These genes have the instructions for making the green pigment chlorophyll, for making all the parts needed to turn sunlight into sugar (aka photosynthesis), and for making chloroplasts. Chloroplasts are the part of a plant cell where chlorophyll lives and where photosynthesis happens. And they may actually make solving this little puzzle a little simpler.
Chloroplasts, like mitochondria, have their own DNA. Not a lot, but they do have something like 100 or so genes (the exact number depends on the plant). This DNA is a remnant of plants’ evolutionary past.
A billion or two years ago, some ancestor to the modern plant engulfed a cyanobacterium. After many years, this cyanobacterium became a chloroplast.
In this process, most of the cyanobacterium’s genes migrated to the nucleus. But a few stayed behind. If the albino redwood has chloroplasts (even just sad little precursors called proplastids) and the reason for the albinism is a mutation in one of the chloroplast genes, then we might find our answer sooner rather than later.
This is true for a couple of reasons. First, there can be up to fifty copies of chloroplast genes in a plant cell. And second, the chloroplast genome is tiny. Both of these reasons mean scientists will need to do a lot less sequencing to read the chloroplast genome.
Of course, the mutation may not be in the chloroplast. But if not, then hopefully it will be in one of the known genes involved in making chlorophyll and/or chloroplasts. If so, then we still may get our answer sooner since we’ll be able to scan the DNA for these genes and look for differences.
I’ll keep you updated as progress gets made. It is so cool to have the tools needed to solve a mystery like this. This is why I love science and why you should too. The chance to figure something out that no one else has.
