Ovarian Structure in Mice Lines Selected for Weight |
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| Authors: | S F Bernardi G Brogliatti and M I Oyarzabal |
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| Institution: | Addresses of authors: Cátedra de Histología I y Embriología Básica, Facultad de Ciencias Veterinarias, Universidad Nacional de Rosario, Ovidio Lagos y Ruta 33, 2170 Casilda, Argentina;;Centro Genético Bovino EOLIA Sociedad Anónima, Paraná1097 10 "A", 1018 Buenos Aires, Argentina;;Cátedra de Producción Animal II, Facultad de Ciencias Veterinarias y Consejo de Investigaciones, Universidad Nacional de Rosario, Ovidio Lagos y Ruta 33, 2170 Casilda, Argentina;;Corresponding author: Tel.: (054) 03464 422050;fax: (054) 03464 422050;e-mail: |
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| Abstract: | Selection for body weight at 49 day of age ( s and h , downward selected lines; s' and h' , upward selected lines) affected reproductive traits in CF1 mice lines. The objective of this study was to compare ovarian structures in females of these lines, as well as in unselected controls (Line t ). The number of ovarian follicles ( N ), follicle diameter (FD), number of corpora lutea (CL), litter size (LS), and body weight ( W ), were recorded. There were significant differences among lines for N , FD, CL, LS and W ; means values for the lines with the greatest difference for post-pubertal females were: N s = 19.3 and N s' = 32.7; FD h' = 161.7 and FD s' = 178.2; CL h = 10.3 and CL s' = 21.9; LS s = 6.0 and LS h' = 11.1; W h = 18.9 and W s' = 32.4. There were also differences between positive lines; Line s' had a higher proportion of large follicles in pre-pubertal females, a greater capacity to convert these follicles into CL, but a lower capacity to maintain embryos until term than Line h' . For negative lines, Line h apparently had a reduced incidence of embryonic loss when compared with Line s . In conclusion, selection for body weight modified ovarian structure, as well as reproductive efficiency. |
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