Ultrastructure des cellules germinales au cours du d�veloppement embryonnaire du L�zard vivipare (Lacerta vivipara Jacquin)

Hubert, Jean

doi:10.1007/bf00335230

Cited by 11 publications

(3 citation statements)

References 27 publications

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“…The structure and development of follicles in S. mitranus has been reconstructed as shown in the Figure . In general, the structure of the germinal beds and some cytoplasmic and nuclear features of oogonia and early oocytes in S. mitranus are similar to those described for other lizards (Arronet, ; Bou‐Resli, ; Filosa & Taddei, ; Hubert, , , ; Hubert, ; Hubert, ; Klosterman, ; Klosterman, ). However, in L. sicula , the presence of cytoplasmic bridges has been reported between the developing oogonia in the germinal bed (Filosa & Taddei, ).…”

Section: Discussionsupporting

confidence: 75%

“…Such bridges were not detected in S. mitranus or other species such as A. scutellatus (Bou‐Resli, ) and G. coeruleus (Klosterman, ). The paranucleolar mass is thought to be an important cytological marker of primordial germ cells and oogonia in lizards (Hubert, , , , , ), but was not detected in the oogonia of S. mitranus as in other lizards (Filosa & Taddei, ; Klosterman, ; Klosterman, ).…”

Section: Discussionmentioning

confidence: 99%

“…The ultrastructure of oogenesis of lizards has been described in few species, including Zootoca vivipara (Hubert, ), Lacerta sicula (Filosa & Taddei, ), Acanthodactylus scutellatus (Bou‐Resli, ), and Elgaria coerulea (Klosterman, ). Notably, relatively few species of squamates have been studied (Vieira et al, ), including the family Scincidae, the largest family of lizards.…”

Section: Introductionmentioning

confidence: 99%

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Ultrastructural and histochemical study of previtellogenic oogenesis in the desert lizard Scincus mitranus (Squamata, Sauropsida)

Alwasel

Harrath

2019

Journal of Morphology

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The structure of the granulosa in reptilian sauropsids varies between groups. We investigated the follicle development in the desert lizard Scincus mitranus. In the germinal bed, oogonia, and primary oocytes were identified and found to be interspersed between the epithelial cells. Previtellogenesis was divided into three stages: early, transitional, and late previtellogenic stages. During the early previtellogenic stage (diplotene), the oocyte is invested by small epithelia cells that formed a complete single layer, which may be considered as a young follicle. The transitional previtellogenic stage was marked by proliferation and differentiation of the granulosa layer from a homogenous layer consisting of only small cells to a heterogeneous layer containing three cell types: small, intermediate, and large cells. The late previtellogenic stage was marked by high‐synthetic activity of large cells and the initiation of cytoplasmic bridges between large granulosa cells and the oocyte. Small cells were the only type of granulosa cells that underwent division. Thus, these cells may be stem cells for the granulosa cell population and may develop into intermediate and subsequently large cells. The intermediate cells may be precursors of large cells, as suggested by their ultrastructure. The ultrastructure of the large granulosa was indicative of their high synthetic activity. Histochemical analysis indicated the presence of cholesterol and phospholipids in the cytoplasm of large cells, the zona pellucida, among the microvilli, in the bridges region, and in the cortical region of the oocyte cytoplasm. These materials may be transferred from large cells into the oocyte through cytoplasmic bridges and provide nutritive function to large cells rather than functioning in steroidogenesis or vitellogenesis.

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Section: Discussionsupporting

confidence: 75%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Ultrastructural and histochemical study of previtellogenic oogenesis in the desert lizard Scincus mitranus (Squamata, Sauropsida)

Alwasel

Harrath

2019

Journal of Morphology

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The ultrastructure of germinal beds in the ovary of Gerrhonotus coeruleus (Reptilia: Anguidae)

Klosterman

1983

Journal of Morphology

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A study of ovarian structure in adult Alligator Lizards (Gerrhonotus coeruleus) was conducted by light microscopy and transmission electron microscopy. Particular attention was directed to characterizing the ultrastructure of germ-line cells, prior to follicle formation. General ovarian structure in this lizard is similar to that of other lizards. The paired organs are hollow, thin-walled sacs containing follicles in roughly 3 to 4 size classes. Ovarian germinal tissue consists of oogonia (diploid cells which divide mitotically) and oocytes (meiotic cells), intermixed with ovarian surface epithelial cells. Germ cells reside in two dorsal patches of epithelium per ovary (germinal beds), as is common in lizards. Oogonia in interphase show a highly dispersed chromatin pattern. Within oogonia cytoplasm, Golgi complexes are scarce, rough endoplasmic reticulum is absent, and lipid droplets are rare. Ribosomes are scattered in small clusters. Small, round vesicles are common in all oogonia; glycogen-like granules are present in some. Mitochondria form a juxta-nuclear mass within which groups of several mitochondria surround a dense granule. 'Nuage' granules also are found unassociated with mitochondria. Oocytes are present in stages of meiotic prophase up to diplotene. Synaptinemal complexes are seen in several (pachytene) cells. The cytoplasm of oocytes differs from that of oogonia in that mitochondria do not form groups, and nuage and glycogen are absent, whereas small round vesicles and large irregular vesicles are common. The ultrastructural similarities in germ cells of a reptile as compared to those of other vertebrates strengthens the notion that germ-line cells possess (or lack) qualities related to the undifferentiated state of these cells.

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Ultrastructure of primordial germ cells in the early chick embryo

Ukeshima

Fujimoto

1984

Ultrastructure of Reproduction

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Ultrastructure des cellules germinales au cours du d�veloppement embryonnaire du L�zard vivipare (Lacerta vivipara Jacquin)

Cited by 11 publications

References 27 publications

Ultrastructural and histochemical study of previtellogenic oogenesis in the desert lizard Scincus mitranus (Squamata, Sauropsida)

Ultrastructural and histochemical study of previtellogenic oogenesis in the desert lizard Scincus mitranus (Squamata, Sauropsida)

The ultrastructure of germinal beds in the ovary of Gerrhonotus coeruleus (Reptilia: Anguidae)

Ultrastructure of primordial germ cells in the early chick embryo

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