ABSTRACT
Typical centrioles are made of microtubules organized in ninefold symmetry. Most animal somatic cells have two centrioles for normal cell division and function. These centrioles originate from the zygote, but because the oocyte does not provide any centrioles, it is surprising that the zygotes of many animals are thought to inherit only one centriole from the sperm. Recently, in the sperm of Drosophila melanogaster, we discovered a second centriolar structure, the proximal centriole-like structure (PCL), which functions in the zygote. Whether the sperm of other insects has a second centriolar structure is unknown. Here, we characterized spermiogenesis in the red flour beetle, Tribolium castaneum Electron microscopy suggests that Tribolium has one microtubule-based centriole at the tip of the axoneme and a structure similar to the PCL, which lacks microtubules and lies in a cytoplasmic invagination of the nucleus. Immunostaining against the orthologue of the centriole/PCL protein, Ana1, also recognizes two centrioles near the nucleus during spermiogenesis: one that is microtubule-based at the tip of the axoneme, suggesting it is the centriole; and another that is more proximal and appears during early spermiogenesis, suggesting it is the PCL. Together, these findings suggest that Tribolium sperm has one microtubule-based centriole and one microtubule-lacking centriole.
Subject(s)
Centrioles/ultrastructure , Microtubules/ultrastructure , Spermatozoa/ultrastructure , Tribolium/ultrastructure , Animals , Centrioles/metabolism , Male , Microtubules/metabolism , Spermatids/metabolism , Spermatids/ultrastructure , Spermatogenesis , Spermatozoa/metabolism , Tribolium/physiologySubject(s)
Coronary Disease/prevention & control , Health Status Indicators , Health Surveys , Antihypertensive Agents/therapeutic use , Blood Pressure , Cholesterol, Dietary/analysis , Clinical Trials as Topic , Energy Intake , Follow-Up Studies , Humans , Hypertension/drug therapy , Lipoproteins/analysis , Smoking Prevention , Thiocyanates/bloodABSTRACT
Several studies conducted by the authors' group have shown that urinary steroid measurements are a valuable aid in differentiating the normal aging process, the pronounced aging associated with increased risk to coronary heart disease, and the deviations associated with myocardial infarction. Data are presented on 428 men in the age range of 30-70 years. The study design most effective in elucidating aging and disease patterns involves selection of subjects from a wide age range. Data on persons identified as clinically normal can be used to describe physiologic aging. Once this is determined, data on persons with disease can be used to identify abnormalities of aging associated with the clinical conditions studied. This approach offers a potential method for differentiating between aging effects and disease effects. The foregoing findings led to the development of an Index of Aging in males, based on combined serum lipid and urinary steroid values. This Index may be a means of differentiating between normal aging and the deviations seen in atherosclerosis and myocardial infarction. Current studies are directed toward extending these observations.
