I was involved in a bit of a discussion over twitter this morning over the value of co-corresponding authors on manuscripts. This has inspired a Drugmonkey blog post with some good comments. Because I've actually published a paper with co-corresponding authors (here), I thought that I could provide a slightly different insight into the process.
First off, what does it mean to be a corresponding author? Traditionally, the corresponding author spot on a paper is there in case researchers stumble across your manuscript and have questions or requests for reagents. This has morphed into somewhat of a status symbol with the increase in number of authors on papers because corresponding authors are seen as having "ownership" (for lack of a better word) over the published project. For instance, in the CV for my tenure packet I list where I am the corresponding author on manuscripts from my own lab that my postdoctoral advisor is also an author on. Maybe this matters, maybe it doesn't, but I see it as a way to point out projects that I have taken more of a lead role on.
So after that brief intro, here's my experience with co-corresponding authorship. Back in 2009 we published a paper on sequencing and assembly of a Pseudomonas syringae strain (here). This paper included biological data as well as a computational pipeline to that we used to assemble the genome. My postdoctoral advisor, Jeff Dangl, was the sole corresponding author on this paper. Jeff is an incredible biologist, but is not the best programmer in the world. Dangl was the perfect corresponding author for any biological question (strain/construct requests, etc...) from that paper. However, Jeff would get emailed questions concerning the computational pipeline and inevitably would forward the emails to the people (Corbin Jones and me) that could actually answer them. This was a bit frustrating.
To prevent this situation in our next paper in this series, which expanded this pipeline and analyses across 19 strains, both Corbin and Dangl were corresponding authors with a note that Jeff would handle the biology and Corbin would handle the computational questions.
One important thing to note...in each case the lead author has been the one actually formatting and uploading the paper to the journal, and also dealt with actual correspondance to the editor of the journal after submission without being listed as corresponding author. As many know, those are the most fun and fulfilling parts of manuscript submission...