Large-scale transitions in genome size from tetraploid to diploid were observed during a previous 1800-generation evolution experiment in Saccharomyces cerevisiae. Whether the transitions occurred via a one-step process (tetraploid to diploid) or through multiple steps (through ploidy intermediates) remained unclear. To provide insight into the mechanism involved, we investigated whether triploid-sized cells sampled from the previous experiment could also undergo ploidy loss. A batch culture experiment was conducted for approximately 200 generations, starting from four triploid-sized colonies and one contemporaneous tetraploid-sized colony. Ploidy reduction towards diploidy was observed in both triploid and tetraploid lines. Comparative genomic hybridization indicated the presence of aneuploidy in both the founder and the evolved colonies. The specific aneuploidies involved suggest that chromosome loss was not haphazard but that nearly full sets of chromosomes were lost at once, with some additional chromosome mis-segregation events. These results suggest the existence of a mitotic mechanism allowing the elimination of an entire set of chromosomes in S. cerevisiae, thereby reducing the ploidy level.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2412927 | PMC |
http://dx.doi.org/10.1098/rsbl.2007.0476 | DOI Listing |
BMC Pregnancy Childbirth
December 2024
Reproductive Medical Center, Henan Province Key Laboratory of Reproduction and Genetics, The First Affiliated Hospital of Zhengzhou University, No. 1 East Jianshe Road, Erqi District, Zhengzhou, China.
Research Question: Is it possible to predict blastocyst quality, embryo chromosomal ploidy, and clinical pregnancy outcome after single embryo transfer from embryo developmental morphokinetic parameters?
Design: The morphokinetic parameters of 1011 blastocysts from 227 patients undergoing preimplantation genetic testing were examined. Correlations between the morphokinetic parameters and the quality of blastocysts, chromosomal ploidy, and clinical pregnancy outcomes following the transfer of single blastocysts were retrospectively analyzed.
Results: The morphokinetic parameters of embryos in the high-quality blastocyst group were significantly shorter than those in the low-quality blastocyst group (p < 0.
Cell Biochem Funct
December 2024
Laboratory of Biochemistry and Molecular Biology, Kyoto Pharmaceutical University, Kyoto, Japan.
TNK2 is a ubiquitously expressed nonreceptor-type tyrosine kinase. TNK2 participates in tumorigenesis, and TNK2 activation has been found in various cancers; therefore, TNK2 is a promising target for cancer chemotherapy. While the TNK2 inhibitor XMD16-5 is highly selective, it inhibits cytokinesis at higher concentrations by targeting Aurora B kinase, a key enzyme for cell division.
View Article and Find Full Text PDFJ Cell Sci
January 2025
Key Laboratory of Cell Proliferation and Regulation Biology of Ministry of Education, Center for Biological Science and Technology, Guangdong Zhuhai-Macao Joint Biotech Laboratory, Beijing Normal University, Zhuhai 519087, China.
Controlling organ size in plants is a complex biological process influenced by various factors, including gene expression, genome ploidy and environmental conditions. Despite its importance for plant growth and development, the mechanisms underlying organ size regulation remain unknown. Here, we investigated the role of RAN1, a member of the Ras-related nuclear GTPase family, in regulating pollen size.
View Article and Find Full Text PDFFront Endocrinol (Lausanne)
November 2024
Medical Integration and Practice Center, Shandong University, Jinan, Shandong, China.
The safety and clinical effectiveness of preimplantation genetic testing for aneuploidy (PGT-A) in improving pregnancy outcomes for sub-fertile patients remains controversial. Potential sex-based differences in the relationship between PGT-A and pregnancy complications have not been investigated, which could guide the appropriate clinical application of PGT-A. In this secondary analysis of data from a multicenter, randomized, controlled, non-inferiority trial (NCT03118141), 940 women who achieved singleton live birth during the trial were included to estimate the between-group differences in pregnancy complications following PGT-A versus conventional fertilization (IVF) vary with fetal sex.
View Article and Find Full Text PDFInt J Biol Macromol
December 2024
Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, China; Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao Marine Science and Technology Center, Qingdao 266237, China. Electronic address:
Triploid Pacific oyster Crassostrea gigas exhibits notable differences in fecundity, with the majority being sterile individuals, referred to as female β, which produce few oocytes, while a minority are fertile individuals, referred to as female α, which produce abundant oocytes. However, the molecular mechanisms underlying these differences in triploid fecundity remain poorly understood. CDC42 has been implicated in processes related to increased DNA damage and genomic instability.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!