Volvox carteri is an excellent model for investigating the evolution of multicellularity and cell differentiation, and the rate of future progress with this system will depend on improved molecular genetic tools. Several selectable markers for nuclear transformation of V. carteri have been developed, including the nitrate reductase (nitA) gene, but it would be useful to have additional markers to multiplex transgenes in this species. To further facilitate molecular genetic analyses of V. carteri, we developed two new selectable markers that provide rapid, easily selected, and stable resistance to the antibiotics hygromycin and blasticidin. We generated constructs with Volvox-specific regulatory sequences and codon-optimized hygromycin (VcHyg) and blasticidin (VcBlast) resistance genes from Coccidioides posadasii and Bacillus cereus, respectively. With these constructs, transformants were obtained via biolistic bombardment at rates of 0.5–13 per million target cells bombarded. Antibiotic-resistant survivors were readily isolated 7 days post bombardment. VcHyg and VcBlast transgenes and transcripts were detected in transformants. Co-transformation rates using the VcHyg or VcBlast markers with unselected genes were comparable to those obtained with nitA. These results indicate that the pVcHyg and pVcBlast plasmids are highly efficient and convenient for transforming and co-transforming a broad range of V. carteri strains.

Volvox Carteri是研究多细胞性和细胞分化演变的绝佳模型，该系统未来的进展速度将取决于改进的分子遗传学工具。对于核转化几个选择标记V. carteri已经制定，包括硝酸还原酶（NITA）的基因，但它是有额外的标记在该物种多重转基因有用。为了进一步促进卡氏弧菌的分子遗传学分析，我们开发了两种新的选择标记，它们对抗生素潮霉素和杀稻瘟素具有快速，容易选择和稳定的抵抗力。我们生成了具有Volvox特异性调控序列和密码子优化的潮霉素（VcHyg）和稻瘟菌素（VcBlast）抗性基因的构建体，分别来自球孢子虫和蜡状芽孢杆菌。使用这些构建体，通过生物弹轰击以每百万个靶细胞被轰击0.5-13个的速率获得了转化子。轰炸后7天可轻易分离出具有抗生素抗性的幸存者。在转化体中检测到VcHyg和VcBlast转基因和转录本。使用VcHyg或VcBlast标记与未选择的基因的共转化率与nitA获得的转化率相当。这些结果表明，所述pVcHyg和pVcBlast质粒是高效和方便的用于转化和共转化广泛的V. carteri菌株。