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The Emergence Of Sex, Ursula Goodenough
The Emergence Of Sex, Ursula Goodenough
Biology Faculty Publications & Presentations
Biological traits, the foci of natural selection, are by definition emergent from the genes, proteins, and other “nothing-buts” that constitute them. Moreover, and with the exception of recently emergent “spandrels,” each can be accorded a teleological dimension—each is “for” some purpose conducive to an organism's continuation. Sex, which is “for” the generation of recombinant genomes, may be one of the most ancient and ubiquitous traits in biology. In the course of its evolution, many additional traits, such as gender and nurture, have emerged. Patterns of sexual exchange are the basis for patterns of biological evolution and are central to the …
Drosophila Piwi Associates With Chromatin And Interacts Directly With Hp1a, Brent Brower-Toland, Seth Findley, Ling Jiang, Li Liu, Hang Yin, Monica Dus, Pei Zhou, Sarah C.R. Elgin, Haifan Lin
Drosophila Piwi Associates With Chromatin And Interacts Directly With Hp1a, Brent Brower-Toland, Seth Findley, Ling Jiang, Li Liu, Hang Yin, Monica Dus, Pei Zhou, Sarah C.R. Elgin, Haifan Lin
Biology Faculty Publications & Presentations
The interface between cellular systems involving small noncoding RNAs and epigenetic change remains largely unexplored in metazoans. RNA-induced silencing systems have the potential to target particular regions of the genome for epigenetic change by locating specific sequences and recruiting chromatin modifiers. Noting that several genes encoding RNA silencing components have been implicated in epigenetic regulation in Drosophila, we sought a direct link between the RNA silencing system and heterochromatin components. Here we show that PIWI, an ARGONAUTE/PIWI protein family member that binds to Piwi-interacting RNAs (piRNAs), strongly and specifically interacts with heterochromatin protein 1a (HP1a), a central player in heterochromatic …
Transcription And Rna Interference In The Formation Of Heterochromatin, Shiv Grewal, Sarah C.R. Elgin
Transcription And Rna Interference In The Formation Of Heterochromatin, Shiv Grewal, Sarah C.R. Elgin
Biology Faculty Publications & Presentations
Transcription in heterochromatin seems to be an oxymoron--surely the 'silenced' form of chromatin should not be transcribed. But there have been frequent reports of low-level transcription in heterochromatic regions, and several hundred genes are found in these regions in Drosophila. Most strikingly, recent investigations implicate RNA interference mechanisms in targeting and maintaining heterochromatin, and these mechanisms are inherently dependent on transcription. Silencing of chromatin might involve trans-acting sources of the crucial small RNAs that carry out RNA interference, but in some cases, transcription of the region to be silenced seems to be required--an apparent contradiction.