Leukocyte migration - chemotactic responsiveness. Maternal peripheral leukocytes from GD17, 20 and 22 were tested in chemotaxis assays using extracts from uterine segments (A) and cervix (B) obtained on GD22. Uterine (C) and cervical (D) protein extracts of tissues on GD17, 20 and 22 were tested with leukocytes on GD22. Data are presented as mean ± SEM of attracted leukocytes in triplicate by each group of tissues (n=5 each). Means with different letters are significantly different. P values: A) a vs. b p<0.0001, b vs. c p=0.024, a vs. c p=0.005; B) a vs. b p<0.05; C) a vs. b p< 0.009.