Cultured cells derived from transgenic animals have not generally been utilized to investigate questions in cell biology; however, to study the properties of proteins from the lens of the eye, a cell line which synthesizesα-crystallin was established from a transgenic mouse. All theα-crystallins,αA,αB, and alnsert, accumulate in the cell line. Theα-crystallin, 1.6% of the cellular protein, is found in large molecular weight aggregates similar to the aggregates found in the normal mouse lens. Theα-crystallins in the lens cells correspond exactly to both the unmodified and the phosphorylatedα-crystallins found in the lens of the mouse, suggesting that some post-translational modification of the mouseα-crystallin may be important to the structure of this protein.