Coevolutionary insights between promoters and transcription factors in the plant and animal kingdoms.

The divergence and continuous evolution of plants and animals contribute to ecological diversity. Promoters and transcription factors (TFs) are key determinants of gene regulation and transcription throughout life. However, the evolutionary trajectories and relationships of promoters and TFs are still poorly understood. Here, we conducted extensive analysis of large-scale multi-omics sequences in 420 animal species and 223 plant species spanning nearly a billion years of evolutionary history. Results showed that promoter GC-content and TF isoelectric points, as features/signatures that accompany long biological evolution, exhibited increasing growth in animal cells but a decreasing trend in plant cells. Furthermore, the evolutionary trajectories of promoter and TF signatures in the animal kingdom provided further evidence that Mammalia as well as Aves evolved directly from the ancestor Reptilia. The strong correlation between promoter and TF signatures indicates that promoters and TFs formed antagonistic coevolution in the animal kingdom, but mutualistic coevolution in the plant kingdom. The distinct coevolutionary patterns potentially drive the plant-animal divergence，divergent evolution and ecological diversity.

Effects of intron retention on properties of ß-glucosidase in Aspergillus niger.

Intron retention, one of the major types of alternative splicing in plants and animals, has also been reported existing in filamentous fungi's glycoside hydrolases. In this study, an intron-retained ß-glucosidase gene transcript (bgl1B) from A. niger B2 strain was obtained. Compared with the normally spliced transcript bgl1A, bgl1B had an extra 51bp insertion, which was confirmed to be the sixth (the last) intron of this ß-glucosidase gene. The bgl1A and bgl1B were expressed in Pichia pastoris and the purified enzymes were used to compare their catalytic properties. The results showed that the intron retention didn't impair the catalytic function. Instead, the intron-retained enzyme BGL1B had a better thermostability with a higher optimal temperature and a longer half-life under 50 °C. Also it exhibited a little higher kcat for 4-nitrophenyl-ß-d-glucopyranoside (PNPG) and a noticeable higher hydrolysis efficiency towards geniposide. This work suggested that the ß-glucosidase gene in A. niger most likely underwent an alternative splicing presented as intron retention type, and intron retention might be a source of enzyme diversity in fungi.