Comparative rna-seq analysis of region-specific miRNA expression in the epididymis of cattleyak.

The epididymis is the site of post-testicular sperm maturation, which constitutes the acquisition of sperm motility and the ability to recognize and fertilize oocytes. The role of miRNA in male reproductive system, including the control of different steps leading to proper fertilization such as gametogenesis, sperm maturation and maintenance of male fertility where the deletion of Dicer in mouse germ cells led to infertility, has been demonstrated. The identification of miRNA expression in a region-specific manner will therefore provide valuable insight into the functional differences between the regions of the epididymis. In this study, we employed RNA-seq technology to explore the expression pattern of miRNAs and establish some miRNAs of significant interest with regard to epididymal sperm maturation in the CY epididymis. We identified a total of 431 DE known miRNAs; 119, 185 and 127 DE miRNAs were detected for caput versus corpus, corpus versus cauda and caput versus cauda region pairs, respectively. Our results demonstrate region-specific miRNA expression in the CY epididymis. The GO and KEGG enrichment for the predicted target genes indicated the functional values of miRNAs. Furthermore, we observed that the expression of miR-200a was downregulated in the caput, compared with cauda. Since the family of miR-200 has previously been suggested to contribute to the distinct physiological function of sperm maturation in epididymis of adult rat, we speculate that the downregulation of miR-200a in CY caput epididymis may play an important role of sperm maturation in the epididymis of CY. Therefore, our findings may not only increase our understanding of the molecular mechanisms regulated by the miRNA functions in region-specific miRNA expression in the CY epididymis, it could provide a valuable information to understand the mechanism of male infertility of CY.

Spectral Mesh Segmentation via l0 Gradient Minimization.

Mesh segmentation is a process of partitioning a mesh model into meaningful parts - a fundamental problem in various disciplines. This paper introduces a novel mesh segmentation method inspired by sparsity pursuit. Based on the local geometric and topological information of a given mesh, we build a Laplacian matrix whose Fiedler vector is used to characterize the uniformity among elements of the same segment. By analyzing the Fiedler vector, we reformulate the mesh segmentation problem as a l0 gradient minimization problem. To solve this problem efficiently, we adopt a coarse-to-fine strategy. A fast heuristic algorithm is first devised to find a rational coarse segmentation, and then an optimization algorithm based on the alternating direction method of multiplier (ADMM) is proposed to refine the segment boundaries within their local regions. To extract the inherent hierarchical structure of the given mesh, our method performs segmentation in a recursive way. Experimental results demonstrate that the presented method outperforms the state-of-the-art segmentation methods when evaluated on the Princeton Segmentation Benchmark, the LIFL/LIRIS Segmentation Benchmark and a number of other complex meshes.