Morphometric Analysis of the Scleral Bony Ring with Different Numbers of Ossicles in the Eye of Coturnix Coturnix Japonica

The scleral bony ring (s. b. r.) of Coturnix coturnix japonica was examined and evaluated mor-phometrically in its characteristic formations (scleral ossicles, overlapping sectors). The modal class14–14, the most representative, was compared to others having minor or major numbers of ossicles with complex or simple overlaps in the left and right eyes. It was observed that the ossicles, numbered as in the literature, are ordered in a characteristic manner to form the s. b. r. The ossicle dimensions are different and numbers 4 and 7 are always smaller and larger. The s. b. r. with different numbers of ossicles compared to the model class14–14 (0,0) showed an evident compensatory behaviour in all classes. In fact, when the ossicle number decreased, single ossicle area increased, retaining a constant s. b. r. area.     

Apoptotic Cell Death, bax and bcl-2 Expression During Sheep Mammary Gland Involution

Involution in ovine mammary tissue was studied by light and electron microscopy, and bax and bcl-2 protein distribution was examined by immunohistochemistry from the last day of lactation until the 8th day of drying off. The mammary gland alveoli were examined and the area of glandular epithelium was evaluated morphometrically. Regression of mammary gland epithelium by apoptosis was first identified 2 days after the end of lactation, and increased until day 8. Bax protein was detected throughout this period and was highest on the eighth day. A weak positive reaction for bcl-2 was observed only on days 1 and 8 after cessation of lactation. It is concluded that sheep mammary gland involution involves cell death by apoptosis and that bcl-2 gene family members are involved in the process.     

Mammary cell turnover in lactating ewes is modulated by changes of energy fuels

The study of cell turnover of mammary gland helps to gain understanding of the subtle modulation that largely determines milk production. To evaluate the effect of diet composition on cell turnover of mammary gland, pluriparous sheep were allotted to three experimental groups and fed from day 33 after lambing a control diet (BD), a high starch (HS) diet or a high fat (HF) diet. Biopsies of mammary gland tissue were collected at 50 days after lambing for in situ detection of cell death and RT-PCR analysis of bax, bcl-2, caspase-3 and GST expressions. Both apoptotic and proliferation indexes were significantly higher (P<0.05) in the BD group compared to HS and HF groups. The relative expressions of GST were significantly greater (P<0.05) in HF group compared to the BD and HS groups. There was a significant increase in the ratio of bcl-2 to bax mRNA in the HS and HF groups. Availability of energy substrates for mammary gland can interfere with the cell fate, modulating genes involved in the control of oxidative stress which, in turn, can indirectly regulate cell apoptosis and proliferation.     

Effect of Natural Antioxidants on Superoxide Dismutase and Glutathione Peroxidase mRNA Expression in Leukocytes from Periparturient Dairy Cows

During the peripartum period, high-yielding dairy cows experience metabolic stress, which alters their homeostasis and exposes the cows to illness. The aim of this study was to quantify the expression levels of genes involved in antioxidant defences during the transition period in the blood of dairy cows and to evaluate the regulative activity on these genes of natural antioxidants in the diet. Three groups of 7 heifers each, at the 7th month of pregnancy, were used. Starting from 3 weeks before the expected calving date (–22 days), the three groups were allotted to the following experimental treatments: control (CTR, basal diet); lycopene (LYC, basal diet + lycopene 540 mg/day) and grape polyphenols (POL, basal diet + grape polyphenols 10 g/day). Blood was sampled at 22 and 8 days before and 8, 15 and 22 after calving and analysed for the expression level of glutathione peroxidase (GPx) and superoxide dismutase (Cu/ZnSOD) using the real-time PCR technique with LUX (Light Upon eXtension) fluorogenic primers. During the peripartum period (–22 days until + 22 days from calving), Cu/ ZnSOD mRNA expression decreased (p<0.05) in the CTR and LYC groups, but increased at 15 days after calving in the POL group. No significant differences were found in GPx mRNA expression. The results suggest that grape polyphenols may have a controlling effect on peripartum metabolic stress through modulation of superoxide dismutase expression.     

Apoptosis and Expression of Related Proteins in Mammary Gland of Heifers during Early Lactation

Veterinary Research Communications -     

BCL-2 family of proteins and mammary cellular fate

This review focuses on the pro-apoptotic and anti-apoptotic Bcl-2 family members involved in apoptosis, which is the predominant process controlling cell remodelling during post-lactational mammary gland involution. The members of the Bcl-2 protein family, whose expression levels are under the control of lactogenic hormones, internally control this mechanism also during lactation. They can physically interact with each other, sometimes in an antagonistic manner. Mammary glands undergo repeated cycles of structural development, functional differentiation and regression, therefore provide a unique model for investigating this family of proteins that regulate the fate of the secretory cells and consequently milk yield. The involvement of Bcl-2 family members is reviewed in mammary tissue during morphogenesis, at different stages of lactation cycle and in comparison with dairy and laboratory animals.