Search

Macrophages can phagocytose sperm, especially damaged spermatozoa, in the female genital tract. The semenogelin I-derived peptide SgI-52 in seminal plasma exhibits seminal plasma motility inhibitor (SPMI) activity and can inhibit sperm motility. This raises the question of the role played by SPMIs in macrophage-mediated phagocytosis of sperm. We speculated that SgI-52 promotes sperm clearance by macrophages. Therefore, we investigated the phagocytosis of sperm in different states using this peptide.SgI-52 was fluorescently labeled, and its binding site for sperm was observed. The ability of macrophages to phagocytose sperm was observed using fluorescence confocal microscopy. Spermatozoa from different sources were co-cultured with SgI-52 in BWW medium for 4 and 22 h to compare the differences in their phagocytosis by macrophages. Sperm motility, induced acrosome reaction, mitochondrial membrane potential, and ATP content were examined after incubation with SgI-52.SgI-52 could bind to spermatozoa in different states, mainly to the tail, and then spread to the acrosome. This effect was more pronounced in demembranated spermatozoa. SgI-52 promoted phagocytosis of spermatozoa by macrophages, decreased the mitochondrial membrane potential, and increased the average ATP content of spermatozoa (P 0.05).We found for the first time that SgI-52 can bind to spermatozoa in different states and promote their phagocytosis by macrophages. Therefore, we speculate that SgI-52 is involved in the screening of sperm in the female reproductive tract and has potential value in improving assisted reproductive technology.

Folds and faults are the most common types of basic structures in geological formations. Marine controlled-source electromagnetic (CSEM) data are strongly affected by folds, faults and other complex irregular geological structures in subsea geo-environments because of their electrical anisotropy and the bathymetry generated by these types of structures. In this work, we investigate the effects of two typical geological structures, folds and faults, on marine CSEM responses by using an adaptive finite-element modeling approach. The adoption of unstructured tetrahedral grids in our code easily allows the inclusion of complex model geometries so that natural environments can be mapped into the model realistically. For the fold models, we investigate the impacts of anticlines, synclines and mixed anticline-syncline-type structures; numerical results indicate that both anticlines and synclines can produce considerable negative electromagnetic anomalies, which may be neutralized to a certain extent by the positive electromagnetic anomalies of a highly resistive target reservoir. The response curve of a syncline displays a “W” shape whose central part consisting of rising positive anomalies may be mistaken as the response of a highly resistive reservoir when interpreting CSEM data. Furthermore, the negative anomalies caused by the anticlines/synclines increase with the increasing inclination of their limbs. For the fault models, we investigate the effects of horsts and grabens on marine CSEM responses and results show that the responses of horsts/grabens can be large enough to mask the target reservoir's response. We conclude that folds and faults clearly have to be taken into account to avoid the misinterpretation of marine CSEM data.