SpermatocytesSpermatogenesisSpermatidsTestisMeiosisSertoli CellsPachytene StageSpermatogoniaSpermatozoaSeminiferous TubulesSeminiferous EpitheliumMeiotic Prophase ISynaptonemal ComplexProphaseChromosome PairingBlood-Testis BarrierInfertility, MaleGerm CellsChromosomesSperm CountDipteraLeydig CellsMetaphaseSex ChromosomesCell DivisionY ChromosomeFertilityMolecular Sequence DataTriethylenemelamineImmunohistochemistrySalamandridaeGene Expression Regulation, DevelopmentalIn Situ HybridizationRNA, MessengerDrosophila ProteinsOligospermiaEpididymisMitosisOrthopteraSex ChromatinSpindle ApparatusNuclear ProteinsMicroscopy, ElectronCytokinesisBase SequenceGrasshoppersCell NucleusOrgan SizeCell DifferentiationAnaphaseOncogene Proteins v-mosDrosophila melanogasterCryptorchidismSexual MaturationAmino Acid SequenceCyclin A1HistonesRats, Sprague-DawleyTestosteroneDrosophilaMutationEthylene GlycolsCell Cycle ProteinsMicrotubulesAcrosomeMicroscopy, Phase-ContrastMice, Inbred C57BLGene ExpressionContraceptive Agents, MaleGravity, AlteredBlotting, NorthernCells, CulturedHaploidyIn Situ Nick-End LabelingTesticular DiseasesTime FactorsApoptosisStem CellsAndrogen-Binding Protein