. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. TRANSPLANTED GASTROPOD EMBRYOS I/I OVO t'X OVO Dav 0 Dav 3 Dav 3 281 B. Figure 1. Embryonic development of embryos after 3 days of culture in ovo and ex ovo at 23 °C. Examples of stage E15 (A), E20 (B). and E25 (C) embryos before culture (Day 0), after 3 days of culture in host egg capsules (in ovo), and in Helisoma saline plus CF (ex ovo). Embryos cultured in ovo reached stages E40 (A). E45 (B), and E50 (C), whereas embryos cultured ex ovo only developed to stage E30 (A and B) or E35 (C). s: shell gland; arro
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. TRANSPLANTED GASTROPOD EMBRYOS I/I OVO t'X OVO Dav 0 Dav 3 Dav 3 281 B. Figure 1. Embryonic development of embryos after 3 days of culture in ovo and ex ovo at 23 °C. Examples of stage E15 (A), E20 (B). and E25 (C) embryos before culture (Day 0), after 3 days of culture in host egg capsules (in ovo), and in Helisoma saline plus CF (ex ovo). Embryos cultured in ovo reached stages E40 (A). E45 (B), and E50 (C), whereas embryos cultured ex ovo only developed to stage E30 (A and B) or E35 (C). s: shell gland; arrowheads: radular sac; arrows: granular deposition in the protonephridium. Scale bars: 100 urn. We next tested the effect of pH on the growth of isolated embryos. Egg mass matrix and CF had a pH of ± (n = 4), suggesting that low pH may promote embryonic development. The growth and development of stage E20 embryos were assessed after 3 days of culture in HDM adjusted to pH , , or Although none of these groups exhibited significantly improved embryonic devel- opment as compared to the previous treatments, embryo development improved inversely with pH, both in terms of embryo length (Fig. 3A) and percent of embryos displaying stage E30 features, including larval kidney formation, mus- cle contraction of the body wall, and a shell (Fig. 3B). This effect of pH was not observed when embryos were cultured in 30% Ml99 (data not shown), a medium that generally promoted greater embryonic development than HDM, as described above. Because a novel EOF has recently been identified in the CF-secreting albumen gland of Lymnaea stiii>milis (Her- mann et«/.. 2000), we also tested whether EOF can promote the growth and development of Helisoma embryos t'.v ovo. Stage E20 embryos cultured for 3 days in HDM at pH developed similarly, in both stage and body length, in the presence or absence of human recombinant EOF (450 ng/ ml) or Lvninaea EOF (100 ng/ml) (data not shown).
Size: 1710px × 1460px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
