No abstract

Although the identification of specific genes that regulate apoptosis has been a topic of intense study, little is known of the role that background genetic variance plays in modulating cell death. Using germ cells from inbred mouse strains, we found that apoptosis in mature (metaphase II) oocytes is affected by genetic background through at least two different mechanisms. The first, manifested in AKR/J mice, results in genomic instability. This is reflected by numerous DNA double-strand breaks in freshly isolated oocytes, causing a high apoptosis susceptibility and impaired embryonic development following fertilization. Microinjection of Rad51 reduces DNA damage, suppresses apoptosis and improves embryonic development. The second, manifested in FVB mice, results in dramatic dimorphisms in mitochondrial ultrastructure. This is correlated with cytochrome c release and a high apoptosis susceptibility, the latter of which is suppressed by pyruvate treatment, Smac/DIABLO deficiency, or microinjection of 'normal' mitochondria. Therefore, background genetic variance can profoundly affect apoptosis in female germ cells by disrupting both genomic DNA and mitochondrial integrity.

Generally, in order to obtain reliable gas solubility data in a polymer melt, one must determine the swollen volume of the polymer with dissolved gas. The swollen volume is typically estimated by an equation of state (EOS). This paper reports on the application of three different equations of state (the Sanchez-Lacombe (SL) EOS, the Simha-Somcynsky (SS) EOS, and the Perturbed Chain Statistical Associating Fluid Theory (PC-SAFT) EOS) to a polymer/gas mixture system for the study of phase equilibria and gas solubility determination. The apparent solubility was obtained using a magnetic suspension balance (MSB). Approaches based on the SL, SS, and PC-SAFT EOS's are herein proposed for predicting the swelling behavior of polymer/gas mixtures and correlating the swollen volume to the apparent solubility.