Past Projects
- Evolution of Novel Gene Functions
- Bioinformatics
- Selective Sweep
- C-Value Paradox
- Transposable Element Mariner
- Structure and Sequence of the Drosophila Genome
- Genome Structure and Evolution in D. virilis
- Cosuppression of Transposable Elements
- Molecular Evolution in Enteric Bacteria
- Gregor Mendel
- Active Projects
Evolution of Novel Gene Functions
Sdic is a new gene that evolved recently in the lineage of Drosophila melanogaster. It was formed from a duplication and fusion of the gene AnnX, which encodes annexin X, and Cdic, which encodes the intermediate polypeptide chain of the cytoplasmic dynein. The fusion joins AnnX exon 4 with Cdic intron 3, which brings together three putative promoter elements for testes-specific expression of Sdic. Translation of Sdic is initiated within the sequence derived from Cdic intron 3, continuing through a 10 base pair insertion that creates a new splice donor site that enables the new coding sequence derived from intron 3 to be joined with the coding sequence of Cdic exon 4. A novel protein is created lacking 100 residues at the amino end that contain sequence motifs essential for the function of cytoplasmic dynein intermediate chains. Instead, the amino end is a hydrophobic region of 16 residues that resembles the amino end of axonemal dynein intermediate chains from other organisms. The downstream portion of Sdic features large deletions eliminating Cdic exons v2 and v3, as well as multiple frameshift deletions or insertions. The new protein becomes incorporated into the tail of the mature sperm and may function as an axonemal dynein intermediate chain. Our current research is focused on understanding the order of events in which the new gene evolved and the functional significance of the mutational changes that were selected.
- Kulathinal, R. J., S. A. Sawyer, C. D. Bustamante, D. I. Nurminsky, R. Ponce, J. M. Ranz, and D. L. Hartl, 2004. Selective sweep in the evolution of a new sperm-specific gene in Drosophila. Pp. 22-33 in Selective Sweeps, Eds. D. I. Nurminsky. Kluwer Acedemic/Plenum, New York, NY.
- Ranz, J. M., A. R. Ponce, D. L. Hartl, and D. Nurminsky, 2003. Origin and evolution of a new gene expressed in the Drosophila sperm axoneme. Genetica 118: 233-244.
- Nurminsky, D., D. De Aguiar, C. D. Bustamante and D. L. Hartl. 2001. Chromosomal effects of rapid gene evolution in Drosophila melanogaster. Science 291: 128-130.
- Nurminsky, D. I. and D. L. Hartl. 1999. How was the Sdic gene fixed? Nature 400: 519-520. PDF Nurminsky, D. I., M. V. Nurminskaya, D. De Aguiar, and D. L. Hartl, 1998 Selective sweep of a newly evolved sperm-specific gene in Drosophila. Nature 396: 572-575.
