Mammary fat globules as a source of mRNA to model alterations in the expression of some milk component genes during lactation in bovines.

BACKGROUND: The milk's nutritional value is determined by its constituents, including fat, protein, carbohydrates, and minerals. The mammary gland's ability to produce milk is controlled by a complex network of genes. Thereby, the fat, protein, and lactose synthesis must be boost in milk to increase milk production efficiency. This can be accomplished by fusing genetic advancements with proper management practices. Therefore, this study aimed to investigate the association between the Lipoprotein lipase (LPL), kappa casein CSN3, and Glucose transporter 1 (GLUT1) genes expression levels and such milk components as fat, protein, and lactose in different dairy breeds during different stages of lactation. METHODS: To achieve such a purpose, 94 milk samples were collected (72 samples from 36 multiparous black-white and red-white Holstein-Friesian (HF) cows and 22 milk samples from 11 Egyptian buffaloes) during the early and peak lactation stages. The milk samples were utilized for milk analysis and genes expressions analyses using non- invasive approach in obtaining milk fat globules (MFGs) as a source of Ribonucleic acid (RNA). RESULTS: LPL and CSN3 genes expressions levels were found to be significantly higher in Egyptian buffalo than Holstein-Friesian (HF) cows as well as fat and protein percentages. On the other hand, GLUT1 gene expression level was shown to be significantly higher during peak lactation than early lactation. Moreover, lactose % showed a significant difference in peak lactation phase compared to early lactation phase. Also, fat and protein percentages were significantly higher in early lactation period than peak lactation period but lactose% showed the opposite pattern of Egyptian buffalo. CONCLUSION: Total RNA can be successfully obtained from MFGs. The results suggest that these genes play a role in glucose absorption and lactose synthesis in bovine mammary epithelial cells during lactation. Also, these results provide light on the differential expression of these genes among distinct Holstein-Friesian cow breeds and Egyptian buffalo subspecies throughout various lactation phases.

Silver Nanoparticles as Modulators of Myogenesis-Related Gene Expression in Chicken Embryos.

The present study was conducted to investigate the effects of colloidal nanoparticles of silver (Nano-Ag) on the expression of myogenesis-related genes in chicken embryos. The investigated genes included the members of the myogenic regulatory factors family (MRFs) and myocyte enhancer factor 2A (MEF2A) genes. A total of 200 fertilized broiler eggs (Indian River) were randomly distributed into four groups; non-injected control, injected control with placebo, treatment I in ovo injected with 20 ppm Nano-Ag, and treatment II in ovo injected with 40 ppm Nano-Ag. The eggs were then incubated for 21 days at the optimum temperature and humidity conditions. Breast muscle tissues were collected at the 5th, 8th, and 18th days of the incubation period. The mRNA expression of myogenic determination factor 1 (MYOD1), myogenic factor 5 (MYF5), myogenic factor 6 (MYF6), myogenin (MYOG), and MEF2A was measured at the three sampling points using real-time quantitative PCR, while MYOD1 protein expression was evaluated on day 18 using western blot. Breast muscle tissues were histologically examined on day 18 to detect the changes at the cellular level. Our results indicate that myogenesis was enhanced with the low concentration (20 ppm) of Nano-Ag due to the higher expression of MYOD1, MYF5, and MYF6 at the transcriptional level and MYOD1 at the translational level. Moreover, histological analysis revealed the presence of hyperplasia (31.4% more muscle fibers) in treatment I (injected with 20 ppm). Our findings indicate that in ovo injection of 20 ppm Nano-Ag enhances the development of muscles in chicken embryos compared with the 40-ppm dosage and provide crucial information for the use of silver nanoparticles in poultry production.

Associations between metabolic profiles, post-partum delayed resumption of ovarian function and reproductive performance in Egyptian buffalo: Roles of IGF-1 and antioxidants.

This study was conducted on 47 pluriparous pregnant Egyptian buffalo. Body condition score (BCS) was classified and blood samples were collected pre-partum and post-partum for estimation of IGF-1, hormonal, metabolic and antioxidants values. There was palpation per rectum and ultrasonography in addition to quantitation of progesterone (P4) and estradiol-17ß (E-17ß) for monitoring post-partum ovarian resumption. Reproductive indices were calculated 60, 90, 120 and 150 days post-partum. Based on the concentrations of P4 and E-17ß, buffalo were divided into ovulatory and non-ovulatory groups. The P4 and E-17ß were greater (P < 0.001) in ovulatory compared to non-ovulatory buffalo. The BCS and IGF-1 post-partum were greater (P =  0.024; 0.001, respectively) in ovulatory than non-ovulatory buffalo. Glucose and albumin were greater during pre- (P < 0.001; 0.013) and post-partum (P = 0.005; 0.003) periods in ovulatory than non-ovulatory buffalo. Post-partum, NEFA and BHBA concentrations were greater (P < 0.001) in non-ovulatory than ovulatory buffalo. The BUN concentrations were greater (P =  0.002) in non-ovulatory buffalo during pre- and post-partum periods. There were differences in GSH and SOD concentrations between groups (P < 0.001; 0.002, respectively). The BCS, albumin, IGF-1, GSH and SOD concentrations post-partum were negatively correlated with the delay of post-partum ovulation. The post-partum NEFA and BHBA concentrations, however, were positively correlated with delayed post-partum ovulation. Ovulatory buffalo had fewer (P < 0.01) days non-pregnant and for calving intervals as well as greater pregnancy rates than non-ovulatory buffalo. In conclusion, buffalo with delayed post-partum ovarian resumption were prone to have negative energy balance.