Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Pupa”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 235 records · Page 13Linked to original sources
PubMed1985

Ecdysteroids accelerate mitoses in accessory glands of beetle pupae.

During the 9-day pupal period of Tenebrio molitor (the mealworm beetle), the cells of the male accessory glands undergo divisions for 7 days. There are two maxima in the mitotic activity in the glands in vivo, one at 1 day and the other at 4 days. The latter peak coincides with the large surge of ecdysterone occurring in the pupal stage. By the use of in vitro culture techniques, it has been demonstrated that the first bout of mitosis in both glands proceeds in basal medium, while the second bout of mitosis requires a physiological level of ecdysterone. Ecdysone was less effective than ecdysterone. Sensitivity to ecdysterone did not change significantly between Day 1 and Day 4 of the pupal stage. The results are discussed in relation to the effects of ecdysterone on cell division in mesodermal and ectodermal derivatives.

Age Factors↗
PubMed1977

Cytodifferentiation in the accessory glands of Tenebrio molitor. III. Fine structure of the spermathecal accessory gland in the pupa.

To establish indices for studying the hormonal control of differentiation of the accessory reproductive glands of insects, the ultrastructural development of the spermathecal accessory gland (SAG) of female mealworm beetles has been analyzed. Over the 9 days between adult and pupal ecdysis, the SAG transforms from a stubby sac of columnar epithelium into an elongate cylindrical gland, lined with cuticle, and containing several distinct types of differentiated cells. The first phase of pupal differentiation is one of cell division and overall gland morphogenesis which lasts 3--4 days; at its close, two populations of cells can be distinguished. One of these populations will produce the cuticular ductules while the other will yield the three-cell secretory units or organules. In the second phase which lasts 2 days, the three cells of each organule become wrapped around one another and then the innermost puts out a pseudocilium and retracts within the next ensheathing cell. In the third phase which lasts 4 days, the cuticles of the axial duct, of the efferent ductule, of the vestibule upon which the ductules converge, and of the end apparatus, are deposited. The ciliary process degenerates, and after ecdysis, the secretory cells undergo peak differentiation.

Animals↗
PubMed1988

Maturation and degeneration of the fat body in the Drosophila larva and pupa as revealed by morphometric analysis.

Using morphometric and cytochemical techniques we have described changes taking place in the fat body cells during three different stages of development. The cell number remains constant at about 2200 cells during larval life and then decreases gradually and continuously throughout metamorphosis and the first 3 days of the adult stage until no more cells can be observed. Cell size increases rapidly during the larval period and decreases steadily during metamorphosis and adult stage. The size of the nuclei increases during the larval instars and decreases during the pupal interval. The change in nuclear size is correlated with the amount of DNA present throughout development implying the nuclear DNA is synthesized during the larval period and degraded gradually during metamorphosis. The cell size changes are due in large part to accumulation or loss of reserve substances: lipid droplets, glycogen deposits and protein granules. During metamorphosis the amount of lipid decreases slightly whereas glycogen experiences two loss cycles. The protein granules in the form of lysosomes continue to increase in amount during the first day of metamorphosis because of a short period of massive autophagy. Then the lysosomes decrease in amount throughout the remainder of metamorphosis. The lysosomes stain positively for lipofuscin.

Adipose Tissue↗