Chemotaxis - Modes of Cell Movement

Chemotaxis considers to me directed movement of cells in response to a concentration gradient of a chemical factor in solution. An instance of chemotaxis during morphogenesis of the embryo is the migration of embryonic lymphocytes from bone marrow to embryonic thymus. The compound accountable for the directed movement of cells is shown to be a heat-stable peptide with a molecular weight of 1000 to 4000 daltons. The peptide is almost certainly produced by the thymus. The gradient of the peptide would be highest in the thymus towards that the cells move.