Howard M. Laten
Ph.D., 1978, Univ. of Wisconsin-Madison
Area of Research: Plant Retrotransposons
Our investigations are focused on the characterization of plant retrotransposons – a class of repetitive genetic elements embedded in the genomes of their hosts – and how they impact on the evolution of plants and plant genomes. We are also focused on determining the function of a gene found in several plant retrotransposon families whose translated mRNA may resemble that of an envelope protein found in mammalian viruses, including retroviruses like HIV. Retrotransposons are the most abundant kind of DNA in the genomes of virtually all plants and animals. In many plants and some animals, including humans, they constitute more than 80% of chromosomal DNA. They are capable of self-replication and utilize the enzyme reverse transcriptase to sponsor the replication of their small genomes. Unlike their retrovirus cousins, they are non-infectious and are transmitted from one generation to the next through the germ-line. Once considered by many molecular geneticists to be pesky genetic parasites and dubbed "selfish DNA", they are now considered to play major roles in chromosome transmission, gene expression, mutation, epigenetic regulation, genome rearrangement, and the evolution of species. They may more appropriately be called evolution-inducing symbionts.
We are using both experimental and bioinformatics approaches to explore these questions in the genomes of legumes, specifically soybean and clover. In the former we are focusing on the functional characterization of a recently active family of elements that possess an unusual coding region. In the latter we are examining the role that interspecies hybridization plays in retrotransposon activation and amplification.
Sbrocchi, A.J. & Laten, H.M. 2013. Consensus sequence of a SIRE1-related element from red clover (Trifolium pratense L).Repbase Rep. 13: 1229-1230.
Laten, H.M. & Gaston, G.D. 2012. Plant Endogenous Retroviruses? A Case of Mysterious ORFs. In: Topics in Current Genetics: Plant Transposable Elements - Impact on Genome Structure & Function, M.-A. Grandbastien and J.M. Casacuberta, eds., Springer, New York, pp. 89-112.
Mogil, L.S. Slowikowski, K. & Laten, H.M. 2012. Computational and experimental analyses of retrotransposon-associated minisatellite DNAs in the soybean genome. BMC Bioinformatics 13: S13.
Laten, H.M. and Bousios, A. 2012. The Sireviruses, In Springer Index of Viruses, Second Edition, C. Tidona and G. Darai, eds., Springer, New York, pp. 1561-1564.
Du, J., Tian, Z., Hans, C., Laten, H.M., Jackson, S.A., Cannon, S.B., Shoemaker R.C. & Ma J. 2010. Evolutionary conservation, diversity and specificity of LTR-retrotransposons in flowering plants: new insights from genome-wide analysis and multi-specific comparison. Plant J. 63: 584-598.
Laten, H.M., Mogil, L.S. & Wright, L.N.. 2009. A shotgun approach to discovering and reconstructing consensus retrotransposons ex novo from dense contigs of short sequences derived from Genbank Genome Survey Sequence database records. Gene 448: 168–173.
Flasch, D.A., Rebman, E.K., Olfson, E.H., Nguyen, K.K., Geirut, L.E., Garland, M.C., Lindorfer, C.M., & Laten, H.M. 2008. Analysis of insertional sites of the SIRE1 retroelement family from Glycine max using GenBank BAC-end sequences. In Silico Biol 8: 531-543.
Cladogram depicting SIRE-1's relationship to other retroelements.