Possible Patterns of Differentiation in the Primitive Ectoderm of C3H/HeNBALB/cA Chimeric Blastocysts: An Inference from Quantitative Analysis of Coat‐Color Patterns

Abstract

Coat-color patterns of 20 C3H/HeNoBALB/cA chimeras produced by using the same colony of mice in a series of experiments, were quantitatively analyzed, by means of a video-image analysis system developed by Tachi (1988Tachi ( , 1989. In those chimeras, proportion of the two allogeneic components, i.e., C3H/HeN and BALB/cA, was relatively well balanced between the right and the left halves of the pelts, whereas between the anterior and the posterior regions it was unbalanced in favor of BALBIcA components in the anterior region. To interpret the results, a computerized geometrical model intended to simulate the hypothetical conditions of chimeric germ layers during early embryogenesis, was constructed. From the model, it was proposed that the seemingly high selection pressure for the BALB/cA components in the anterior region of this particular group of chimeras, might have been caused because the initial steps of the determination of the cranio-caudal axis took place in the regions of the primary ectoderm where BALBIcA, rather than C3HIHeN blastomeres were predominant. Possible variations in the alleles of the genes regulating the germ layer differentiation, might conceivably be the cause for the observed tendencies.

Quantitative analysis of patch patterns in mosaic tissues with ClonalTools software

“…(2009) analysed 187 images representing five ages between 15 and 52 weeks and demonstrated a clear, statistically significant decline in the number of corrected stripes between 15 and 39 weeks from 88.33 ± 8.06 to 52.71 ± 5.79 (corrected stripe number ± 95% confidence interval). Although other mosaic patterns have been imaged and analysed by computer (Tachi, 1988; Tachi et al. 1991), to the best of the author’s knowledge no computerized image analysis approach for conducting a quantitative clonal analysis has so far been proposed or successfully validated for radial patterns such as those seen in the corneal‐epithelium.…”

Quantitative Analysis of Coat-color Patterns in BALB/c .DARRLR. C57BL/6 Mouse Chimeras by Means of a Computer-Based Color Image Processor System.

“…Tachi [9,10,12,13] pioneered in developing a microcomputer- based program package for quantitative analysis of coat-color patterns in artificially produced chimeras; the used 256 × 256 pixel matrix for the purpose. A similar system currently employs an image processor with 480 × 512 pixels resulting in an improved resolution.…”

“…This suggests that the proportion of C57BL/6 was higher along the axial skeleton temporal gradient and the C3H type in the vertebrae column. Tachi [9,10,13] reported his results on the quantitative analysis of the coat-color patterns of C3H/ HeN BALB/c chimeras produced by using the same colony of mice in a series of experiments. In these chimeras, the proportion of C3H/HeN and BALB/cA components, was relatively well balanced between the right and the left halves although it was unbalanced the between the anterior and the posterior regions in favor of BALB/c components in the anterior region.…”

“…In these chimeras, the proportion of C3H/HeN and BALB/cA components, was relatively well balanced between the right and the left halves although it was unbalanced the between the anterior and the posterior regions in favor of BALB/c components in the anterior region. A high selection pressures for the BALB/cA components appeared to exist in the anterior region [13]. Mullen [19] described the distribution of purkinje cells in chimeras as being almost randomly distributed.…”