Complete information on the number of cells and morphological score on days two and three, ICM score, trophectoderm score and expansion status was available for 206 embryos.
We then evaluated the effect of male age on the average morphological score of the embryos transferred to the recipient, which we took as an indication of the quality of the cohort of embryos generated.
The gene expression data were correlated to clinical data and morphological scores.
Logistic regression analysis was performed to assess the association between number of cells on day two and three, morphological score day two and three, ICM score, trophectoderm score and expansion status with the success of establishing a new hESC line.
On the other hand, relatively unexplored, complementary technique based on flow cytometry has not been standardized till date, particularly due to the lack of a proper morphological scoring scale.
A variety of morphological scoring systems are described[ 2, 3].
On day 6, embryos were removed and analyzed for gross malformations and scored according to established morphological scoring criteria (described by Memon and Pratten 2009) [see Supplemental Material, Table S1 (http://dx.doi.org/10.1289/ehp.1205659)].
A complex grading system (MOMS MIII oocyte morphological score) has been established recently by Rienzi et al. (2008) according to the impact of different oocyte morphological features (vacuoles, abnormal PB1, large perivitelline space, diffused cytoplasmic granularity and/or centrally located granular area) on fertilization rate, and pronuclear and embryo morphology.
Using simple morphological data scored on the sampled animals, we also show that a strongly heterogeneous distribution of tortoise sizes on Española Island observed today is due to a large variance in the number of animals included in yearly repatriation events performed in the last 40 years.
