In the eggs of the quail Coturnix japonica, the limiting membrane demarcates the shell membrane at the interface with the albumen and decreases in width during the hatching process. This study was done to identify agents that affect the width of this limiting membrane. Zymography tests on extracts from extraembryonic tissues, yolk sacs, or chorioallantoic membranes, or all three, showed proteol...

We have constructed a cDNA clone library from poly(A)+ RNA of very-late-period choriogenic silkmoth follicles. Clone DNAs that hybridize preferentially to RNA from the aeropyle crown region of the follicle (versus the flat region) were selected, and all could be placed in one of two homology groups. The two groups represent sequences encoding the very-late-period chorion proteins E1 and E2; thi...

Fusions with the bacterial gene for chloramphenicol acetyltransferase followed by P-element-mediated germ-line transformation in Drosophila have permitted localization of the DNA sequence that confers a high degree of developmental specificity on a pair of silkmoth eggshell (chorion) genes. The short, 272-base-pair, 5'-flanking region shared by the divergently transcribed genes is sufficient fo...

dHACM: dehydrated human amnion/chorion membrane INTRODUCTION Mohs surgery and repair of lower eyelid surgical defects present unique reconstruction challenges because of risk for ectropion. There are several options to avoid this adverse outcome, but when a patient declines surgical repair, there are no alternatives aside from second-intention healing with or without adjunctive therapy. One pro...

T H E gradual deposition of a homogeneous, jelly-like covering on the rabbit ovum during its passage down the uterine tube was first observed by Cruikshank in 1797. This observation has been confirmed repeatedly by many later workers (Barry, 1839; Bischoff, 1842; Thomson, 1859; Assheton, 1894; Gregory, 1930; and Pincus, 1936). Barry referred to this covering investing the zona pellucida as 'cho...