Recyclability of Opaque PET from High Speed Melt Spinning: Determination of the Structures and Properties of Filaments.

Recycling opaque Polyethylene terephthalate (PET), which contains 1 to 10 wt % TiO submicron particles, has become of interest in the past few years. However, the bottle-to-fiber recyclability of opaque PET has not been assessed yet. In this work, opaque PET packaging has been characterized, and high-speed melt-spun filaments with different amounts of opaque PET (30-50-100%) blended with standard transparent recycled PET (rPET) have been produced in a pilot system.

Male Infertility Is Responsible for Nearly Half of the Extinction Observed in the Mouse Collaborative Cross.

The goal of the Collaborative Cross (CC) project was to generate and distribute over 1000 independent mouse recombinant inbred strains derived from eight inbred founders. With inbreeding nearly complete, we estimated the extinction rate among CC lines at a remarkable 95%, which is substantially higher than in the derivation of other mouse recombinant inbred populations. Here, we report genome-wide allele frequencies in 347 extinct CC lines.

The Founder Strains of the Collaborative Cross Express a Complex Combination of Advantageous and Deleterious Traits for Male Reproduction.

Surveys of inbred strains of mice are standard approaches to determine the heritability and range of phenotypic variation for biomedical traits. In addition, they may lead to the identification of novel phenotypes and models of human disease. Surprisingly, male reproductive phenotypes are among the least-represented traits in the Mouse Phenome Database.

Reporter mice express green fluorescent protein at initiation of meiosis in spermatocytes.

Transgenic mice were generated using a heat shock protein 2 (Hspa2) gene promoter to express green fluorescent protein (GFP) at the beginning of meiotic prophase I in spermatocytes. Expression was confirmed in four lines by in situ fluorescence, immunohistochemistry, western blotting, and PCR assays. The expression and distribution of the GFP and HSPA2 proteins co-localized in spermatocytes and spermatids in three lines, but GFP expression was variegated in one line (F46), being present in some clones of meiotic and post-meiotic germ cells and not in others.

Glycolysis and mitochondrial respiration in mouse LDHC-null sperm.

We demonstrated previously that a knockout (KO) of the lactate dehydrogenase type C (Ldhc) gene disrupted male fertility and caused a considerable reduction in sperm glucose consumption, ATP production, and motility. While that study used mice with a mixed genetic background, the present study used C57BL/6 (B6) and 129S6 (129) Ldhc KO mice. We found that B6 KO males were subfertile and 129 KO males were infertile.