Tracking wireworm burrowing behaviour in soil over time using 3D X-ray computed tomography.

Background: Wireworms (larvae of the click beetle, Elateridae) are a significant agricultural pest, causing crop damage and reducing yields globally. Owing to the complex nature and opacity of the soil environment, research to investigate wireworm behaviour in situ has been scarce. X-ray computed tomography (CT) has previously been demonstrated as a powerful tool to independently visualise the 3D root system architecture, macroinvertebrate movement and distribution of burrow systems in soil, but not simultaneously within the same sample.

Genital and nongenital teratogenesis of prenatal progestogen therapy: the effects of 17 alpha-hydroxyprogesterone caproate on embryonic and fetal development and endochondral ossification in the C57B1/6J mouse.

Objective: The current study assesses the effects of 17 alpha-hydroxyprogesterone caproate on embryo-fetal development, with a particular focus placed on intrauterine endochondral bone development and growth.

Study Design: Primigravid C57 BI/6J mice were administered 17 alpha-hydroxyprogesterone caproate by means of subdermal pellets designed to deliver doses of 0.5, 5.

Effect of gestational sex steroid exposure on limb development and endochondral ossification in the pregnant C57Bl/6J mouse: I. Medroxyprogesterone acetate.

Although data supporting the teratogenic potential of intrauterine progestin exposure is lacking, concern persists among some individuals within the scientific community that these drugs have the potential for nongenital teratogenesis, especially with regard to limb reduction defects. Our laboratory has been interested in the ontogeny of steroid receptors in the developing embryo and in the role of steroid-receptor interactions in limb development, particularly the process of endochondral ossification. Since limb reduction defects can be produced from abnormal processes that are operative during organogenesis or during midgestation (vascular disruption) we have designed an animal study whereby embryos were exposed to sex steroids throughout organogenesis and fetal development.

Characterization of cytosolic glucocorticoid receptor of fetal rat epiphyseal chondrocytes.

The cytosolic glucocorticoid receptor of 21st gestational day rat epiphyseal chondrocytes has been evaluated. The receptor, a single class of glucocorticoid binding component approached saturation, utilizing [3H]triamcinolone acetonide ([3H]TA) as the radiolabeled ligand, at approximately 1.8-2.

X-chromosome inactivation in the human cytotrophoblast.

Preferential paternal X-chromosome inactivation occurs in the cell lineages that differentiate first within the female rodent blastula (trophectoderm and extraembryonic endoderm). The present studies were designed to test the nature of X-chromosome inactivation (XCI) in the earliest differentiating cell lineage of the human placenta, the cytotrophoblast. Using glucose-6-phosphate-dehydrogenase (G6PD) polymorphisms as a marker system, term placentae were obtained from 13 female heterozygotes where parental allelic contributions could be determined.

Carrier-mediated uptake of hexoses by the rat visceral yolk sac.

The rat visceral yolk sac is shown to possess a sodium-independent, phloretin-sensitive, and phlorizin- and ouabain-insensitive transport system for hexoses. The rate of uptake of (3H)2-deoxy-D-glucose was measured in vitro and shown to be greatest on the 12th day, decreasing progressively with increasing gestational age up to the 20th day. Little uptake of 3-O-methyl-D-glucose, alpha-methylglucoside or L-glucose occurred.

Indirect effect of x-irradiation on embryonic development: utilization of high doses of maternal irradiation on the first day of gestation.

Two hundred and eighteen female rats were utilized in this study to evaluate the indirect effect of maternal x-irradiation on embryonic development and survival. There were two control groups and ten experimental groups receiving 0, 60, 150, 275, or 400 R on the afternoon of the first day. The use of special shielding devices permitted irradiation of either the mother or the zygote.