In my reading over the past couple of weeks, I’ve come across a few new words related to one I posted about here some time back. The topic is worth revisiting, from a more general point of view.
The connectome, to refresh your memory, is a map of the workings of the brain. This might be a strictly physical map, but if the research works out as hoped, it’s more likely to be a functional map as well: it will include not only the locations and connections of most neural pathways but also their relationships and functions. (There are some very cool pictures linked to that older post, so be sure to check it out.)
The term connectome was coined based on the idea of the genome: if a genome catalogs an organism’s genetic makeup, a connectome, then, catalogs its neural structure.
But scientists, no strangers to neologism, know a good thing when they see it. Why stop at genome and connectome? If the words are both adequately descriptive (as they are) and intuitively understood (as they certainly seem to be), why not adopt the -ome suffix for use with other endeavors?
Of course, that’s exactly what they’ve done. Two such words with growing acceptance are proteome and transcriptome. A proteome is concerned with proteins; it’s “the entire complement of proteins that is or can be expressed by a cell, tissue, or organism” (ODO). It’s what those genes in your genome are actually there to do: the genome can be thought of as the instruction manual, the proteome as the objects that are produced when that manual is followed.
A transcriptome, a word that seems not to be in widespread use outside of certain life science sub-specialties, can be thought of as the molecules that are actually active in transmitting (transcribing) genetic instructions. As such, it’s a subset of the proteome, and while both the genome and the proteome for any individual organism are fixed (the number of genes in your body doesn’t change, nor does the number of proteins they’re theoretically capable of producing), the transcriptome is more complicated because it can change with environmental conditions. The transcriptome is the inventory of genes that are being actively expressed at a given time, or under a given set of circumstances.
If I’m not explaining these concepts well (‘Dammit, Jim, I’m an editor, not a biochemist!’), perhaps this page from the Human Genome Project will be helpful. It’s pretty clear, and anyone with an up-to-date understanding of high school biology can probably follow it. This explanation, from the University of Warwick in the UK, might be even more clear.
It’s often interesting how dictionaries note the derivation of words, especially words with meaning or usage that are in motion. The -ome words are a great example of how an original source can get lost, or at least obscured, while the actual meaning is retained or even enhanced. Genome in the ODO, for instance, is noted as the “blend of gene and chromosome.” Proteome, on the other hand, is “a blend of protein and genome.” While the “complete set” idea of genome has been preserved, the source word ‘chromosome’ has been discarded. But the new useful suffix -ome, originally derived from chromosome, has been retained. It’s language evolution caught in the act.
Genome (coined in German in the 1920s, and quickly adopted into English) has already made it into just about every dictionary, as well as into common use, but the rest of these “-omes” have varying degrees of penetration. Proteome (dating to about 1995 by most accounts) can be found in the major dictionaries. Transcriptome so far only shows up in the Oxford family (OED and ODO). The origin of transcriptome is a little trickier to pin down than the others: a paper from 1997 by Velculescu et al. may have been the first use, but that’s not certain. Connectome is the odd one out: so far, it hasn’t made it into any major dictionary.
While the dictionaries that list these words all seem to implicitly recognize -ome as a new suffix, meaning roughly “the full set; the complete catalog,” they haven’t caught up and actually included this definition. So far, they still restrict the suffix -ome to “forming nouns denoting objects or parts having a specific nature” (ODO) such as rhizomes, chromosomes, ribosomes, and so on. AHD goes out on a limb of its own and cites -ome as a suffix meaning “mass,” citing “biome” as an example; I think they’ve got this one wrong, since their own full definition of biome isn’t consistent with this.
What other -omes does the future hold? It wouldn’t surprise me if we see numerous new -ome coinages in the coming decades, first in the life sciences, then in other sciences, and finally in other fields. A software developer might create an -ome word to cover the full set of code for a program; a new -ome word might be devised to describe the complete works of a composer; the full body of commentary on a specific legal issue might be encompassed by an -ome construction. The possibilities are great. Who knows where they could lead? Whether these words will be intended to be taken seriously or meant only as humor, and whether any of these words will be superior to others that already fill these niches, are questions that can’t yet be answered. But it should be entertaining to see how this unfolds.
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Note: Regular readers will have noticed that for the past few months I haven’t been posting as consistently as I used to. In some cases, a month has gone by between posts, when I had previously made a point to post twice per week. Please don’t take that as a sign that this blog is going away: it’s just a reflection of my schedule and the relative strengths of the various things that push and pull on my life. I’ll continue to post as time and energy allow, although perhaps not with the same consistency as in the past. Also, judging by the list of potential topics in front of me at this moment, it looks as if future posts are likely to shift more toward vocabulary and away from grammar and usage. I’ve tried to keep them as close to a 50-50 balance, but down the road vocabulary is likely to dominate, perhaps covering 80% or more of the posts.
I hope you’ll continue to read and to share with your friends and colleagues. Despite the slowdown in posting on my end, the readership and the number of unique clicks per day both continue to steadily increase. I’m careening toward 5000 unique page views, and might just get there by the anniversary of the first post. I’m very grateful to you all. Thanks!