The base sequence analysis of a Xenopus laevis ribosomal DNA repeat (7) has been extended to cover almost the entire non-transcribed and external transcribed spacer. A compilation of these sequences is presented. All the repetitive and non-repetitive sequence elements of the spacer are identified and their evolution discussed. Comparison of the X.laevis and S.cerevisiae (25,26) ribosomal DNAs shows about 80% sequence conservation in the 18S gene but no sequence conservation, from the available data, in the external transcribed spacer. The sequence coding for the 3' terminus of the X.laevis 40S ribosomal precursor RNA is presented and its structural features analyzed.
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http://dx.doi.org/10.1093/nar/8.3.467 | DOI Listing |
Elife
January 2025
Calcium Signaling Group, Research Department, Weill Cornell Medicine Qatar, Education City, Qatar Foundation, Doha, Qatar.
The steroid hormone progesterone (P4) regulates multiple aspects of reproductive and metabolic physiology. Classical P4 signaling operates through nuclear receptors that regulate transcription. In addition, P4 signals through membrane P4 receptors (mPRs) in a rapid nongenomic modality.
View Article and Find Full Text PDFExpert Opin Drug Discov
January 2025
Division of Genetics and Genomics, Department of Pediatrics, Boston Children's Hospital, Boston, MA, USA.
Introduction: Kabuki Syndrome (KS) is a rare genetic disorder characterized by distinctive facial features, intellectual disability, and multiple congenital anomalies. It is caused by pathogenic variants in the and genes. Despite its significant disease burden, there are currently no approved therapies for KS, highlighting the need for advanced research and therapeutic development.
View Article and Find Full Text PDFRegul Toxicol Pharmacol
January 2025
Health and Environmental Sciences Institute, Washington, DC, USA.
The amphibian metamorphosis assay (AMA) is an in vivo screen to assess potential interactions of chemicals with the amphibian thyroid system. Tadpoles are exposed for 21-days, then assessed for development and growth after 7 days and at test termination. This paper presents data from studies performed to satisfy test orders from the US EPA's Endocrine Disruptor Screening Program.
View Article and Find Full Text PDFThe brain and spinal cord originate from a neural tube that is preceded by a flat structure known as the neural plate during early embryogenesis. In humans, failure of the neural plate to convert into a tube by the fourth week of pregnancy leads to neural tube defects (NTDs), birth defects with serious neurological consequences. The signaling mechanisms governing the process of neural tube morphogenesis are unclear.
View Article and Find Full Text PDFPigment Cell Melanoma Res
January 2025
Department of Cell Biology and Anatomy, Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada.
Circadian regulation of skin pigmentation is essential for thermoregulation, ultraviolet (UV) protection, and synchronization of skin cell renewal. This regulation involves both cell-autonomous photic responses and non-cell-autonomous hormonal control, particularly through melatonin produced in a light-sensitive manner. Photosensitive opsins, cryptochromes, and melatonin regulate circadian rhythms in skin pigment cells.
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