The T. parvula genome assembly has now entered its "version 2" phase. The sequences for versions 1 and 2 as well as the predicted gene models are now available here. In addition, a BLAST tool linked to these is available here to compare these to other sequences.
A second species, Thellungiella salsuginea (salt cress; synonymous to Thellungiella halophila, Al-Shebaz et al., 1999) has also been sequenced although the assembly has not yet been published. Analysis of ESTs, however, revealed 90-95% nucleotide identity in transcripts for well-known housekeeping genes, although sequences with lower identity were also found suggesting the presence of paralogous genes (Inan et al., 2004).
Despite their close genetic relationship, the Thellungiella species differ considerably from Arabidopsis in their physiology. In particular, the Thellungiellas tolerates extreme cold, drought and salinity. Introduced into the laboratory by Ziyi Cao, Hui Zhang and their colleagues (Shandong Normal University, China), T. salsuginea's use for salinity research has been promoted by Jian-Kang Zhu and colleagues in the US (Zhu, 2001; Bressan et al. 2001; Amtmann et al., 2005). Since then several groups worldwide have started to study its physiology, metabolism and molecular genetics.
As of 2006, several ecotypes had been collected from Central Asia and North America. Global insertion mutagenesis was underway. BAC libraries, ESTs, and full-length cDNA libraries were available. Several multi-disciplinary, multi-institutional groups have begun to focus on the distinctive mechanisms that cause the extreme stress tolerance of this species. The evolutionary position of the genus between Brassica and Arabidopsis has attracted attention and phylogenetic studies.
