Ovular development and morphology of the outer integument of Magnolia grandiflora (Magnoliaceae)

Ovular development of Magnolia grandiflora was examined to determine the morphology of the outer integument. At the time the ovular primordium begins incurving, the outer integument is initiated subdermally, and later the inner integument arises from the dermal layer. Whereas the inner integument is annular, the outer integument is formed as a semiannular rim interrupted on the concave side of the funiculus. Later the outer integument becomes a hood-shaped envelope. The obturator is formed as a transversely elongate outgrowth on the concave side of the funiculus and intervenes in the gap of the outer integument. During further development the inner integument produces several distal lobes, and the outer integument becomes bilobed. The exostome is a transverse slit with a middle notch, formed by the outer integument and the obturator. Presumed wide occurrence of the hood-shaped outer integument in primitive families suggests that it is a primitive state. The outer integument is compared with the ovuliferous sporophylls of the glossopterid and caytonialean seed ferns.     

Development of a novel purification method for AAV vectors using tangential flow filtration

Adeno-associated virus (AAV) vector can efficiently transduce therapeutic genes in various tissue types with less side effects; however, owing to complex multistep processes during manufacture, there have been surges in the pricing of recently approved AAV vector-based gene therapy products. This study aimed to develop a simple and efficient method for high-quality purification of AAV vector via tangential flow filtration (TFF), which is commonly used for concentration and diafiltration of solutions during AAV vector purification. We established a novel purification method using TFF and surfactants. Treatment with two classes of surfactants (anionic and zwitterionic) successfully inhibited the aggregation of residual proteins separated from the AAV vector in the crude product by TFF, obtaining a clearance of 99.5% residual proteins. Infectivity of the AAV vector purified using the new method was confirmed both in vitro and in vivo, and no remarkable inflammation or tissue damage was observed in mouse skeletal muscle after local administration. Overall, our proposed method could be used to establish a platform for the purification of AAV vector.