Recent advances in the study of the CRISPR/Cas9 system have provided a precise and versatile approach for genome editing in various species. However, the applicability and efficiency of this method in large animal models, such as the goat, have not been extensively studied. Here, by co-injection of one-cell stage embryos with Cas9 mRNA and sgRNAs targeting two functional genes (MSTN and FGF5), we successfully produced gene-modified goats with either one or both genes disrupted. The targeting efficiency of MSTN and FGF5 in cultured primary fibroblasts was as high as 60%, while the efficiency of disrupting MSTN and FGF5 in 98 tested animals was 15% and 21% respectively, and 10% for double gene modifications. The on- and off-target mutations of the target genes in fibroblasts, as well as in somatic tissues and testis of founder and dead animals, were carefully analyzed. The results showed that simultaneous editing of several sites was achieved in large animals, demonstrating that the CRISPR/Cas9 system has the potential to become a robust and efficient gene engineering tool in farm animals, and therefore will be critically important and applicable for breeding.

Perovskite solar cells as a hot research topic show the necessity of controlling the interface. In this work, an insulating alkyl chain layer is self-assembled at the perovskite/hole transport material interface, which successfully exhibits a dual function: blocking electron recombination and resisting moisture at the same time. Improved solar energy conversion efficiency and stability of the device are both achieved.

Depositing pinhole-free perovskite films is of vital importance for achieving high performance perovskite solar cells, especially in a planar heterojunction device. Here, perovskite films with coverage approaching 100% and with highly oriented crystal domains were obtained by carefully controlling the annealing temperature and duration. Perovskite solar cells with an average efficiency of 12% and a maximum efficiency of 15.17% were achieved in a planar heterojunction structure. Comprehensive characterization and analysis showed that appropriate annealing temperature and duration allowed the perovskite crystals to grow slowly, resulting in highly oriented crystal domains without any internal voids or pinholes. The anisotropic transport properties of perovskite crystals ensure efficient electron and hole transport to their corresponding electrodes.

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A previous whole-genome association analysis identified lysine demethylase 6A (KDM6A), which encodes a type of histone demethylase, as a candidate gene associated to goat fecundity. KDM6A gene knockout mouse disrupts gametophyte development, suggesting that it has a critical role in reproduction. In this study, goat KDM6A mRNA expression profiles were determined, insertion/deletion (indel) variants in the gene identified, indel variants effect on KDM6A gene expression assessed, and their association with first-born litter size analyzed in 2326 healthy female Shaanbei white cashmere goats. KDM6A mRNA was expressed in all tissues tested (heart, liver, spleen, lung, kidney, muscle, brain, skin and testis); the expression levels in testes at different developmental stages [1-week-old (wk), 2, 3 wk, 1-month-old (mo), 1.5 and 2 mo] indicated a potential association with the mitosis-to-meiosis transition, implying that KDM6A may have an essential role in goat fertility. Meanwhile, two novel intronic indels of 16 bp and 5 bp were identified. Statistical analysis revealed that only the 16 bp indel was associated with first-born litter size (P < 0.01), and the average first-born litter size of individuals with an insertion/insertion genotype higher than that of those with the deletion/deletion genotype (P < 0.05). There was also a significant difference in genotype distributions of the 16 bp indel between mothers of single-lamb and multi-lamb litters in the studied goat population (P = 0.001). Consistently, the 16 bp indel also had a significant effect on KDM6A gene expression. Additionally, there was no significant linkage disequilibrium (LD) between these two indel loci, consistent with the association analysis results. Together, these findings suggest that the 16 bp indel in KDM6A may be useful for marker-assisted selection (MAS) of goats.

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For fixed generalized reflection matrix P, i.e. P T = P, P 2 = I, then matrix X is said to be generalized bisymmetric, if X = X T = PX P. In this paper, an iterative method is constructed to find the generalized bisymmetric solutions of the matrix equation A 1 X 1 B 1 + A 2 X 2 B 2 + · · · + A l X l B l = C where [X 1 , X 2 , · · · , X l ] is real matrices group. By this iterative method, the solvability of the matrix equation can be judged automatically. When the matrix equation is consistent, for any initial generalized bisymmetric matrix group X (0) 1 , X (0) 2 , · · · , X (0) l , a generalized bisymmetric solution group can be obtained within finite iteration steps in the absence of roundoff errors, and the least norm generalized bisymmetric solution group can be obtained by choosing a special kind of initial generalized bisymmetric matrix group. In addition, the optimal approximation generalized bisymmetric solution group to a given generalized bisymmetric matrix group X 1 , X 2 , · · · , X l in Frobenius norm can be obtained by finding the least norm generalized bisymmetric solution group of the new matrix equation A 1 X 1 B 1 + A 2 X 2 B 2 + · · · + A l X l B l = C, where C = C − A 1 X 1 B 1 − A 2 X 2 B 2 − · · · − A l X l B l . Given numerical examples show that the algorithm is efficient.

Let K[x 1 , . . . , x n ] be the polynomial ring over a field K in variables x 1 , . . . , x n . Let Θ = (θ 1 , . . . , θ n ) be a list of n homogeneous polynomials of same degree in K[x 1 , . . . , x n ]. Polynomial composition by Θ is the operation of replacing x i of a polynomial by θ i . The main question of this paper is: When does homogeneous polynomial composition commute with homogeneous Gröbner bases computation under the same term ordering? We give a complete answer: for every homogeneous Gröbner basis G, G • Θ is a homogeneous Gröbner basis under the same term ordering if and only if the composition by Θ is homogeneously compatible with the term ordering and Θ is a 'permuted powering.'