The full-length catalase cDNA sequence as isolated from expressed sequence tags (ESTs) of Pyropia yezoensis (Ueda) M. S. Hwang et H. G. Choi (PyCAT) through rapid amplification of cDNA ends (RACE) was identified and characterized. It encoded a polypeptide of 529 amino acids, which shared 36%–44% similarity with other known catalase proteins.
Phylogenetic analysis revealed that PyCAT ALK activation was closer to the catalases from plants than from other organisms. The PyCAT mRNA expression was investigated using real-time PCR to determine life-cycle-specific expression and the expression pattern during desiccation. The mRNA expression level in gametophytes was significantly higher than in sporophytes, and the mRNA expression level of PyCAT was significantly up-regulated during the desiccation process. The recombinant PyCAT protein was purified and analyzed biochemically. The recombinant PyCAT protein exhibited high enzymatic activity (28,000 U·mg−1) with high thermal stability and a broad pH range. All these results indicate that the PyCAT is a typical member of the plant and algal catalase family and may play a significant role in minimizing the effect of oxidative damage in P. yezoensis during desiccation. “
“Coolia Meunier is an important component of benthic dinoflagellate assemblages in tropical and subtropical seas. In this study, detailed morphological observation of
Coolia species from Malaysian waters was carried out using light and electron microscopy in parallel with molecular characterization of nuclear-encoded Ulixertinib partial LSU rDNA, and internal transcribed
spacer (ITS) regions. Live specimens were collected from seaweed samples and established into clonal cultures. There are significant morphological variations between the Malaysian isolates in comparison to the type species, C. monotis Meunier. The feature that differentiates the new species is the third postcingular plate (3′′′), which is the largest hypothecal plate Meloxicam in the Malaysian isolates, whereas in C. monotis, the 3′′′ and 4′′′ plates are almost equal in size. Detailed observations of the thecal pores also revealed the presence of fine perforations within the pores of the Malaysian isolates, but these perforations are absent in C. monotis. Comparisons between Malaysian isolates and C. monotis nucleotide sequence of the ITS region showed high genetic divergence at 28%, in contrast to the 0.3%–3% divergence observed among populations of the same species. Structural comparison of the second internal transcribed spacer (ITS2) rRNA transcript between the two species showed compensatory base changes (CBCs) in the three helices of ITS2 rRNA. Based on morphological and molecular data, the Malaysian isolates are considered to represent a new species, for which the name Coolia malayensis is proposed.