial clones of oogonia interconnected by cytoplasmic bridges are also observed. In 18-22-cm-Iong eels, the gonads contain primordial germ cells, oogonial clones, early oocyte cysts, single oocytes in early growth stages, and primary spermatogonia. Such germ cells are present in the same cross section where they are either intermingled or are in areas of predominantly female germ cells close to areas with predominantly male germ cells. These gonads are juvenile hermaphroditic and should be considered ambisexual because in larger eels they differentiate either into an ovary or into a testis. Somatic cells always envelop the germ cells following their migration into the gonad. These somatic cells first show similar ultra- structural features and then differentiate either into early Sertoli cells investing spermatogonia, or into early follicular (granulosa) cells investing the early previtellogenic oocytes. In eels -14 cm long, primitive steroid-producing cells also migrate into the gonad. In the ambisexual gonad they differentiate either into immature Leydig cells in the male areas, or into early special cells of the theca in the female areas. Nerve fibers are joined to the steroid-producing cells. Gonad development and differentiation are ... |
author2 |
Grandi, Gilberto Colombo, Giuseppe |
format |
Article in Journal/Newspaper |
author |
GRANDI, Gilberto COLOMBO, Giuseppe |
spellingShingle |
GRANDI, Gilberto COLOMBO, Giuseppe Development and early differentiation of gonad in the European eel (Anguilla anguilla [L.], Anguilliformes, Teleostei): A cytological and ultrastructural study |
author_facet |
GRANDI, Gilberto COLOMBO, Giuseppe |
author_sort |
GRANDI, Gilberto |
title |
Development and early differentiation of gonad in the European eel (Anguilla anguilla [L.], Anguilliformes, Teleostei): A cytological and ultrastructural study |
title_short |
Development and early differentiation of gonad in the European eel (Anguilla anguilla [L.], Anguilliformes, Teleostei): A cytological and ultrastructural study |
title_full |
Development and early differentiation of gonad in the European eel (Anguilla anguilla [L.], Anguilliformes, Teleostei): A cytological and ultrastructural study |
title_fullStr |
Development and early differentiation of gonad in the European eel (Anguilla anguilla [L.], Anguilliformes, Teleostei): A cytological and ultrastructural study |
title_full_unstemmed |
Development and early differentiation of gonad in the European eel (Anguilla anguilla [L.], Anguilliformes, Teleostei): A cytological and ultrastructural study |
title_sort |
development and early differentiation of gonad in the european eel (anguilla anguilla [l.], anguilliformes, teleostei): a cytological and ultrastructural study |
publishDate |
1997 |
url |
http://hdl.handle.net/11392/1203684 |
genre |
Anguilla anguilla |
genre_facet |
Anguilla anguilla |
op_relation |
info:eu-repo/semantics/altIdentifier/wos/WOS:A1997WA97200008 volume:231 issue:2 firstpage:195 lastpage:216 journal:JOURNAL OF MORPHOLOGY http://hdl.handle.net/11392/1203684 10.1002/(SICI)1097-4687(199702)231:2<195::AID-JMOR8>3.0.CO;2-D info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-0031025643 |
_version_ |
1796306302384734208 |