Triploidy is also utilized in salmon and trout farming to induce sterility.Rarely, autopolyploids arise from spontaneous, somatic genome doubling, which has been observed in apple (Malus domesticus) bud sports. This is also the most common pathway of artificially induced polyploidy, where methods such as protoplast fusion or treatment with colchicine, oryzalin or mitotic inhibitors are used to disrupt normal mitotic division, which results in the production of polyploid cells. This process can be useful in plant breeding, especially when attempting to introgress germplasm across ploidal levels.Autopolyploids possess at least three homologous chromosome sets, which can lead to high rates of multivalent pairing during meiosis (particularly in recently formed autopolyploids, also known as neopolyploids) and an associated decrease in fertility due to the production of aneuploid gametes. Natural or artificial selection for fertility can quickly stabilize meiosis in autopolyploids by restoring bivalent pairing during meiosis, but the high degree of homology among duplicated chromosomes causes autopolyploids to display polysomic inheritance. This trait is often used as a diagnostic criterion to distinguish autopolyploids from allopolyploids, which commonly display disomic inheritance after they progress past the neopolyploid stage. While most polyploid species are unambiguously characterized as either autopolyploid or allopolyploid, these categories represent the ends of a spectrum of divergence between parental subgenomes.
Overall, the results observed would not have been anticipated in the absence of treatment. The effect of vestronidase alfa on the central nervous system manifestations of MPS VII has not been determined.The FDA approved vestronidase alfa-vjbk based primarily on evidence from one clinical trial (NCT02230566) of 12 participants with mucopolysaccharidosis VII. The trial was conducted at four sites in the United States.The benefit and side effects of vestronidase alfa were based primarily on one trial. Participants were randomly assigned to four groups. Three groups of participants received placebo treatment before starting vestronidase alfa treatment and one group received vestronidase alfa only. vestronidase alfa or placebo were given once every two weeks as intravenous (IV) infusions. Neither participants nor healthcare providers knew which treatment was given until after the trial was competed.The benefit of 24 weeks of vestronidase alfa treatment was primarily evaluated by the 6-minute walking test (6MWT) and compared to placebo treatment in ten participants who could perform the test. The 6MWT measured the distance a patient could walk on a flat surface in 6 minutes. An additional follow-up using 6MWT was done for up to 120 weeks.The application for vestronidase alfa was granted fast track designation, orphan drug designation, and a rare pediatric disease priority review voucher. This was the twelfth rare pediatric disease priority review voucher issued.The U.S. Food and Drug Administration (FDA) granted approval of Mepsevii to Ultragenyx Pharmaceutical, Inc, and required the manufacturer to conduct a post-marketing study to evaluate the long-term safety of the product. References
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"Vestronidase alfa".