1. Leukemia inhibitory factor induces cumulus expansion in immature human and mouse oocytes and improves mouse two-cell rate and delivery rates when it is present during mouse in vitro oocyte maturation 
Daniel G. De Matos, Ph.D., Kathleen Miller, B.S., Richard Scott, M.D., Cam Anh Tran, M.Sc., David Kagan, M.Sc., Selva G. Nataraja, Ph.D., Ann Clark, Ph.D., Stephen Palmer, Ph.D. 
Fertility and Sterility 
Volume 90, Issue 6, Pages (December 2008)
DOI: /j.fertnstert
Copyright © 2008 American Society for Reproductive Medicine Terms and Conditions

2. Figure 1
Percentage of cumulus oocyte complexes (COCs) with cumulus expansion in the in vitro maturation (IVM) assay in the presence of different leukemia inhibitory factor (LIF) concentrations. Data are expressed as mean ± standard deviation of three independent experiments (n = 3) containing 15 COCs per experiment for each concentration (total 45 oocytes). Different letters within points denote a statistically significant difference (P<.05).
Fertility and Sterility  , DOI: ( /j.fertnstert )
Copyright © 2008 American Society for Reproductive Medicine Terms and Conditions

3. Figure 2
Human cumulus expanded oocytes after IVM. In vitro matured (IVM) oocytes either matured in human IVM medium without recombinant FSH (negative control); in IVM medium supplemented with recombinant FSH (positive control) (0.2 IU/mL) or in IVM medium supplemented with leukemia inhibitory factor (LIF) (1000 ng/mL). Pictures were taken at the start of IVM (T0) and after 48 hours of IVM (T48). Magnification: A, B, C, and E, ×200; D and F, ×100. Cumulus expansion was induced by LIF as well as FSH (D and F). Attachment to the dish of the external cumulus cell but not cumulus expansion can be seen on oocytes matured in IVMst alone (A) (negative control).
Fertility and Sterility  , DOI: ( /j.fertnstert )
Copyright © 2008 American Society for Reproductive Medicine Terms and Conditions

4. Figure 3
Percentage of two-cell embryos and blastocysts per total oocytes exposed to sperm. Oocytes were in vitro matured in mouse-standard (IVMst) medium (black column) supplemented with 0.2 IU/mL of recombinant FSH alone (turquoise column) or with leukemia inhibitory factor (LIF; , 1.0, or 0.1 ng/mL) either in the presence (green columns) or absence (orange columns) of recombinant FSH (0.2 IU/mL). In vivo matured oocytes (ovulated oocytes, blue column) were in vitro fertilized at the same time. All IVM oocytes underwent IVF at the same time at 24 hours and at day 4 (day 0 = day of IVF) the number of two-cell embryos and blastocysts were counted. The experiment was repeated six times (n = 6). Each replicate was conducted on different days with a different batch of oocytes. Data are expressed as mean ± SEM. Columns with different letters denote statistically significant differences (P<.05).
Fertility and Sterility  , DOI: ( /j.fertnstert )
Copyright © 2008 American Society for Reproductive Medicine Terms and Conditions

5. Figure 4
Embryo development results: percentage of blastocyst per two-cell embryos. Oocytes were in vitro matured in mouse-standard (IVMst) medium (black columns) supplemented with 0.2 IU/mL of recombinant FSH alone (turquoise column) or with leukemia inhibitory factor (LIF; , 1.0, 0.1 ng/mL) either in the presence (green columns) or absence (orange columns) of recombinant FSH (0.2 IU/mL). In vivo matured oocytes (ovulated oocytes) were in vitro fertilized at the same time (blue column). All IVM oocytes underwent IVF, and after 24 hours the number of two-cell embryos was counted and cultured up to day 4 (day 0 = day of IVF). The experiment was repeated six times (n = 6). Each replicate was conducted at different days with different batch of oocytes. Data are expressed as mean ± SEM. Columns with different letters denote statistically significant differences (P<.05).
Fertility and Sterility  , DOI: ( /j.fertnstert )
Copyright © 2008 American Society for Reproductive Medicine Terms and Conditions

6. Figure 5
Embryo transfer results: percentage of total births. Oocytes were in vitro matured in mouse-standard (IVMst) medium supplemented with 0.2 IU/mL of recombinant FSH alone (turquoise column) or with leukemia inhibitory factor (LIF; , 1.0, 0.1 ng/mL) either in the presence (green columns) or absence (orange columns) of recombinant FSH (0.2 IU/mL). In vivo matured oocytes (ovulated oocytes) were in vitro fertilized at the same time (blue column). Day-3.5 blastocysts were transferred (day 0 = IVF-day). The experiment was repeated four times (n = 4). Each replicate was conducted on different days with a different batch of oocytes. Data are expressed as mean ± SEM. Columns with different letters denote statistically significant differences (P<.05). A total of 7 to 12 embryos were transferred per female in each group, and the total number of transferred embryos is expressed in each column.
Fertility and Sterility  , DOI: ( /j.fertnstert )
Copyright © 2008 American Society for Reproductive Medicine Terms and Conditions