The Drosophila melanogaster male germ cells are sensitive to the recombinogenic activity of chemical compounds. In our experiments, we have employed four recessive markers located on the 2nd chromosome: dumpy (dp, 13.0), black (b, 48.5), cinnabar (cn, 57.5), and brown (bw, 104.5); b and cn flank the centromere. Three-day-old larvae, heterozygous for these markers, were treated chronically by oral administration with the test compounds. The chemicals already shown to be positive or negative in the assay systems to test chemical agents in D. melanogaster are three carcinogens (4-nitroquinoline N-oxide, hydroxylamine HCl, and acrylamide), four herbicides (maleic hydrazide, alachlor, trifluralin, and amitrol), and three insecticides (endrin, piperonyl butoxide, and allethrin). In our study, some compounds induced recombinogenic effects in Drosophila premeiotic male germ cells, and comparison of our results with those reported in the literature with the Drosophila wing somatic mutation and recombination assay showed that the somatic cells and the germinal cells have a differential response to the defined compounds.
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http://dx.doi.org/10.1016/j.ecoenv.2005.05.022 | DOI Listing |
Adv Exp Med Biol
January 2025
METU MEMS Center, Ankara, Turkey.
Male factor accounts for 30-50% of infertility cases and may occur due to congenital anomalies or acquired disorders. In such infertility cases where a limited number of mature sperm is produced, a solution is offered to patients with ART applications; however, these methods are inadequate in patients with germ cell aplasia due to damaged microenvironment. Since monolayer cell culture and static culture conditions do not provide the physical conditions of the 3D microenvironment, they have a limited effect on ensuring the execution of in vitro spermatogenesis properly.
View Article and Find Full Text PDFCommun Biol
January 2025
Université Paris Cité, CNRS, Inserm, Institut Cochin, F-75014, Paris, France.
The H3K79 methyltransferase DOT1L is essential for multiple aspects of mammalian development where it has been shown to regulate gene expression. Here, by producing and integrating epigenomic and spike-in RNA-seq data, we decipher the molecular role of DOT1L during mouse spermatogenesis and show that it has opposite effects on gene expression depending on chromatin environment. On one hand, DOT1L represses autosomal genes that are devoid of H3K79me2 at their bodies and located in H3K27me3-rich/H3K27ac-poor environments.
View Article and Find Full Text PDFCurr Top Dev Biol
January 2025
Université de Strasbourg, IGBMC UMR 7104, Illkirch, France; CNRS, UMR 7104, Illkirch, France; Inserm, UMR-S 1258, Illkirch, France; IGBMC, Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France. Electronic address:
In mammals, differentiation of germ cells is crucial for sexual reproduction, involving complex signaling pathways and environmental cues defined by the somatic cells of the gonads. This review examines the long-standing model positing that all-trans retinoic acid (ATRA) acts as a meiosis-inducing substance (MIS) in the fetal ovary by inducing expression of STRA8 in female germ cells, while CYP26B1 serves as a meiosis-preventing substance (MPS) in the fetal testis by degrading ATRA and preventing STRA8 expression in the male germ cells until postnatal development. Recent genetic studies in the mouse challenge this paradigm, revealing that meiosis initiation in female germ cells can occur independently of ATRA signaling, with key roles played by other intrinsic factors like DAZL and DMRT1, and extrinsic signals such as BMPs and vitamin C.
View Article and Find Full Text PDFCurr Top Dev Biol
January 2025
School of Molecular Biosciences, Washington State University, Pullman, Washington, United States. Electronic address:
For mammalian spermatogenesis to proceed normally, it is essential that the population of testicular progenitor cells, A undifferentiated spermatogonia (A), undergoes differentiation during the A to A1 transition that occurs at the onset of spermatogenesis. The commitment of the A population to differentiation and leaving a quiescent, stem-like state gives rise to all the spermatozoa produced across the lifespan of an individual, and ultimately determines male fertility. The action of all-trans retinoic acid (atRA) on the A population is the determining factor that induces this change.
View Article and Find Full Text PDFBMC Microbiol
January 2025
State Key Laboratory of Oral Diseases, West China School of Stomatology, National Clinical Research Center for Oral Diseases, Sichuan University, Chengdu, China.
Background: Streptococcus mutans is recognized as a key pathogen responsible for the development of dental caries. With the advancement of research on dental caries, the understanding of its pathogenic mechanism has gradually shifted from the theory of a single pathogenic bacterium to the theory of oral microecological imbalance. Acidogenic and aciduric microbial species are also recognized to participate in the initiation and progression of dental caries.
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