The species-specific exon activities calls for another look at the distinguishing characteristics of species. It also leads us to question the assumption that each species evolved from another, since there are distinct barriers for one species to transition to another. Since aberrant splicing has been linked to disease, it leads us to believe that the purpose of the organism's reproduction is not to produce new species, but to reproduce the old offspring with recombined DNA, exhibiting genetic diversity to protect against disease, but still being a member of a distinct species. (One short-coming here is, of course, that we don't know what the term "species" is. But the recombination of old components into new patterns within certain boundaries is definitely a common -- yet profound -- biological phenomenon).
When I read the sentence
"...[W]e have shown that humans and closely related mammalian species display widespread differences in exon usage and splicing patterns, suggesting an important role of species-specific splicing regulation in the acquisition of human-specific traits."I was dumbfounded. It's data, comma, interpretation. And the interpretation is a function of the evolutionary assumptions of those analyzing the data:
i = f(a)
interpretation = function of assumptions
Can you imagine what would happen if for one moment the "roof was lifted," and evolutionary biologists imagined life without evolution?
The sun would stream in, and the submissions to Nature and Science would be filled with amazingly diverse interpretations where once the theory of "evolution" kept out the light.
BIOENGINEERING SEMINAR SERIES
Thursday, October 1, 12:00 – 1:00 p.m.
2240 Digital Computer Lab (DCL)
Yi Xing, Ph.D.
Assistant Professor, Departments of Internal Medicine & Biomedical Engineering
University of Iowa
Alternative splicing is a major source of regulatory and functional diversity in higher eukaryotes. In humans, over 90% of multi-exon genes are alternatively spliced, and aberrant alternative splicing causes a broad range of diseases. We have developed new computational tools for global analysis of alternative splicing using array and sequencing based technologies. By combining these high-throughput approaches with detailed molecular investigations, we have shown that humans and closely related mammalian species display widespread differences in exon usage and splicing patterns, suggesting an important role of species-specific splicing regulation in the acquisition of human-specific traits. For example, contrary to the common belief that newly born exons in the genome are predominantly evolutionary intermediates without established functions, we found extensive creation of new exons with strong splicing activities or tissue-specific splicing patterns during primate and human evolution. These findings shed light on how evolutionary innovations in RNA processing expand the functional and regulatory repertoire of eukaryotic genomes.
Dr. Yi Xing is an assistant professor at the Departments of Internal Medicine and Biomedical Engineering of the University of Iowa. He received his B.S. in Molecular and Cellular Biology and B.E. in Computer Science and Technology in 2001 from the University of Science and Technology of China. He completed his Ph.D. training in Bioinformatics with Dr. Christopher Lee at the University of California, Los Angeles (2001-2006), and his postdoctoral training with Drs. Wing Hung Wong and Matthew Scott at the Stanford University (2006-2007). Dr. Xing has published extensively on genome-scale analysis of mammalian gene expression and RNA splicing. His group is currently combining genomic, bioinformatic, and molecular approaches to study variations of pre-mRNA processing within and between species. His research spans the areas of bioinformatics, genomics, evolutionary biology, and medical genetics.