Endocrine Activity of the Corpus Luteum and Placenta during Pregnancy inChalcides chalcides(Reptilia, Squamata)

Guarino, Fabio Maria; Paulesu, Luana; Cardone, A; Bellini, Luigi; Ghiara, Gianfranco; Angelini, F.

doi:10.1006/gcen.1998.7098

Cited by 42 publications

(28 citation statements)

References 22 publications

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“…giant and interstitial placentomal chorionic cells are binucleated, similar to those observed in the mammalian trophoblast, where these cells have diploid nuclei and play an important role in the production of lactogen and steroids (Hoffman and Wooding, 1993). In viviparous reptiles such as Chalcides chalcides (with Type III allantoplacenta), progesterone production was detected in the maternal component of the placentome, after corpus luteum degeneration in late pregnancy (Guarino et al, 1998). The role of uterine and chorionic cells in hormone production must be evaluated in viviparous lizards, and particularly in species with Type IV allantoplacentation because it has been observed that corpora lutea degenerate very early in gestation in this population of Mabuya (Gómez and Ramírez-Pinilla, 2004).…”

Section: Placentomementioning

confidence: 94%

Allantoplacental ultrastructure of an Andean population ofMabuya (Squamata, Scincidae)

2006

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Mabuya species are highly matrotrophic viviparous lizards with Type IV epitheliochorial allantoplacenta. The allantoplacenta of an Andean population of this genus, currently assigned to Mabuya sp., possesses specializations related to histotrophic nutrition at the embryonic hemisphere (placentome, paraplacentome, and chorionic areolas), while at the abembryonic hemisphere it has a mixed function: histotrophic transfer (absorptive plaques) and hemotrophic nutrition (gas exchange in respiratory segments). These placental specializations were studied using high-resolution light microscopy and transmission electron microscopy, and were compared with those found in other squamate reptiles and eutherian mammals. Cytological features of the placentome suggest that this is an important region for nutritional provision; the paraplacentome also shows characteristics for nutrient transfer, especially lipids. Chorionic areolas allow the absorption of glandular products, as well as uterine and chorionic cellular debris produced by lysis of some cells of both epithelia during areola formation. In the absorptive plaques both uterine and chorionic epithelia are firmly attached and their cellular apices exhibit electron-dense granules that could be related to autocrine and paracrine functions. The short interhemal distance found in the respiratory segments confirms their role in gas exchange. A common feature of all regional specializations in the Mabuya sp. allantoplacenta is the presence of lipids in the interacting chorionic and uterine epithelia, suggesting that lipids are transferred throughout the entire embryonic chamber; placental transfer of lipids may be the principal fetal energy and lipid source in this species. In spite of this feature, each one of the specialized areas of the allantoplacenta has different features suggesting particular functions in the transfer of nutrients (as ions, lipids, proteins, amino acids, sugar, water, and gases), and in the possible synthesis of hormones and proteins. The placental complexity observed in this species of Mabuya is greater than in any other reptile, and resembles that of eutherian mammals: Each one of these specializations of the placental membranes in Mabuya sp. is similar to those found among different eutherian mammals, indicating a very impressive evolutionary convergence at the histological and cytological levels between both clades. However, no eutherian mammal species simultaneously displays all of these specializations in the embryonic chamber as does Mabuya sp.

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Section: Placentomementioning

confidence: 94%

Allantoplacental ultrastructure of an Andean population ofMabuya (Squamata, Scincidae)

2006

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“…For these species, as in most other species of Reptilia, maturation and most of the growth of the preovulatory oocyte occurs during vitellogenesis, involving the formation of a telolecithal egg. In terms of species with a high degree of placentotrophy (type III placentas), Weekes (1934) describes the corpus luteum of Pseudomoia entrecasteauxii, and the corpus luteum of Chalcides chalcides also has been studied (Badir, 1968;Guarino et al, 1998). In this latter species, although the egg is very small (diameter 3 m, Blackburn and Callard, 1997), vitellogenesis is conserved (deduced from fig.…”

Section: Ple Agama Atra Anolis Carolinensis Calotes Versicolor Chmentioning

confidence: 96%

Ovarian histology of the placentotrophic Mabuya mabouya (Squamata, Scincidae)

Gómez

Ramírez‐Pinilla

2003

Journal of Morphology

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Ovarian structure and folliculogenesis of females at different reproductive stages are described for the viviparous placentotrophic lizard Mabuya mabouya. The small ovaries have a thin wall formed by the ovarian epithelium and a thin tunica albuginea. One to two germinal beds that contain numerous oogonia and developing primordial follicles are derived from the ovarian epithelium and are next to the ovarian hilum. The ovarian cortex contains follicles at different stages of development, corpora lutea, and atretic follicles. The yolk nucleus and Balbiani complex were not evident in the ooplasm of previtellogenic follicles. The follicular epithelium of these follicles is polymorphic, as in other species of Squamata, but the larger cells are spherical and monolayered rather than pyriform. The zona radiata of the preovulatory follicles is less developed than in lecithotrophic species. These features suggest a decrease in metabolic and absorptive processes during follicular growth. In preovulatory follicles (1.5-1.8 mm diameter), primordial yolk vacuoles and small cortical granules are deposited in the ooplasm instead of fatty yolk platelets, so that only one stage of vitellogenesis is observed. Polyovular atretic follicles occur in some females. Follicular atresia is minimal for preovulatory follicles, but is more frequent in follicles with polymorphic epithelia. In the corpus luteum, the luteal tissue is formed from granulosa cells and luteolysis occurs during the late gastrula -- late neurula embryonic stages. Thus, the maintenance of gestation from the pharyngula to preparturition stages seems to be related to secretion of extraluteal progesterone, possibly of placental origin. These observed ovarian features are related to the high degree of placental complexity of this species and show that the evolution of advanced placentotrophy in species of this lineage has been accompanied by concomitant changes in ovarian function.

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“…From the size of juvenile samples (~6.5 cm snout-vent), we presume that they were 1-year old. Sexual maturity is reached at 3-4 years, pregnancy lasts approximately 10 weeks and parturition takes place around late July-early August [Angelini and Ghiara, 1991;Guarino et al, 1998]. For the earliest stages of development we have adopted the developmental chart available for Lacerta vivipara [Dufaure and Hubert, 1961], whereas from midpregnancy onward, because of drastically reduced limb development of the viviparous skink, we have used our earlier field experience as a guide to ontogenetic level [see Angelini and Ghiara, 1991;Guarino et al, 1998].…”

Section: Methodsmentioning

confidence: 99%

“…Sexual maturity is reached at 3-4 years, pregnancy lasts approximately 10 weeks and parturition takes place around late July-early August [Angelini and Ghiara, 1991;Guarino et al, 1998]. For the earliest stages of development we have adopted the developmental chart available for Lacerta vivipara [Dufaure and Hubert, 1961], whereas from midpregnancy onward, because of drastically reduced limb development of the viviparous skink, we have used our earlier field experience as a guide to ontogenetic level [see Angelini and Ghiara, 1991;Guarino et al, 1998]. Thus the following stages of development were utilized: stage 1 (corresponding to the stage 7 of Dufaure and Hubert and approximately 1 week post-fertilization; 7 embryos); stage 2 (stage 15 of Dufaure and Hubert, approximately 2 weeks post-fertilization; 8 embryos); stage 3 (starting from this stage it was not possible to compare the development with the atlas; mid-pregnancy; 6 embryos); stage 4 (nearing parturition; 8 embryos).…”

Section: Methodsmentioning

confidence: 99%

Localization of FMRFamide-Like Immunoreactivity in the Brain of the Viviparous Skink <i>(Chalcides chalcides)</i>

D’Aniello¹,

Fiorentin²,

Pinelli³

et al. 2001

Brain Behav Evol

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Neuroanatomical distribution of FMRFamide-like immunoreactivity was investigated in the brain and olfactory system of the viviparous skink, Chalcides chalcides. In the adult brain FMRFamide immunoreactive (ir) perikarya were observed in the diagonal band of Broca, medial septal nucleus, accumbens nucleus, bed nucleus of the anterior commissure, periventricular hypothalamic nucleus, lateral forebrain bundle, and lateral preoptic, subcommissural, suprachiasmatic and lateral hypothalamic areas. This pattern was seen in both male and female brains. Though all major brain areas showed FMRFamide-ir innervation, the densest ir fiber network was observed in the hypothalamus. During development, ir elements were observed for the first time in embryos at mid-pregnancy. FMRFamide perikarya were located along the ventral surface of the vomeronasal nerve, in the olfactory peduncle mediobasally, as well as in the anterior olfactory nucleus and olfactory tubercle. Furthermore, some ir neurons were observed in the rhombencephalic reticular substance; however, the ir fiber network was poorly developed. Later in development FMRFamide-ir neurons appeared also in the bed nucleus of the anterior commissure as well as the rhombencephalic nucleus of solitary tract and the dorsal motor nucleus of vagus nerve. In juveniles, the distribution profile of FMRFamide immunoreactivity was substantially similar to that of the adults, with a less widespread neuronal distribution and a more developed fiber network. Ontogenetic presence of FMRFamide immunoreactivity in the nasal area has been linked to the presence of a nervus terminalis in this reptile.

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Endocrine Activity of the Corpus Luteum and Placenta during Pregnancy inChalcides chalcides(Reptilia, Squamata)

Cited by 42 publications

References 22 publications

Allantoplacental ultrastructure of an Andean population ofMabuya (Squamata, Scincidae)

Allantoplacental ultrastructure of an Andean population ofMabuya (Squamata, Scincidae)

Ovarian histology of the placentotrophic Mabuya mabouya (Squamata, Scincidae)

Localization of FMRFamide-Like Immunoreactivity in the Brain of the Viviparous Skink <i>(Chalcides chalcides)</i>

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