Fatty acids are precursors of potent lipid signaling molecules. They are stored in membrane phospholipids and released by phospholipase A2 (PLA2). Lysophospholipid acyltransferases (ATs) oppose PLA2 by re-esterifying fatty acids into phospholipids, in a biochemical pathway known as the Lands Cycle. Drosophila Lands Cycle ATs oys and nes, as well as 7 predicted PLA2 genes, are expressed in the male reproductive tract. Oys and Nes are required for spermatid individualization. Individualization, which occurs after terminal differentiation, invests each spermatid in its own plasma membrane and removes the bulk of the cytoplasmic contents. We developed a quantitative assay to measure individualization defects. We demonstrate that individualization is sensitive to temperature and age but not to diet. Mutation of the cyclooxygenase Pxt, which metabolizes fatty acids to prostaglandins, also leads to individualization defects. In contrast, modulating phospholipid levels by mutation of the phosphatidylcholine lipase Swiss cheese (Sws) or the ethanolamine kinase Easily shocked (Eas) does not perturb individualization, nor does Sws overexpression. Our results suggest that fatty acid derived signals such as prostaglandins, whose abundance is regulated by the Lands Cycle, are important regulators of spermatogenesis.

Purpose To determine the diagnostic capability of peripapillary 3-dimensional (3D) retinal nerve fiber layer (RNFL) volume measurements from spectral domain optical coherence tomography (OCT) volume scans for open angle glaucoma (OAG). Design Assessment of diagnostic accuracy. Methods Setting Academic clinical setting. Study population 180 patients (113 OAG and 67 normal subjects). Observation procedures One eye per subject was included. Peripapillary 3D RNFL volumes were calculated for global, quadrant, and sector regions, using four different sized annuli. Peripapillary 2D RNFL thickness circle scans were also obtained. Main outcome measures Area under the receiver operating characteristic curve (AUROC) values, sensitivity, specificity, positive and negative predictive values, positive and negative likelihood ratios. Results Among all 2D and 3D RNFL parameters, best diagnostic capability was associated with inferior quadrant 3D RNFL volume of the smallest annulus (AUROC curve value 0.977). Otherwise, global 3D RNFL volume AUROC curve values were comparable to global 2D RNFL thickness AUROC curve values for all 4 annuli sizes (p values: 0.0593 to 0.6866). When comparing the 4 annuli sizes for global RNFL volume, the smallest annulus had the best AUROC curve values (p values: 0.0317 to 0.0380). The smallest sized annulus may have the best diagnostic potential partly due to having no areas excluded for being larger than the 6×6 mm square scanned region. Conclusion Peripapillary 3D RNFL volume showed excellent diagnostic performance for detecting glaucoma. Peripapillary 3D RNFL volume parameters have the same or better diagnostic capability compared to peripapillary 2D RNFL thickness measurements, although differences were not statistically significant.