No abstract

Animal oocytes undergo a highly conserved developmental arrest in prophase of meiosis I. Often this marks a period of rapid growth for the oocyte and is necessary to coordinate meiotic progression with the developmental events of oogenesis. In Drosophila, the oocyte develops within a 16-cell germline cyst. Throughout much of oogenesis, the oocyte remains in prophase of meiosis I. By contrast, its 15 mitotic sisters enter the endocycle and become polyploid in preparation for their role as nurse cells. How germline cysts establish and maintain these two independent cell cycles is unknown. We demonstrate a role for the p21 CIP /p27 Kip1 /p57 Kip2 -like cyclin-dependent kinase inhibitor (cki) dacapo in the maintenance of the meiotic cycle in Drosophila oocytes. Our data indicate that it is through the differential regulation of the cki Dacapo that two modes of cell-cycle regulation are independently maintained within the common cytoplasm of ovarian cysts.

The suspension of elective operations in March 2020 to prepare for the COVID-19 surge posed significant challenges to resident education. To mitigate the potential negative effects of COVID-19 on surgical education, it is important to quantify how the pandemic influenced resident operative volume.OBJECTIVE To examine the association of the pandemic with general surgical residents' operative experience by postgraduate year (PGY) and case type and to evaluate if certain institutional characteristics were associated with a greater decline in surgical volume.

No abstract