1
|
de Oliveira GB, de Araújo Júnior HN, de Moura CEB, Favaron PO, Pereira AF, de Oliveira MF. Placental development in the early stages of red-rumped agouti pregnancy ( Dasyprocta leporina Linnaeus, 1758). J Vet Sci 2023; 24:e49. [PMID: 38031643 PMCID: PMC10556294 DOI: 10.4142/jvs.22323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 04/18/2023] [Accepted: 05/17/2023] [Indexed: 12/01/2023] Open
Abstract
BACKGROUND Hystricomorpha rodents display a similar placentation model to humans. The present study was carried out considering the scarcity of information concerning the placental development in agouti. OBJECTIVE Describe the microscopy of the placenta, subplacenta and yolk sac of agoutis in early pregnancy and report on the inversion of the yolk sac. METHODS Fifteen females between the 14th-32nd day of gestation were used following euthanasia. Gestational buttons were collected, fixed, processed, stained to optical microscopy or immunohistochemistry. RESULTS Chorioallantoic placenta (CP) ranged from conical to a half-sphere, as follows: from the 14th to 17th day, the CP displays an inverted "V" shape, predominantly formed by cytotrophoblasts; from 20 to 22 days, formed almost entirely by cytotrophoblasts; at 28 days, a half sphere, with distinct lobes and interlobular area, numerous maternal gaps delimited by syncytiotrophoblasts and trophoblast giant cells; at 32 days, globose and undergoing the maturation process. Subplacenta, located between decidua and CP, initially presents septa consisting of simple columnar epithelium and after 17 days, comprising stratified epithelium. Visceral yolk sac (VYS) is attached to two CP projections between 14 and 17 days, formed by a simple cubic epithelium and inverted. Between 20 and 22 days, the epithelium displays apical villous projections with cytoplasmic vacuoles and a vascularized mesoderm. After the 24th day, the VYS near the placenta is pleated, very vascularized and villous, with decreased villi sizes further away from the placenta. CONCLUSION The agouti CP displays similar characteristics to other hystricomorpha, including placenta lobulation, a subplacenta and an inverted vitelline placenta.
Collapse
Affiliation(s)
| | | | | | | | | | - Moacir Franco de Oliveira
- Department of Animal Science, Universidade Federal Rural do Semi-Árido, Mossoró, RN 59.625-900, Brasil
| |
Collapse
|
2
|
Santos AC, Conley AJ, Oliveira MF, Assis Neto AC. Steroidogenesis during prenatal testicular development in Spix's cavy Galea spixii. Reprod Fertil Dev 2021; 33:392-400. [PMID: 33685580 DOI: 10.1071/rd20293] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2020] [Accepted: 01/28/2021] [Indexed: 12/21/2022] Open
Abstract
Spix's cavy is a potentially good experimental model for research on reproductive biology and sexual development. The aim of the present study was to evaluate the ontogeny of the steroidogenic enzymes involved in testicular androgen synthesis during prenatal development. Testes were investigated on Days 25, 30, 40 and >50 of gestation. Immunohistochemistry and immunoblotting were used to establish the site and relative amount of androgenic enzymes, including 5α-reductase, cytosolic 17β-hydroxysteroid dehydrogenase (17β-HSDI) and mitochondrial microsomal 3β-hydroxysteroid dehydrogenase (3β-HSDII), throughout prenatal development. The testicular parenchyma began to organise on Day 25 of gestation, with the development of recognisable testicular cords. The mesonephros was established after Day 25 of gestation and the ducts differentiated to form the epididymis, as testicular cords were beginning to proliferate and the interstitium to organise by Day 30 of gestation, continuing thereafter. The androgen-synthesising enzymes 5α-reductase, 17β-HSDI and 3β-HSDII were evident in Leydig cells as they differentiated at all subsequent gestational ages studied. In addition, immunoblotting showed an increase in immunoreactivity for the enzymes at Days 30 and 40 of gestation (P<0.05) and a decrease at Day 50 of gestation (P<0.05). It is concluded that the increase in androgenic enzymes in Leydig cells coincides with the functional differentiation of the testes, and with the stabilisation and differentiation of mesonephric ducts forming the epididymis.
Collapse
Affiliation(s)
- A C Santos
- School of Veterinary Medicine and Animal Science, University of Sao Paulo. Av. Prof. Dr. Orlando de Marques Paiva, 87; ZC 05508 270; São Paulo - Brazil
| | - A J Conley
- Population Health & Reproduction, School of Veterinary Medicine, University of California, 3223 VM3B, Davis, CA 95616, USA
| | - M F Oliveira
- Department of Animal Science, Federal Rural University of Semiarid. Av. Francisco Mota, 572, 59625 900, Mossoro, Rio Grande do Norte, Brazil
| | - A C Assis Neto
- School of Veterinary Medicine and Animal Science, University of Sao Paulo. Av. Prof. Dr. Orlando de Marques Paiva, 87; ZC 05508 270; São Paulo - Brazil; and Corresponding author.
| |
Collapse
|
3
|
Mario LC, Morais MP, Borghesi J, Favaron PO, Oliveira FD, Anunciação ARA, Agopian RG, Gomes SA, Miglino MA. Development of urinary organs in domestic cat during the embryonic and fetal periods. Microsc Res Tech 2018; 81:1286-1294. [PMID: 30341968 DOI: 10.1002/jemt.23135] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 08/09/2018] [Accepted: 08/27/2018] [Indexed: 11/06/2022]
Abstract
The embryonic origin of the urogenital system came from the intermediate mesoderm. Kidney development involves three successive renal systems with a fast chronological overlap: the pronephro, the mesonephro, and the metanephro. Due to the lack of specific knowledge about this system in cats the present work aimed to describe their urinary organs development, focusing on the structures seen in pronephro, mesonephro, and metanephro during the embryonic and fetal stages of development. The techniques used in this study were: light microscopy, immunohistochemistry, scanning electron microscopy, and transmission electron microscopy. For that, embryos and fetuses from 12 pregnant mixed-breed domestic cats in different gestational stages were used to describe the proposed organs. The pronephro is present at early stages of embryonary development in embryos from 15 to 19 days with the presence of pronephro's corpuscles, ducts and tubules. The mesonephro is found, in general, between days 17 and 37, and contains mesonephric ducts, mesonephric tubules, and glomeruli. The metanephro is seen since 21 days of pregnancy with the presence of glomeruli, proximal and distal contorted tubules and at day 37, the cortex-medullary region is already differentiated. The evaluation of these structures enhances the knowledge about embryology of the urinary system in cats, aiding a better anatomical understanding of the system in the specie allowing the correlation with other species.
Collapse
Affiliation(s)
- Lara C Mario
- Sector of Wild and Domestic Animals Anatomy, College of Veterinary Medicine and Animal Science of the University of Sao Paulo FMVZ/USP, São Paulo, Brazil
| | - Maiara P Morais
- Sector of Wild and Domestic Animals Anatomy, College of Veterinary Medicine and Animal Science of the University of Sao Paulo FMVZ/USP, São Paulo, Brazil
| | - Jessica Borghesi
- Sector of Wild and Domestic Animals Anatomy, College of Veterinary Medicine and Animal Science of the University of Sao Paulo FMVZ/USP, São Paulo, Brazil
| | - Phelipe O Favaron
- Sector of Wild and Domestic Animals Anatomy, College of Veterinary Medicine and Animal Science of the University of Sao Paulo FMVZ/USP, São Paulo, Brazil
| | - Franceliusa D Oliveira
- Sector of Wild and Domestic Animals Anatomy, College of Veterinary Medicine and Animal Science of the University of Sao Paulo FMVZ/USP, São Paulo, Brazil
| | - Adriana R A Anunciação
- Sector of Wild and Domestic Animals Anatomy, College of Veterinary Medicine and Animal Science of the University of Sao Paulo FMVZ/USP, São Paulo, Brazil
| | - Rafael G Agopian
- Sector of Wild and Domestic Animals Anatomy, College of Veterinary Medicine and Animal Science of the University Santo Amaro University UNISA, São Paulo, Brazil
| | - Samirah A Gomes
- Departament of Clinical Medicine, College of Medicine of the University of Sao Paulo FM/USP, São Paulo, Brazil
| | - Maria A Miglino
- Sector of Wild and Domestic Animals Anatomy, College of Veterinary Medicine and Animal Science of the University of Sao Paulo FMVZ/USP, São Paulo, Brazil
| |
Collapse
|
4
|
dos Santos AC, Conley AJ, de Oliveira MF, Oliveira GB, Viana DC, Assis Neto ACD. Immunolocalization of steroidogenic enzymes in the vaginal mucous of Galea spixii during the estrous cycle. Reprod Biol Endocrinol 2017; 15:30. [PMID: 28438170 PMCID: PMC5404681 DOI: 10.1186/s12958-017-0248-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2017] [Accepted: 04/18/2017] [Indexed: 12/03/2022] Open
Abstract
BACKGROUND The synthesis of sex steroids is controlled by several enzymes such as17α-hydroxylase cytochrome P450 (P450c17) catalyzing androgen synthesis and aromatase cytochrome P450 (P450arom) catalyzing estrogen synthesis, both of which must complex with the redox partner NADPH-cytochrome P450 oxidoreductase (CPR) for activity. Previous studies have identified expression of steroidogenic enzymes in vaginal tissue, suggesting local sex steroid synthesis. The current studies investigate P450c17, P450aromatase and CPR expression in vaginal mucosa of Galea spixii (Spix cavy) by immuno-histochemical and western immunoblot analyses. METHODS Stages of estrous cyclicity were monitored by vaginal exfoliative cytology. After euthanasia, vaginal tissues were retrieved, fixed and frozen at diestrus, proestrus, estrus and metestrus. The ovaries and testis were used as positive control tissues for immunohistochemistry. RESULTS Data from cytological study allowed identification of different estrous cycle phases. Immunohistochemical analysis showed different sites of expression of steroidogenic enzymes along with tissue response throughout different phases of the estrous cycle. However, further studies are needed to characterize the derived hormones synthesized by, and the enzymes activities associated with, vaginal tissues. CONCLUSION Current results not only support the expression of enzymes involved in sex steroid synthesis in the wall of the vagina, they also indicate that expression changes with the stage of the cycle, both the levels and types of cells exhibiting expression. Thus, changes in proliferation of vaginal epithelial cells and the differentiation of the mucosa may be influenced by local steroid synthesis as well as circulating androgens and estrogens.
Collapse
Affiliation(s)
- Amilton Cesar dos Santos
- 0000 0004 1937 0722grid.11899.38Department of Surgery, School of Veterinary Medicine and Animal Science, University of São Paulo, Av. Prof. Dr. Orlando Marques de Paiva, 87 ZC 05508-270 São Paulo, Brazil
| | - Alan James Conley
- 0000 0004 1936 9684grid.27860.3bPopulation Health & Reproduction, School of Veterinary Medicine, University of California, Davis, 95616 USA
| | - Moacir Franco de Oliveira
- 0000 0004 0644 0007grid.412393.eDepartment of Veterinary Medicine, Universidade Federal Rural do Semiárido, Mossoró, 59625-900 Brazil
| | - Gleidson Benevides Oliveira
- 0000 0004 0644 0007grid.412393.eDepartment of Veterinary Medicine, Universidade Federal Rural do Semiárido, Mossoró, 59625-900 Brazil
| | - Diego Carvalho Viana
- 0000 0004 1937 0722grid.11899.38Department of Surgery, School of Veterinary Medicine and Animal Science, University of São Paulo, Av. Prof. Dr. Orlando Marques de Paiva, 87 ZC 05508-270 São Paulo, Brazil
| | - Antônio Chaves de Assis Neto
- 0000 0004 1937 0722grid.11899.38Department of Surgery, School of Veterinary Medicine and Animal Science, University of São Paulo, Av. Prof. Dr. Orlando Marques de Paiva, 87 ZC 05508-270 São Paulo, Brazil
| |
Collapse
|
5
|
dos Santos AC, Viana DC, Oliveira GB, Silva RS, Oliveira MF, Assis-Neto AC. Follicular development and morphological changes in the vaginal epithelium during the estrous cycle ofGalea spixii. Microsc Res Tech 2016; 80:167-176. [DOI: 10.1002/jemt.22784] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Revised: 09/01/2016] [Accepted: 09/15/2016] [Indexed: 11/06/2022]
Affiliation(s)
- Amilton Cesar dos Santos
- Department of Anatomy of Domestic and Wild Animals, School of Veterinary Medicine and Animal Sciences; Av. Prof. Dr. Orlando Marques de Paiva 87, Cidade Universitária Sao Paulo SP 05508-270 Brazil
| | - Diego Carvalho Viana
- Department of Anatomy of Domestic and Wild Animals, School of Veterinary Medicine and Animal Sciences; Av. Prof. Dr. Orlando Marques de Paiva 87, Cidade Universitária Sao Paulo SP 05508-270 Brazil
| | - Gleidson Benevides Oliveira
- Department of Animal Science; Federal Rural University of the Semiarid; BR-110 Km 47 Mossoró RN 59625-900 Brazil
| | - Renata Santos Silva
- Department of Anatomy of Domestic and Wild Animals, School of Veterinary Medicine and Animal Sciences; Av. Prof. Dr. Orlando Marques de Paiva 87, Cidade Universitária Sao Paulo SP 05508-270 Brazil
| | - Moacir Franco Oliveira
- Department of Animal Science; Federal Rural University of the Semiarid; BR-110 Km 47 Mossoró RN 59625-900 Brazil
| | - Antônio Chaves Assis-Neto
- Department of Anatomy of Domestic and Wild Animals, School of Veterinary Medicine and Animal Sciences; Av. Prof. Dr. Orlando Marques de Paiva 87, Cidade Universitária Sao Paulo SP 05508-270 Brazil
| |
Collapse
|
6
|
Silva FMDOE, Alcantara D, Carvalho RC, Favaron PO, Santos ACD, Viana DC, Miglino MA. Development of the central nervous system in guinea pig (Cavia porcellus, Rodentia, Caviidae). PESQUISA VETERINARIA BRASILEIRA 2016. [DOI: 10.1590/s0100-736x2016000800013] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Abstract: This study describes the development of the central nervous system in guinea pigs from 12th day post conception (dpc) until birth. Totally, 41 embryos and fetuses were analyzed macroscopically and by means of light and electron microscopy. The neural tube closure was observed at day 14 and the development of the spinal cord and differentiation of the primitive central nervous system vesicles was on 20th dpc. Histologically, undifferentiated brain tissue was observed as a mass of mesenchymal tissue between 18th and 20th dpc, and at 25th dpc the tissue within the medullary canal had higher density. On day 30 the brain tissue was differentiated on day 30 and the spinal cord filling throughout the spinal canal, period from which it was possible to observe cerebral and cerebellar stratums. At day 45 intumescences were visualized and cerebral hemispheres were divided, with a clear division between white and gray matter in brain and cerebellum. Median sulcus of the dorsal spinal cord and the cauda equina were only evident on day 50. There were no significant structural differences in fetuses of 50 and 60 dpc, and animals at term were all lissencephalic. In conclusion, morphological studies of the nervous system in guinea pig can provide important information for clinical studies in humans, due to its high degree of neurological maturity in relation to its short gestation period, what can provide a good tool for neurological studies.
Collapse
|
7
|
Santos AC, Viana DC, Bertassoli BM, Vasconcelos BG, Oliveira DM, Rici REG, Oliveira MF, Miglino MA, Assis-Neto AC. Adrenal glands of Spix's yellow-toothed cavy (Galea spixii, Wagler, 1831): morphological and morphometric aspects. BRAZ J BIOL 2016; 76:645-55. [DOI: 10.1590/1519-6984.23514] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Accepted: 04/28/2015] [Indexed: 12/17/2022] Open
Abstract
Abstract Considering the physiological importance and need of greater morphophysiological knowledge of adrenal glands, the aims of present study were compare the morphometric data between left and right adrenal of male and female; perform a histological, scanning and transmission electron microscopy study showing tissue constitution of glands; finally, in order to define the presence and correct site of the cytochrome P450c17 expression in adrenal glands, immunohistochemical study of this enzyme was performed in 18 adrenal glands (right n=9 and left n=9) of nine adult Galea spixii (four males and five females). Right adrenal was more cranially positioned than left adrenal; dimensions (weight, length and width) of right adrenal was larger than left adrenal; no differences between male and female body and adrenal measurements were found; the morphology of cells and different amounts of lipid droplets may be related to the different demands of steroid hormones production, related to each zone of the adrenal cortex; and, the cytochrome P450c17 immunolocalization in fasciculate and reticular zone may be related with synthesis of 17-hydroxy-pregnenolone, 17-hydroxy-progesterone, dehydroepiandrosterone or androstenedione.
Collapse
|
8
|
dos Santos AC, Oliveira GB, Viana DC, Oliveira FD, Silva RDS, Rici REG, de Oliveira MF, de Assis-Neto AC. Development and morphological changes in the vaginal closure membrane throughout gestation inGalea spixii(Rodentia: Caviidae). Microsc Res Tech 2016; 79:359-64. [DOI: 10.1002/jemt.22638] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Accepted: 01/23/2016] [Indexed: 11/10/2022]
Affiliation(s)
- Amilton Cesar dos Santos
- Department Anatomy of Domestic and Wild Animals; School of Veterinary Medicine and Animal Sciences. Av. Prof. Dr. Orlando Marques De Paiva 87, Cidade Universitária; Sao Paulo SP 05508-270 Brazil
| | - Gleidson Benevides Oliveira
- Department of Animal Science; Federal Rural University of the Semiarid.; BR-110 Km 47 Mossoró RN 59625-900 Brazil
| | - Diego Carvalho Viana
- Department Anatomy of Domestic and Wild Animals; School of Veterinary Medicine and Animal Sciences. Av. Prof. Dr. Orlando Marques De Paiva 87, Cidade Universitária; Sao Paulo SP 05508-270 Brazil
| | - Franceliusa Delys Oliveira
- Department Anatomy of Domestic and Wild Animals; School of Veterinary Medicine and Animal Sciences. Av. Prof. Dr. Orlando Marques De Paiva 87, Cidade Universitária; Sao Paulo SP 05508-270 Brazil
| | - Renata dos Santos Silva
- Department Anatomy of Domestic and Wild Animals; School of Veterinary Medicine and Animal Sciences. Av. Prof. Dr. Orlando Marques De Paiva 87, Cidade Universitária; Sao Paulo SP 05508-270 Brazil
| | - Rose Eli Grassi Rici
- Department Anatomy of Domestic and Wild Animals; School of Veterinary Medicine and Animal Sciences. Av. Prof. Dr. Orlando Marques De Paiva 87, Cidade Universitária; Sao Paulo SP 05508-270 Brazil
| | - Moacir Franco de Oliveira
- Department of Animal Science; Federal Rural University of the Semiarid.; BR-110 Km 47 Mossoró RN 59625-900 Brazil
| | - Antônio Chaves de Assis-Neto
- Department Anatomy of Domestic and Wild Animals; School of Veterinary Medicine and Animal Sciences. Av. Prof. Dr. Orlando Marques De Paiva 87, Cidade Universitária; Sao Paulo SP 05508-270 Brazil
| |
Collapse
|
9
|
Santos AC, Viana DC, Bertassoli BM, Oliveira GB, Oliveira DM, Bezerra FV, Oliveira MF, Assis-Neto AC. Characterization of the estrous cycle in Galea spixii(Wagler, 1831). PESQUISA VETERINARIA BRASILEIRA 2015. [DOI: 10.1590/s0100-736x2015000100017] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The Galea spixii inhabits semiarid vegetation of Caatinga in the Brazilian Northeast. They are bred in captivity for the development of researches on the biology of reproduction. Therefore, the aim of this study is characterize the estrous cycle of G. spixii, in order to provide information to a better knowledge of captive breeding of the species. The estrous cycle was monitored by vaginal exfoliative cytology in 12 adult females. After the detection of two complete cycles in each animal, the same were euthanized. Then, histological study of the vaginal epithelium, with three females in each phase of the estrous cycle was performed; five were paired with males for performing the control group for estrous cycle phases, and three other were used to monitor the formation and rupture of vaginal closure membrane. By vaginal exfoliative cytology, predominance of superficial cells in estrus, large intermediate cells in proestrus, intermediate and parabasal cells, with neutrophils, in diestrus and metestrus respectively was found. Estrus was detected by the presence of spermatozoa in the control group. By histology, greater proliferation of the vaginal epithelium in proestrus was observed. We conclude that the estrous cycle of G. spixii lasts 15.8 ± 1.4 days and that the vaginal closure membrane develops until complete occlusion of the vaginal ostium, breaking after few days. Future studies may reveal the importance of this fact for the reproductive success of this animal.
Collapse
|
10
|
Placental Evolution within the Supraordinal Clades of Eutheria with the Perspective of Alternative Animal Models for Human Placentation. ACTA ACUST UNITED AC 2014. [DOI: 10.1155/2014/639274] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Here a survey of placental evolution is conducted. Placentation is a key factor for the evolution of placental mammals that had evolved an astonishing diversity. As a temporary organ that does not allow easy access, it is still not well understood. The lack of data also is a restriction for better understanding of placental development, structure, and function in the human. Animal models are essential, because experimental access to the human placenta is naturally restricted. However, there is not a single ideal model that is entirely similar to humans. It is particularly important to establish other models than the mouse, which is characterised by a short gestation period and poorly developed neonates that may provide insights only for early human pregnancy. In conclusion, current evolutionary studies have contributed essentially to providing a pool of experimental models for recent and future approaches that may also meet the requirements of a long gestation period and advanced developmental status of the newborn in the human. Suitability and limitations of taxa as alternative animal models are discussed. However, further investigations especially in wildlife taxa should be conducted in order to learn more about the full evolutionary plasticity of the placenta system.
Collapse
|
11
|
Borghesi J, Mario LC, Rodrigues MN, Favaron PO, Miglino MA. Immunoglobulin Transport during Gestation in Domestic Animals and Humans—A Review. ACTA ACUST UNITED AC 2014. [DOI: 10.4236/ojas.2014.45041] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
12
|
Vasconcelos BG, Favaron PO, Miglino MA, Mess AM. Development and morphology of the inverted yolk sac in the guinea pig (Cavia porcellus). Theriogenology 2013; 80:636-41. [DOI: 10.1016/j.theriogenology.2013.06.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2013] [Revised: 06/05/2013] [Accepted: 06/06/2013] [Indexed: 10/26/2022]
|
13
|
Vale AM, Oliveira GB, Favaron PO, Miglino MA, Paula VV, Silva AR, Oliveira MF. Dinâmica da inversão do saco vitelino em preás (Galea spixii Wagler, 1831). PESQUISA VETERINARIA BRASILEIRA 2013. [DOI: 10.1590/s0100-736x2013000800014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
O objetivo deste trabalho foi estudar o período de inversão do saco vitelino bem como a dinâmica resultante deste processo na gestação inicial em preás, utilizando-se microscopia de luz, microscopia eletrônica de varredura e de transmissão. No décimo segundo dia de gestação observou-se o desenvolvimento dos endodermas parietal e visceral delimitando a cavidade do saco vitelino. O endoderma parietal foi evidenciado revestindo a superfície fetal da placenta corioalantoidea bem como contornando o espaço delimitado pela decídua capsular. Estes endodermas apresentaram formato prismático e encontraram-se separados do trofoblasto por uma desenvolvida membrana de Reichert. Já o endoderma visceral continha vasos vitelínicos e possuía vilosidades apenas em determinadas áreas. No décimo quarto dia de gestação verificou-se a inversão do saco vitelino, caracterizada pela degeneração do endoderma parietal e trofoblasto mural, associado ao desaparecimento gradual da membrana de Reichert. Como consequência deste fenômeno, o endoderma visceral passou a constituir uma interface com o epitélio uterino. Após a inversão, o endoderma parietal que permaneceu íntegro foi aquele que se apoiava na superfície da placenta corioalantóidea, apresentando células em formato colunar alto e característica de epitélio pseudoestratificado. O endoderma visceral apresentou numerosas vilosidades apicais principalmente em regiões próximas a placenta corioalantóidea. Com o contínuo desenvolvimento do embrião e placenta corioalantóidea, observou-se o surgimento de importante área de aposição entre os endodermas visceral e parietal. A inversão do saco vitelino representou uma disposição anatômica favorável ao desenvolvimento embrionário, além de ser uma característica evolutiva nesta espécie de roedor.
Collapse
|