The E3 ubiquitin ligase MIB-1 is necessary to form the nuclear halo in C. elegans sperm

Unlike the classical nuclear envelope with two membranes found in other eukaryotic cells, most nematode sperm nuclei are not encapsulated by membranes. Instead, they are surrounded by a nuclear halo of unknown composition. How the halo is formed and regulated is unknown. We used forward genetics to identify molecular lesions behind three classical fer (fertilization defective) mutations that disrupt the ultrastructure of the C. elegans sperm nuclear halo. We found fer-2 and fer-4 alleles to be nonsense mutations in mib-1. fer-3 was caused by a nonsense mutation in eri-3. GFP::MIB-1 was expressed in the germline during early spermatogenesis, but not in mature sperm. mib-1 encodes a conserved E3 ubiquitin ligase homologous to vertebrate Mib1 and Mib2, which function in Notch signaling. However, C. elegans mib-1 has no Notch-related phenotypes. Thus, mib-1 has been co-opted to regulate the formation of the nuclear halo during nematode spermatogenesis.

The Use of Platelet-Rich Plasma for Storage of Surplus Harvested Skin Grafts

Background: There is a need for improved methods and storage media to sustain the tissue viability of autologous skin grafts. Objective: To compare histological changes in human skin grafts stored in platelet-rich plasma (PRP) with those of grafts stored in saline. Methods: Eight circular, 3-mm full-thickness skin graft samples were harvested from the abdominal skin of each of 5 patients scheduled to undergo an abdominoplasty procedure. Four of these graft samples were stored in saline, and the other 4 were stored in saline mixed with PRP prepared from the patient’s own venous blood. Histological assessment of the microscopic appearance of the samples was performed on days 5, 8, 11, and 14. The integrity of the epidermal–dermal junction, number of keratinocytes with perinuclear halos, collagen organization, and number of fibroblasts per field were assessed. The cellular apoptosis rate was also measured on these same days. Results: On day 5, significant differences were observed microscopically between the PRP- and saline-stored grafts ( P < .05). The grafts preserved in saline exhibited early marked cellular and nuclear swelling with pleomorphism, as well as early nuclear halo formation. The cell viability rate of the PRP group was significantly higher than that of the saline-stored group on day 8 ( P < .05). Conclusion: Platelet-rich plasma and its inherent growth factors supported longer graft survival; however, its effect lasted only until day 8. Platelet-rich plasma may be beneficial if grafts need to be stored for delayed application(s).

Puzzle of the folding potential on the nuclear halo reactions

Folding potentials of the elastic scattering drip-line nuclei at various incident energies is one method to study nuclear matter density distributions and nuclear radii. The nuclei with density distributions consisting of a bulk (core) and an outer layer (halo), dilute and spatially extended are called the halo nuclei caused for the weak particle binding. Several halo nuclei are studied and many potential candidates are identified. All the cross-sections of the elastic scattering for the drip-line nuclei 11 Be and 6 He , are calculated to understand the exotic properties of these nuclei starting from its structure, extended radius, nuclear size till the large total reaction cross-sections for these nuclei when it interact with a stable target 12 C .