Isolation and Identification of Acholeplasma sp. from the Mud Crab, Scylla serrata.

For the first time, a mollicute-like organism (MLO) was cultured from moribund mud crabs (Scylla serrata) during an outbreak of clearwater disease in Zhejiang Province, China. The MLO displayed a fried-egg colony morphology in culture, did not possess a cell wall, and was not retained by 0.45 µm and 0.2 µm filters. It was able to ferment glucose, sucrose, lactose, and maltose, but it did not utilize arginine and urea. The MLO grew in the absence of bovine serum and was not susceptible to digitonin. Sequence analysis of the 16S rRNA gene revealed that this MLO had 99% identity with Acholeplasma laidlawii PG-8A, which indicates that the organism isolated from mud crabs is a member of the genus Acholeplasma.

[The progress on T-DNA integration research].

The T-DNA integration is a critical step of the steady inheritance for foreign genes during the Agrobacterium tumefaciens-mediated transformation. There are many factors that influence the integration, including virulence proteins, host factors and so on. The article reviews the recent progress in these aspects, and also expatiates on the integration of T-DNA in host genome and distribution in the chromosomal level and the integration models.