Identification of SRY‐box 30 as an age‐related essential gatekeeper for male germ‐cell meiosis and differentiation

Although important factors governing the meiosis have been reported in the embryonic ovary, meiosis in postnatal testis remains poorly understood. Herein, we first report that SRY‐box 30 (Sox30) is an age‐related and essential regulator of meiosis in the postnatal testis. Sox30‐null mice exhibited uniquely impaired testis, presenting the abnormal arrest of germ‐cell differentiation and irregular Leydig cell proliferation. In aged Sox30‐null mice, the observed testicular impairments were more severe. Furthermore, the germ‐cell arrest occurred at the stage of meiotic zygotene spermatocytes, which is strongly associated with critical regulators of meiosis (such as Cyp26b1, Stra8 and Rec8) and sex differentiation (such as Rspo1, Foxl2, Sox9, Wnt4 and Ctnnb1). Mechanistically, Sox30 can activate Stra8 and Rec8, and inhibit Cyp26b1 and Ctnnb1 by direct binding to their promoters. A different Sox30 domain required for regulating the activity of these gene promoters, providing a “fail‐safe” mechanism for Sox30 to facilitate germ‐cell differentiation. Indeed, retinoic acid levels were reduced owing to increased degradation following the elevation of Cyp26b1 in Sox30‐null testes. Re‐expression of Sox30 in Sox30‐null mice successfully restored germ‐cell meiosis, differentiation and Leydig cell proliferation. Moreover, the restoration of actual fertility appeared to improve over time. Consistently, Rec8 and Stra8 were reactivated, and Cyp26b1 and Ctnnb1 were reinhibited in the restored testes. In summary, Sox30 is necessary, sufficient and age‐associated for germ‐cell meiosis and differentiation in testes by direct regulating critical regulators. This study advances our understanding of the regulation of germ‐cell meiosis and differentiation in the postnatal testis.     

云雾山自然保护区优势植物种群分布格局的分形特征

对宁夏云雾山草原自然保护区植物种群分布格局的分形计盒维数进行了研究。结果表明：本氏针茅、铁杆蒿和百里香是该区的优势种。3种优势种的计盒维数在1．7左右，表明它们具有较大的空间占据能力。但是它们的计盒维数最大值出现的时间不同，本氏针茅、百里香计盒维数最大值出现存封育20a的样地中，铁杆蒿出现在封育25a的样地中。     

Ribonucleoprotein multimers and their functions

Ribonucleoproteins (RNPs) play key roles in many cellular processes and often function as RNP enzymes. Similar to proteins, some of these RNPs exist and function as multimers, either momomeric or heteromeric. While in some cases the mechanistic function of multimerization is well understood, the functional consequences of multimerization of other RNPs remain enigmatic. In this review we will discuss the function and organization of small RNPs that exist as stable multimers, including RNPs catalyzing RNA chemical modifications, telomerase RNP, and RNPs involved in pre-mRNA splicing.     

Association of single nucleotide polymorphisms in the microRNA miR‐1596 locus with residual feed intake in chickens

MicroRNAs are an abundant class of small non‐coding RNAs that regulate gene expression. Genetic variations in microRNA sequences may be associated with phenotype differences by influencing the expression of microRNAs and/or their targets. This study identified two single nucleotide polymorphisms (SNPs) in the genomic region of the microRNA miR‐1596 locus of chicken. Of the two SNPs, one was 95 bp upstream of miR‐1596 (g.5678784A>T) and the other was in the middle of the sequence producing the mature microRNA gga‐miR‐1596‐3p (g.5678944A>G). Genotypic distribution of the two SNPs had large differences among 12 chicken breeds (lines), especially between the fast‐growing commercial lines and the slow‐growing Chinese indigenous breeds for the g.5678784A>T SNP. Only the g.5678784A>T SNP was significantly associated with residual feed intake (RFI) in the F₂ population derived from a fast‐growing and a slow‐growing broiler as well as in the pure Huiyang bearded chicken. The birds with the AA genotype of the g.5678784A>T SNP had lower RFI and higher expression of the mature gga‐miR‐1596‐3p microRNA of miR‐1596 than did those with the other genotypes of the same SNP. We also found that the expression of the mature gga‐miR‐1596‐3p microRNA of miR‐1596 was significantly associated with RFI. These findings suggest that miR‐1596 can become a candidate gene related to RFI, and its genetic variation may contribute to changes in RFI by altering expression levels of the mature gga‐miR‐1596‐3p microRNA in chicken.     

A Theft-Resistant Adjustable Security Box for Digital Cameras

Abstract: Remote camera traps are becoming an increasingly popular, affordable, and valuable tool for wildlife research. However, theft and vandalism of these camera systems can result in substantial financial loss and loss of valuable data. We developed an adjustable steel camera security box to protect our Cuddeback® (Non Typical, Inc., Park Falls, WI) digital scouting cameras. Our cameras were deployed for 160 days and experienced no theft or vandalism during that time. Our armored camera box successfully protected our equipment and data, can be sized to accommodate any brand of camera, and can be used in a variety of field situations.