THE EXPRESSION OF SOX2, SOX17 AND STELLA IN OVARIES OF ADULT VIZCACHAS SUGGEST THE DE NOVO RENEWAL OF THE GERMINAL MASS

ALBAMONTE, MARIA ITATI; JAIME, VANINA; INSERRA, PABLO IGNACIO FELIPE; LEOPARDO, NOELIA PAOLA; DORFMAN BERTA VERONICA; ALFREDO D VITULLO; HALPERIN JULIA

Mar del Plata

Congreso; LXIII Reunion Anual de la Sociedad Argentina de Investigacion Clinica; 2018

Sociedad Argentina de Investigacion Clinica

<!-- /* Font Definitions */@font-face{font-family:Calibri;panose-1:2 15 5 2 2 2 4 3 2 4;mso-font-charset:0;mso-generic-font-family:auto;mso-font-pitch:variable;mso-font-signature:-520092929 1073786111 9 0 415 0;} /* Style Definitions */p.MsoNormal, li.MsoNormal, div.MsoNormal{mso-style-unhide:no;mso-style-qformat:yes;mso-style-parent:"";margin-top:0cm;margin-right:0cm;margin-bottom:10.0pt;margin-left:0cm;line-height:115%;mso-pagination:widow-orphan;font-size:11.0pt;font-family:Calibri;mso-ascii-font-family:Calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:Calibri;mso-fareast-theme-font:minor-latin;mso-hansi-font-family:Calibri;mso-hansi-theme-font:minor-latin;mso-bidi-font-family:"Times New Roman";mso-bidi-theme-font:minor-bidi;mso-ansi-language:ES;}.MsoChpDefault{mso-style-type:export-only;mso-default-props:yes;font-size:11.0pt;mso-ansi-font-size:11.0pt;mso-bidi-font-size:11.0pt;font-family:Calibri;mso-ascii-font-family:Calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:Calibri;mso-fareast-theme-font:minor-latin;mso-hansi-font-family:Calibri;mso-hansi-theme-font:minor-latin;mso-bidi-font-family:"Times New Roman";mso-bidi-theme-font:minor-bidi;mso-ansi-language:ES;}.MsoPapDefault{mso-style-type:export-only;margin-bottom:10.0pt;line-height:115%;}@page WordSection1{size:612.0pt 792.0pt;margin:72.0pt 90.0pt 72.0pt 90.0pt;mso-header-margin:36.0pt;mso-footer-margin:36.0pt;mso-paper-source:0;}div.WordSection1{page:WordSection1;}-->At each estral cycle, vizcachas exhibit a massive follicularrecruitment and ovulate up to 800 oocytes per cycle although the maximum sizeof an eventual litter is 2. Unlike most mammals, vizcachas show no signs ofapoptosis of their follicular structures, and so the ovary continuouslyremodels its architecture to maintain the availability of quiescent primordialfollicles throughout their reproductive life. Our laboratory has shown that thepool of primordial follicle remains relatively constant along the different reproductivestages despite the continuous massive recruitment and ovulations that characterizesthis species. Therefore, we hypothesize a permanent renewal of the ovariangerminal mass of the adult vizcachas (oogenesis de novo) tomaintain the follicular reserve. Herein, we examined the immunoexpression ofthe pluripotency markers Sox2 and Sox17 as wells as the germinality markerStella in ovaries of early-, mid-, term- and non-pregnant vizcachas. Oocytes ofprimordial follicles and nuclei of rounded stromal cells of early- andmid-pregnacy were positive for Sox2. Sox17 was observed in stromal cells locatednear the ovarian epithelium in the same groups of animals. Interestingly,although Stella was not detected in follicular structures, it exhibited amarked expression in certain conspicuous cellular packages within the stroma atall the evaluated reproductive stages. The expression of pluripotency andgerminality markers in ovaries of adult vizcachas indeed support the hypothesisof the de novo oogenesis. However, the scarce reactivity of Sox2and Sox17 is not sufficient to explain the  constant size of the pool of primordialfollicles throughout their reproductive life, suggesting that there should beother(s) factor(s) involved in inducing the renewal of the germinal mass inadult female vizcachas