Supplementary Materials Supplemental Materials supp_24_14_2256__index. signaling, which contribute to epithelial differentiation and renewal, nor will it affect suckling-to-weaning transition. Consistent with augmented cylindrical growth, suckling but not adult transgenic mice show enlarged crypts and thus more crypt fissions caused by a transient increase of the crypt transit-amplifying zone. Intestinal enlargement by CD97 requires its seven-span transmembrane/cytoplasmic C-terminal fragment but not the N-terminal fragment binding partner CD55. In summary, ectopic expression of CD97 in intestinal epithelial cells provides a unique model for intestinal cylindrical growth occurring in breast-fed 31430-18-9 infants. INTRODUCTION The generation of the mature mammalian intestinal tract entails dramatic morphological changes, yet the mechanisms that underlie intestinal growth after 31430-18-9 birth are largely obscure (Cummins and Thompson, 2002 ). Postnatal growth of the epithelial surface of the small intestine occurs by two growth patterns known as cylindrical and luminal growth, respectively (Cummins and Thompson, 2002 ). In human infants, during milk feeding, cylindrical development, comprising an increase long and size without obvious microscopic morphological changes, predominates and peaks simultaneously with crypt fission, that is, the longitudinal division of crypts during the 1st 12 months (Cummins 0.001), respectively. The megaintestine phenotype correlated with a transgene copy quantity of 10C15 in Tg1, 70C80 in Tg2, and 400 in Tg3 (Becker 0.05), suggesting that at very high copy number, CD97 overexpression also affects the large bowel. Number 2A shows CD97 Western blot analysis of intestinal lysates, and Number 2B shows photos taken 31430-18-9 from the small intestine and 31430-18-9 the cecum of WT, Tg1, Tg2, and CD97 knockout (Ko) mice. Open in a separate window Number 2: Tg(villin-CD97) mice develop megaintestine. (A) CD97 protein manifestation in lysates of the small intestine of two WT, Tg1, Tg2, and CD97Ko mice analyzed by Western blotting using an antibody directed to the CTF of CD97 (Mr, molecular excess weight marker). (B) Photos taken from freshly prepared small intestine and cecum of several mouse strains display the increase in length of the small bowel in Tg2 mice. (C) Size and excess weight of the small intestine improved in adult Tg2 and Tg3 mice (Tg3, = 6; additional strains, = 16; mean SEM; * 0.05, *** 0.001). (D) The increase in excess weight concerned all segments of the small bowel but was more pronounced in the duodenum (duo) and jejunum (jeju). Variations were self-employed of feces content material (*** 0.001). (E) Cross-sectional diameter increased in all segments of the small bowel in Tg2 mice (*** 0.001). (F) Daily food intake and drinking ad libitum and the amount of feces were similar between mouse strains (= 10/strain). Intestinal enlargement in Tg2 mice involved all three segments of the tiny colon but was even more pronounced in the duodenum and jejunum and unbiased of feces articles (Amount 2D). Morphometric evaluation revealed an increase in diameter in each section of the small bowel (Number 2E). Food and water intake at random per day was similar between WT and Tg mice, as was the amount of feces (Number 2F). CD97 overexpression does not impact intestinal microscopic morphology in adult mice We next analyzed the small intestine of adult Tg2 mice in the microscopic level. We found no variations in 1) the thickness of the cells layers, that is, muscosa, submucosa, and muscularis (data not demonstrated); 2) the denseness, shape, size, and width of the villi (Number 3A) and the depth and width of the crypts (Number 3B); 3) the number of crypts feeding a single villus, the real amount and design of villi and crypts per region, as well as the percentage of DNM2 crypt fissions (Amount 3C); 4) the distance and width of intestinal epithelial cells and therefore the amount of epithelial cells/villus (data not really proven); 5) the dedication of multipotential resorptive and secretory precursor 31430-18-9 cells, as could be concluded from mRNA degrees of intestinal enzymes required.