CRISPR/Cas9 protocols for disrupting gene function in the non-vertebrate chordate Ciona.

The evolutionary origins of chordates and their diversification into the three major subphyla of tunicates, vertebrates, and cephalochordates pose myriad questions about the genetic and developmental mechanisms underlying this radiation. Studies in non-vertebrate chordates have refined our model of what the ancestral chordate may have looked like, and have revealed the pre-vertebrate origins of key cellular and developmental traits. Work in the major tunicate laboratory model Ciona has benefitted greatly from the emergence of CRISPR/Cas9 techniques for targeted gene disruption. Here we review some of the important findings made possible by CRISPR in Ciona, and present our latest protocols and recommended practices for plasmid-based, tissue-specific CRISPR/Cas9-mediated mutagenesis.

Postoperative evaluation of the knee.

New developments and improvements in ligamentous and meniscal surgery and cartilage repair procedures have led to an increased incidence ot these procedures being performed. Subsequently, there has been a corresponding increase in postoperative imaging studies. and it is imperative for radiologists to be comfortable with the normal imaging appearance of these procedures and associated complications.