Worm numbers

This page is intended to become a collection ground for useful and interesting numbers about C. elegans biology. These numbers include things such as the average volume and mass (calculated estimates) of an adult hermaphrodite, larval stage, or embryo. Some of these numbers are well established facts whereas others are estimations, with a description of the method for calculating or estimating provided.

Worm Volume

Based on these images from Worm Atlas (www.wormatlas.org):

... where the scale bar represents 100 microns, we can roughly deduce the volume of the embryo, each larval stage worm, and the adult hermaphrodite of C. elegans.

Single embryo = ~35 picoliters

Single L1 larva = ~80 picoliters

Single L2 larva = ~135 picoliters

Single L3 larva = ~300 picoliters

Single L4 larva = ~800 picoliters

Single Adult hermaphrodite = ~2.2 nanoliters

Worm Mass

Assuming the worm has a density close to that of water (1 gram per milliliter) these are estimates of mass:

Single Embryo = ~35 nanograms

Single L1 larva = ~80 nanograms

Single L2 larva = ~135 nanograms

Single L3 larva = ~300 nanograms

Single L4 larva = ~800 nanograms

Single Adult hermaphrodite = ~2.2 micrograms

DNA Numbers

Knowing that a single complete turn of DNA is approximately 3.4 nanometers in length (34 Ångstroms), 2 nanometers in width (20 Ångstroms), and is about 10 base pairs (bp)(and therefore 1 base pair is .34 nanometers long (3.4 Ångstroms)), we can deduce the volume of a single base pair of DNA to be roughly 1 cubic nanometer (1 nm^3):

Assuming a base pair is like a short cylinder with volume:

Volume = (pi)*(radius)^2*(height)

Volume = (~3.14)*(~1nm)^2*(~.34nm)

Volume = ~1 nm^3

Therefore:

1. bp -> Volume

1bp -> 1 cubic nanometer 1kb -> 1000 cubic nanometers = 10^-6 cubic microns 1Mb -> 10^6 cubic nanometers = 10^-3 cubic microns 1Gb -> 10^9 cubic nanometers = 1 cubic micron

So, a single haploid genome of C. elegans (~100Mb) would be approximately 0.1 cubic microns and a diploid genome approximately 0.2 microns. Packed into spheres, these would each be:

Volume of sphere = (4/3)*(pi)*(radius)^3

Haploid genome radius = ~0.29 microns Haploid genome diameter = ~0.58 microns

Diploid genome radius = ~0.36 microns Diploid genome diameter = ~0.72 microns

That is the smallest sphere that the haploid and diploid genomes, respectively, could pack into.