D-阿拉伯糖(10323-20-3)(≥98%)

Nature 子刊：确定男性避孕关键基因，敲除后 98% 精子形态异常

的是，缺乏该基因也会引起严重的不育症，导致一种称为少精症的病症。这是人类男性不育症中最常见的情况，显示产生的精子数量减少、活动速度减慢和精子形状扭曲，因此精子无法与卵子融合。 在这项研究中，在雄性小鼠中敲除基因 Arrdc5 后，其产生的精子数量减少了 28%，移动速度比正常小鼠慢了 2.8 倍，大约 98% 的精子头部和中段异常。该结果表明，该基因编码的蛋白质是正常精子生产所必需的。 图片来源：Nature Communications   该研究团队表示，他们已经申请了一项临时专利，用于开发

Synthesis and Properties of 7‐Substituted 7‐Deazapurine (Pyrrolo[2,3‐d]pyrimidine) 2′‐Deoxyribonucleosides

7?deazapurine (pyrrolo[2,3?d ]pyrimidine) 2??deoxyribonucleosides are synthesized by stereoselective nucleobase anion glycosylation. The introduction of a halogen at C7 is performed regioselectively either on the nucleobase or on the nucleoside. The pK a values

PCR Site-Directed Mutagenesis Using Pyrococcus sp GB-D Polymerase Coupled to a Rapid Screening Procedure: Application to a -Glucanase Gene

(3 ,4 ). In the present protocol, we describe an improvement on the efficiency of site-directed mutagenesis by PCR using the Pyrococcus species GB-D polymerase instead of the commonly used Thermus aquatiqus (Taq) polymerase. Taq polymerase lacks a 3′→5′ proofreading