Telomerase is an enzyme that adds repeats of DNA sequences to the ends of chromosomes, thereby preventing their shortening. Telomerase activity is associated with proliferative status of cells, organismal development, and aging. We report an analysis of telomerase activity and telomere length in the honeybee, Apis mellifera. Telomerase activity was found to be regulated in a development and caste-specific manner. During the development of somatic tissues of larval drones and workers, telomerase activity declined to 10 % of its level in embryos and remained low during pupal and adult stages but was upregulated in testes of late pupae, where it reached 70 % of the embryo level. Upregulation of telomerase activity was observed in the ovaries of late pupal queens, reaching 160 % of the level in embryos. Compared to workers and drones, queens displayed higher levels of telomerase activity. In the third larval instar of queens, telomerase activity reached the embryo level, and an enormous increase was observed in adult brains of queens, showing a 70-fold increase compared to a brain of an adult worker. Southern hybridization of terminal TTAGG fragments revealed a high variability of telomeric length between different individuals, although the same pattern of hybridization signals was observed in different tissues of each individual.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1007/s00412-015-0547-4 | DOI Listing |
J Pediatr Surg
December 2024
Department of Surgery, St. Jude Children's Research Hospital, Memphis, Tennessee, USA. Electronic address:
Background: Patients with diffuse anaplastic Wilms tumor (DAWT) experience relatively poor oncologic outcomes. Previous work has described mechanisms of telomerase upregulation in DAWT, posing a potential therapeutic target.
Methods: We assessed in vitro sensitivity to vincristine, irinotecan, and telomerase-targeting drug 6-thio-2'-deoxyguanosine (6 dG) in DAWT cell lines WiT49 and PDM115 and in spheroids derived from cell lines and four DAWT patient-derived xenografts (PDX).
Sci Adv
January 2025
Department of Biochemistry and Molecular Biology, Tulane University School of Medicine, Louisiana Cancer Research Center, 1700 Tulane Avenue, New Orleans, LA 70112, USA.
Unlike most species that use telomerase for telomere maintenance, many dipterans, including , rely on three telomere-specific retrotransposons (TRs)-, , and -to form tandem repeats at chromosome ends. Although TR transcription is crucial in their life cycle, its regulation remains poorly understood. This study identifies the Mediator complex, E2F1-Dp, and Scalloped/dTEAD as key regulators of TR transcription.
View Article and Find Full Text PDFSci Rep
December 2024
Department of Psychiatry and Behavioral Sciences and Weill Center for Neurosciences, University of California, San Francisco, CA, 94107, USA.
Telomere attrition is a hallmark of biological aging, contributing to cellular replicative senescence. However, few studies have examined the determinants of telomere attrition in vivo in humans. Mitochondrial Health Index (MHI), a composite marker integrating mitochondrial energy-transformation capacity and content, may be one important mediator of telomere attrition, as it could impact telomerase activity, a direct regulator of telomere maintenance.
View Article and Find Full Text PDFFront Endocrinol (Lausanne)
December 2024
Department of Obstetrics and Gynecology, Hefei Maternal and Child Health Hospital, Hefei, China.
Objective: Gestational diabetes mellitus (GDM) is a common complication during pregnancy and increases the risk of metabolic diseases in offspring. We hypothesize that the poor intrauterine environment in pregnant women with GDM may lead to chromosomal DNA damage and telomere damage in umbilical cord blood cells, providing evidence of an association between intrauterine programming and increased long-term metabolic disease risk in offspring.
Methods: We measured telomere length (TL), serum telomerase (TE) activity, and oxidative stress markers in umbilical cord blood mononuclear cells (CBMCs) from pregnant women with GDM (N=200) and healthy controls (Ctrls) (N=200) and analysed the associations of TL with demographic characteristics, biochemical indicators, and blood glucose levels.
Front Biosci (Landmark Ed)
December 2024
Department of Gynecology, Jincheng Hospital Affiliated to Changzhi Medical College, Jincheng People's Hospital, 048026 Jincheng, Shanxi, China.
Background: Endometriosis is a complicated and enigmatic disease that significantly diminishes the quality of life for women affected by this condition. Increased levels of human telomerase reverse transcriptase () mRNA and telomerase activity have been found in the endometrium of these patients. However, the precise function of TERT in endometriosis and the associated biological mechanisms remain poorly understood.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!