The nucleus is an exquisitely adapted structure, no mere repository for DNA. It is composed of structures such as the nucleolus, where new ribosomal RNA is manufactured on a colossal scale; the doubled nuclear membrane, studded with stunningly beautiful protein pore complexes (Figure 26), each one containing scores of proteins conserved across all eukaryotes; and the elastic lamina, a flexible protein meshwork lining the nuclear membrane that protects DNA against shear stress.
