SV40 T-antigen-expressing human cells generally have an extension of lifespan until a period called "crisis" begins. On rare occasions a clone of cells emerges from the population in crisis and gives rise to an immortalized cell line. The present study compares the frequency of immortalization of cells from two different human lineages, lung fibroblasts and mammary epithelial cells.
Insertions or deletions (indels) of amino acids residues have been recognized as an important source of genetic and structural divergence between paralogous Bcl-2 family members. However, these signature sequences have not so far been extensively investigated amongst orthologous Bcl-2 family proteins. Bcl2l10 is an antiapoptotic member of the Bcl-2 family that has evolved rapidly throughout the vertebrate lineage and which shows conserved abundant expression in eggs and oocytes.
Mammalian Genome: Official Journal of the International Mammalian Genome Society
Prader-Willi syndrome (PWS) results from loss of function of a 1.0- to 1.5-Mb domain of imprinted, paternally expressed genes in human Chromosome (Chr) 15q11-q13. The loss of imprinted gene expression in the homologous region in mouse Chr 7C leads to a similar neonatal PWS phenotype. Several protein-coding genes in the human PWS region are intronless, possibly arising by retrotransposition. Here we present evidence for continued acquisition of genes by the mouse PWS region during evolution.
BACKGROUND: Classical and quantitative linkage analyses of genetic crosses have traditionally been used to map genes of interest, such as those conferring chloroquine or quinine resistance in malaria parasites. Next-generation sequencing technologies now present the possibility of determining genome-wide genetic variation at single base-pair resolution. Here, we combine in vivo experimental evolution, a rapid genetic strategy and whole genome re-sequencing to identify the precise genetic basis of artemisinin resistance in a lineage of the rodent malaria parasite, Plasmodium chabaudi.
Currently, the species Bifidobacterium animalis consists of two subspecies, B. animalis subsp. lactis and B. animalis subsp. animalis. Among these two subspecies, B. animalis subsp. lactis is especially important because it is widely used in the manufacture of probiotic dairy products. The application of these microbes in the food industry demands fast, accurate and low cost methods to differentiate between species and strains.
The sigma(X) and sigma(W) extracytoplasmic function sigma factors regulate more than 40 genes in Bacillus subtilis. sigma(W) activates genes which function in detoxification and the production of antimicrobial compounds, while sigma(X) activates functions that modify the cell envelope. Transposon mutagenesis was used to identify loci which negatively regulate sigma(W) or sigma(X) as judged by up-regulation from the autoregulatory promoter site P(W) or P(X). Fourteen insertions that activate P(W) were identified. The largest class of insertions are likely to affect transport.
Aging is genetically determined and environmentally modulated. In a study of longevity in the adult fruit fly, Drosophila melanogaster, we found that five independent P-element insertional mutations in a single gene resulted in a near doubling of the average adult life-span without a decline in fertility or physical activity. Sequence analysis revealed that the product of this gene, named Indy (for I'm not dead yet), is most closely related to a mammalian sodium dicarboxylate cotransporter-a membrane protein that transports Krebs cycle intermediates.