What's the difference between meiosis and spermatogenesis?

Meiosis


Definition:

  • (n.) Diminution; a species of hyperbole, representing a thing as being less than it really is.

Example Sentences:

  • (1) To this end, a meiosis-defective mating-type mutation was used as a marker for the plus segment, by taking advantage of its suppressibility by a nonsense suppressor.
  • (2) When multiple probes were informative, the meiotic exchange points for each meiosis were located in individual families.
  • (3) This observation suggests that testosterone acts to inhibit meiosis at a site beyond the function of the puromycin-sensitive proteins or that testosterone causes a reduction in the turnover rate of these proteins.
  • (4) Commitment to meiosis occurs during the prezygotene interval at about the time when S-phase replication is completed.
  • (5) Meiosis is too complex to have arisen at once full blown and a stepwise scheme is proposed for its evolution, where each step is believed to have provided an immediate selective advantage: (1) The first step in this tentative sequence is the development of a haploidization process by means of a rapid series of mitotic non-disjunctions, turned on under conditions where haploidy is favored.
  • (6) Recently, cDNA clones encoding several bovine CKI isoforms have been sequenced that show high sequence identity to the HRR25 gene product of the budding yeast Saccharomyces cerevisiae; HRR25 is required for normal cellular growth, nuclear segregation, DNA repair, and meiosis.
  • (7) They proceed through meiosis normally, as judged by the occurrence of meiotic recombination, the production of haploid nuclei, and the formation of multinucleate cells visible after Giemsa staining.
  • (8) In continuation of the research on male human meiosis within the study of pachytene bivalents, results from the analysis of 125 cells are presented.
  • (9) The absence of these mRNAs in mitosis and their disappearance at 4 hr and later in meiosis suggest that the rec7 and rec8 gene products may be involved primarily in the early steps of meiotic recombination in S. pombe.
  • (10) This trisomy arose through aberrant segregation of translocation chromosome during meiosis in the patient's mother, who is a balanced heterozygote for a complex translocation involving chromosomes 9, 21 and 22.
  • (11) Chemicals were injected into mice at the MI (meiosis I) stage or 3 hours before the MI stage in order to examine their toxicity.
  • (12) In the immunogold staining assay a post-fixation and nuclear staining procedure was developed which allowed identification of isolated germ cells, revealing clearly, for all seven MAbs, that the determinants were expressed on germ cells but not on somatic cells and, for WCS 7, 11 and 12 only, that the determinants first appeared on small spermatogonia prior to meiosis.
  • (13) A 'small' CG-free area of the cortex, with prominent cytoplasmic protrusions, appeared twice during the progression of meiosis.
  • (14) An attractive explanation for these results is that long tandem arrays of simple repeated sequences are generated at high frequency throughout the genome and that they are retained for a longer time on the Y chromosome due to the absence of homologous pairing at meiosis.
  • (15) Expression of one of the three genes was found to be limited to a single cell type during the 5-6 day period from late meiosis to immature pollen formation.
  • (16) Analysis of RNA from different developmental stages and from enriched populations of spermatogenic cells revealed that this gene is expressed during the prophase stage of meiosis.
  • (17) In fission yeast the ability to undergo meiosis and sporulation is conferred by the matP+ and matM+ genes of the mating-type locus.
  • (18) The binding of in vivo labeled RNA to the corresponding DNAs increased 3- to 12-fold at the time of meiosis I, in parallel with the accumulation of the SPR transcripts.
  • (19) It was concluded that meiosis and spore formation in Saccharomycopsis lipolytica seem to represent parallel and coordinated processes which generally resemble those recorded for Saccharomyces cerevisiae and Hansenula species.
  • (20) Neither meiosis nor mutagenesis increased the revertant frequency, nor did incubation at elevated temperatures lower it.

Spermatogenesis


Definition:

  • (n.) The development of the spermatozoids.

Example Sentences:

  • (1) An effective gonadal shield should reduce the gonadal dose to a level low enough to preserve spermatogenesis in most patients.
  • (2) The findings support our earlier suggestion that the kinetics of spermatogenesis in the quail are fundamentally similar to the pattern which has been described for mammals.
  • (3) Combined with histological analysis, these results suggest a more rapid recovery of normal spermatogenesis after physical insult with LAC treatment.
  • (4) The effect of the mutation for white belly spot controlled by the dominant gene W on spermatogenesis in mice was examined by experimental cryptorchidism and its surgical reversal.
  • (5) After 35 and 43 days, spermatogenesis was complete in 99.6% of the tubular cross sections, and most tubular cross sections were in stages IV-VII of the cycle of the seminiferous epithelium.
  • (6) The morphological process of spermatogenesis is largely unaffected and motile sperm are produced, but meiocyte aneuploidy is common.
  • (7) These results demonstrate that administration of a GnRH antagonist in the presence of constant serum T levels does not induce consistent azoospermia, and that the supporting effects of T on spermatogenesis cannot be explained exclusively on the basis of the testicular androgen concentrations.
  • (8) These injections suppressed peripheral FSH levels to 6% of the control values, suggesting that FSH might be the modulator of the effects on spermatogenesis.
  • (9) It is concluded that this new method of administration may have practical and pharmacokinetic advantages for the purpose of reversible inhibition of spermatogenesis.
  • (10) Whether this mechanism is thermoregulatory for the normal spermatogenesis cannot be inferred from the present work.
  • (11) The nuclei were isolated from boar spermatid or sperm cells at three distinct stages of spermatogenesis: just before the completion of a maturation process in the testis (late spermatid), immediately after a subsequent transformation into spermatozoa (caput spermatozoon), and after full maturation (cauda spermatozoon).
  • (12) Considering that chromatin reorganizations during spermatogenesis may be directly or indirectly related to changes of the nuclear lamina we have decided to further investigate lamin expression during this process.
  • (13) In addition, there is significantly less germ cell production from the primary spermatocyte stage of spermatogenesis onwards and the total number of Sertoli cells observed is less.
  • (14) An alternative explanation, that there may be a pre-existing defect in spermatogenesis, was tested in 20 post-pubertal males with acute torsion.
  • (15) In this study, we document the presence of significant mRNA levels for 5 different PKA subunits (RI alpha, RI beta, RII alpha, RII beta, and C alpha) in germ cells and demonstrate differential expression patterns for these subunits during spermatogenesis.
  • (16) While the results reflect antiandrogenic and antispermatogenic action of V. rosea, the selective retention of the spermatogonia provides scope for the much desired revival of spermatogenesis on cessation of the treatment.
  • (17) The solvent alone, hydroxypropyl cellulose, had some inhibitory effect on spermatogenesis.
  • (18) The regulation of cellular growth is essential in the developing testis and is required for the maintenance of spermatogenesis in the adult testis.
  • (19) Analysis of data on the influence of different metals (cadmium, cobalt, molybdenum) on the Drosophila melanogaster cells has revealed a considerable genotoxic effect of cadmium salts which manifests in the high percentage of cells elimination at the early stages of spermatogenesis--the premeiotic cells.
  • (20) Changes in the mode of DNA packaging in nuclei during spermatogenesis were studied by measuring of the fluorescence anisotropy decay of an ethidium dye intercalated in the DNA in whole nuclei.

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