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Antosik P.,University of Life Sciences in Poznan | Kempisty B.,Poznan University of Medical Sciences | Jackowska M.,University of Life Sciences in Poznan | Piotrowska H.,Poznan University of Medical Sciences | And 6 more authors.
Animal Biology | Year: 2011

Gap junction connections are formed by proteins which play an important role in oocyte developmental competency but there is little information on the relationship between follicle size and the expression of genes encoding these proteins. The aim of this study was to investigate the potential association between follicle size and the levels of Cdk4 and Cx43 proteins using western blot analysis and confocal microscopic observations. Cumulus-oocyte complexes (COCs) were collected from puberal gilts (n = 20) of large (>5 mm), medium (3-5 mm), and small (<3 mm) follicles, and stained with BCB. BCB+ COCs, which had finished their growth phase, were cultured in TCM 199 for 44 h. Western blot analysis revealed an increased level of Cdk4 protein in oocytes isolated from large follicles as compared to medium (P < 0.05) and small (P < 0.01) ones. We did not detect differences in Cx43 protein levels in oocytes collected from any follicle class. Confocal microscopic observation revealed a specific membrane and zona pellucida localization of Cdk4 protein in oocytes isolated from large follicles, but an exclusively cytoplasmatic distribution of Cdk4 in oocytes from smaller follicle categories. The effect of follicular size on Cdk4 is indicated by the higher level of Cdk4 protein in oocytes isolated from large follicles and its variable distribution - perhaps resulting from a specific translocation mechanism - in the membrane, zona pellucida, and cytoplasm. IVM may also have a significant effect on Cdk4, as seen from the considerable difference in the expression and localization of Cdk4 protein in oocytes after IVM. © 2011 Koninklijke Brill NV, Leiden. Source


Egerszegi I.,Research Institute for Animal Breeding and Nutrition | Alm H.,FBN Research Institute for the Biology of Farm Animals | Ratky J.,Research Institute for Animal Breeding and Nutrition | Heleil B.,Kafr El Sheikh University | And 2 more authors.
Reproduction, Fertility and Development | Year: 2010

The aim of the present study was to investigate the developmental competence, mitochondrial characteristics and chromatin status of immature follicular porcine oocytes selected for their glucose-6-phosphate dehydrogenase (G6PDH) activity by brilliant cresyl blue (BCB) staining. In Experiment 1, the oocyte parameters were determined in parallel right after BCB staining (T 0), after 22 h of in vitro maturation (IVM) (T22) and after 44 h of IVM (T44) (n=496). BCB-stained oocytes (BCB+) at T 0 were characterised by fibrillated chromatin filaments in their germinal vesicles (GV) and diakinesis stages whereas unstained (BCB-) oocytes at T0 contained in their GV mainly condensed stages of chromatin (P <0.05). After 22 h of IVM BCB+ oocytes showed a prominent chromatin configuration of metaphase I and after 44 h the majority developed a M II nuclear configuration in contrast to the BCB- group (P <0.0001). Differences were also observed between the two oocyte populations in their mitochondrial activity (P <0.05). At the beginning of IVM BCB+ oocytes were characterised by high mitochondrial activity in their cytoplasm. The BCB+ oocytes showed clear visible homogenous distributions of mitochondria (P <0.005) and contained more aggregated clusters of mitochondria in contrast to BCB- oocytes (P <0.005). In Experiment 2, 318 oocytes were tested for their G6PDH activity and introduced to IVM and IVF. Only oocytes from the BCB+ group, which were matured after 44 h up to the stage of M II (81.6%) were fertilised (17.4%), penetrated (46%) or activated (15.6%) after IVF. These results indicate a relationship between the G6PDH activity of porcine oocytes before IVM and their subsequent nuclear development, mitochondrial activity and aggregation. © 2010 CSIRO. Source


Herdmann A.,FBN Research Institute for the Biology of Farm Animals | Nuernberg K.,FBN Research Institute for the Biology of Farm Animals | Martin J.,State Institute for Agriculture and Fishing Research | Nuernberg G.,FBN Research Institute for the Biology of Farm Animals | Doran O.,University of the West of England
Animal | Year: 2010

This study investigated the effects of dietary linolenic acid (C18:3n-3) v. linoleic acid (C18:2n-6) on fatty acid composition and protein expression of key lipogenic enzymes, acetyl-CoA carboxylase (ACC), stearoyl-CoA desaturase (SCD) and delta 6 desaturase (6d) in longissimus muscle and subcutaneous adipose tissue of bulls. Supplementation of the diet with C18:3n-3 was accompanied by an increased level of n-3 fatty acids in muscle which resulted in decrease of n-6/n-3 ratio. The diet enriched with n-3 polyunsaturated fatty acids (PUFAs) significantly inhibited SCD protein expression in muscle and subcutaneous adipose tissue, and reduced the 6d expression in muscle. There was no significant effect of the diet on ACC protein expression. Inhibition of the 6d expression was associated with a decrease in n-6 PUFA level in muscles, whereas repression of SCD protein was related to a lower oleic acid (C18:1 cis-9) content in the adipose tissue. Expression of ACC, SCD and 6d proteins was found to be relatively higher in subcutaneous adipose tissue when compared with longissimus muscle. It is suggested that dietary manipulation of fatty acid composition in ruminants is mediated, at least partially, through the regulation of lipogenic enzymes expression and that regulation of the bovine lipogenic enzymes expression is tissue specific. © 2010 The Animal Consortium. Source


Alm H.,FBN Research Institute for the Biology of Farm Animals | Kuhlmann S.,FBN Research Institute for the Biology of Farm Animals | Langhammer M.,FBN Research Institute for the Biology of Farm Animals | Tuchscherer A.,FBN Research Institute for the Biology of Farm Animals | And 2 more authors.
Journal of Reproduction and Development | Year: 2010

The aim of this study was to evaluate the prevalence of follicles with more than one oocyte (polyovular follicles, POFs) in mouse lines selected for high fecundity. The ovaries of 18 mice, 6 each from 3 different lines, were examined to evaluate the number of POFs and the follicular histology. Polyovular follicles were observed in the two high fecundity breeds, FL1 and FL2, as well as in the unselected control line, DUKsi. The highest number of POFs per ovary (27.0 ± 7.2) was found in the FL1 line. The FL2 and DUKsi lines had 1.9 ± 0.7 and 0.6 ± 0.3 polyovular follicles per ovary, respectively. Most of the POFs contained 2 oocytes (>80%), but occasionally follicles containing up to 7 oocytes were observed. Follicles with more than 2 oocytes were observed in the FL1 line only. © 2010 by the Society for Reproduction and Development. Source

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