The crucial role of CTCF in mitotic progression during early development of sea urchin.

CCCTC-binding factor (CTCF), an insulator protein with 11 zinc fingers, is enriched at the boundaries of topologically associated domains (TADs) in eukaryotic genomes. In this study, we isolated and analyzed the cDNAs encoding HpCTCF, the CTCF homolog in the sea urchin Hemicentrotus pulcherrimus, to investigate its expression patterns and functions during the early development of sea urchin. HpCTCF contains nine zinc fingers corresponding to fingers 2-10 of the vertebrate CTCF. Expression pattern analysis revealed that HpCTCF mRNA was detected at all developmental stages and in the entire embryo. Upon expressing the HpCTCF-GFP fusion protein in early embryos, we observed its uniform distribution within interphase nuclei. However, during mitosis, it disappeared from the chromosomes and subsequently reassembled on the chromosome during telophase. Moreover, the morpholino-mediated knockdown of HpCTCF resulted in mitotic arrest during the morula to blastula stage. Most of the arrested chromosomes were not phospholylated at serine 10 of histone H3, indicating that mitosis was arrested at the telophase by HpCTCF depletion. Furthermore, impaired sister chromatid segregation was observed using time-lapse imaging of HpCTCF-knockdown embryos. Thus, HpCTCF is essential for mitotic progression during the early development of sea urchins, especially during the telophase-to-interphase transition. However, the normal development of pluteus larvae in CRISPR-mediated HpCTCF-knockout embryos suggests that disruption of zygotic HpCTCF expression has little effect on embryonic and larval development.

Does inflammatory dental disease affect the development of medication-related osteonecrosis of the jaw in patients using high-dose bone-modifying agents?

OBJECTIVES: High-dose bone-modifying agents (BMAs), such as bisphosphonates and denosumab, are essential for the treatment of cancer patients with bone metastases. The incidence of medication-related osteonecrosis of the jaw (MRONJ) is increasing. Inflammatory dental diseases could lead to MRONJ, and hence, they should be managed appropriately. Tooth extractions are commonly advised to prevent dental inflammation; however, the accurate indications for tooth extractions before starting BMA therapy have not been established. Hence, we assessed teeth with inflammatory dental diseases to identify indicators for prophylactic extraction before starting BMA therapy. MATERIALS AND METHODS: We included 745 teeth with inflammatory dental diseases of 212 cancer patients on high-dose BMA therapy. We assessed the relationship between inflammatory dental disease and risk of MRONJ development. Multivariate Cox regression analysis was used for statistical analysis. The cumulative occurrence rate of MRONJ was calculated using the Kaplan-Meier method. RESULTS: MRONJ occurred in 43 of 745 teeth. Teeth characteristics significantly correlated with MRONJ occurrence were mandible (p = 0.009), molar region (p = 0.005), radiopaque changes in bone surrounding the root on orthopantograms obtained at patients' first visits (p < 0.001), and tooth extractions after starting BMA therapy (p < 0.001). CONCLUSIONS: Radiopaque changes in bone surrounding the root are an important radiographic finding that indicates the need for prophylactic tooth extractions before starting BMA therapy. CLINICAL RELEVANCE: Our results suggest that the prophylactic extraction of teeth with radiopaque changes in bone surrounding the root before starting BMA therapy could prevent the onset of MRONJ.

Relationships of survival time, productivity and cause of death with telomere lengths of cows produced by somatic cell nuclear transfer.

The reproductive ability, milk-producing capacity, survival time and relationships of these parameters with telomere length were investigated in 4 groups of cows produced by somatic cell nuclear transfer (SCNT). Each group was produced using the same donor cells (6 Holstein (1H), 3 Holstein (2H), 4 Jersey (1J) and 5 Japanese Black (1B) cows). As controls, 47 Holstein cows produced by artificial insemination were used. The SCNT cows were artificially inseminated, and multiple deliveries were performed after successive rounds of breeding and conception. No correlation was observed between the telomere length and survival time in the SCNT cows. Causes of death of SCNT cows included accidents, accident-associated infections, inappropriate management, acute mastitis and hypocalcemia. The lifetime productivity of SCNT cows was superior to those of the controls and cell donor cows. All SCNT beef cows with a relatively light burden of lactation remained alive and showed significantly prolonged survival time compared with the cows in the SCNT dairy breeds. These results suggest that the lifetime productivity of SCNT cows was favorable, and their survival time was more strongly influenced by environmental burdens, such as pregnancy, delivery, lactation and feeding management, than by the telomere length.

Effectiveness of a real-time radiotelemetric pedometer for estrus detection and insemination in Japanese Black cows.

The objective of this study was to investigate the efficiency of estrus detection and determination of the time of ovulation in Japanese Black cows by a real-time radiotelemetric pedometer. A herd of Japanese Black cows was housed in a loose-housing barn. This pedometer system and a pressure-sensing radiotelemetric device, which detects standing events, were concurrently compared in regard to their availability for detection of estrus events. Pedometer estrus and standing events were observed for all cows (n=20), and the duration of increased walking activity was 15.8+/-0.9 h, which was longer (P<0.0001) than the duration of standing events (9.0+/-1.3 h). Ovulation was observed 30.2+/-0.6 h after the onset of pedometer estrus and 29.0+/-0.6 h after the first standing event. There was a high correlation (r=0.89, P<0.0001) between the intervals from the onset of pedometer estrus and onset of standing event to ovulation. The animals of the pedometric group (n=20) were inseminated 10 to 18 h after the onset of pedometer estrus and had a higher conception rate (90.0%, P<0.05) than those inseminated according to the a.m. /p.m. method (58.4%, n=24). In conclusion, the pedometer system is an excellent tool for precise estrus detection and insemination at the appropriate time, which ensure a high pregnancy rate in Japanese Black cows.