Figure 2

dss-1 deletion results in defects in oogenesis and intestinal absorption. A. dss-1 gene is disrupted in the tm370 allele by a deletion spanning exon 2. B. dss-1(tm370) adults are sterile and thinner than control heterozygotes. Oocytes (C) and embryos (F) are visible in a control dss-1 heterozygote but dss-1 homozygotes have no (D) or only a few oocytes (E). G. Structures resembling embryos are occasionally seen in the uterus of dss-1 homozygotes. Asterisk, spermatheca; e, embryo or embryo-like structure; g, gonad; i, intestine; o, oocyte; u, uterus. H. The average number of oocytes in dss-1 homozygotes is reduced. Oocytes were identified either by Nomarski optics or by DAPI staining. n, number of individual gonad arms examined; ND, not determined. I. Spermatocytes (arrow) are still present in a dss-1 homozygote. I'. DAPI staining. Asterisk marks the more differentiated spermatids. J. Intestinal epithelial cell nuclei can be visualized by DAPI staining in a control N2 L4 worm. K. In dss-1 homozygotes an expanded intestinal lumen filled with bacteria can be seen. L. The pharynx is often twisted, possibly by pressure from the enlarged intestine.