title: Development and morphological changes in the vaginal closure membrane throughout gestation in Galea spixii (Rodentia: Caviidae).
abstract: Present research was carried out in order to perform the monitoring of development, recognizes the type of tissue and describes histological and cellular changes of the vaginal closure membrane (VCM) throughout pregnancy in Galea spixii. The results showed that at 20 days of gestation (DG), the VCM occludes completely the external vaginal ostium. Microscopically, the VCM presented juxtaposed cells, derived from the stratum germinative of the stratified epithelium of vaginal mucosa at 20 DG and areas with cell clusters with the presence of intercellular spaces in the final stages of pregnancy (40-50 DG). At 0 DG, the stratified epithelium of vaginal mucosa presented all strata but at 20 DG presented stratified epithelium without the stratum corneum and stratum granular and showed communicant junctions by desmosomes and interdigitations in the cell membrane compound the VCM. Gradually from 40 to 50 DG the stratum germinative became barely perceptible. Many cells showed apoptotic nuclei and emerged many intercellular spacing. So, the interdigitations and desmosomes were not observed. Here, it was demonstrated for the first time that the VCM is formed after the extinction of the stratum granular and corneum of the vaginal mucosa epithelium, with the proliferation of the cells of stratum germinative and communication and junction through desmosomes and interdigitations of these cells. At the end of pregnancy, cellular apoptosis; the spread of stratum germinative; and, absence of cellular communication and junction may be responsible for the weakening of the VCM and may assist the process of rupture of this membrane.
authors.affiliation: 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.
authors.forename: Amilton Cesar
authors.initials: AC
authors.lastname: dos Santos
authors.affiliation: Department of Animal Science, Federal Rural University of the Semiarid., BR-110 Km 47, Mossoró, RN, 59625-900, Brazil.
authors.forename: Gleidson Benevides
authors.initials: GB
authors.lastname: Oliveira
authors.affiliation: 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.
authors.forename: Diego Carvalho
authors.initials: DC
authors.lastname: Viana
authors.affiliation: 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.
authors.forename: Franceliusa Delys
authors.initials: FD
authors.lastname: Oliveira
authors.affiliation: 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.
authors.forename: Renata dos Santos
authors.initials: Rdos S
authors.lastname: Silva
authors.affiliation: 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.
authors.forename: Rose Eli Grassi
authors.initials: RE
authors.lastname: Rici
authors.affiliation: Department of Animal Science, Federal Rural University of the Semiarid., BR-110 Km 47, Mossoró, RN, 59625-900, Brazil.
authors.forename: Moacir Franco
authors.initials: MF
authors.lastname: de Oliveira
authors.affiliation: 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.
authors.forename: Antônio Chaves
authors.initials: AC
authors.lastname: de Assis-Neto
mesh_terms: D000818:Animals; D005260:Female; D009929:Organ Size / Q000502:physiology; D011247:Pregnancy; D012377:Rodentia / Q000033:anatomy & histology* / Q000502:physiology*; D014621:Vagina / Q000033:anatomy & histology* / Q000502:physiology*
keywords: caviidae; external vaginal ostium; pregnancy; rodents; vaginal membrane