Refrigeration to limit bacterial multiplication is a critical aspect of efforts to control the transmission of Salmonella enterica serovar Enteritidis (SE) to consumers of contaminated eggs. Although the nutrient-rich yolk interior is an uncommon location for SE contamination in freshly laid, naturally contaminated eggs, migration across the vitelline membrane could lead to rapid bacterial mult...

The present studies were performed to further characterize a mouse yolk sac protein which is similar or identical to the vitamin D-dependent intestinal calcium-binding protein (CaBP). Yolk sac protein and purified rat intestinal CaBP displayed full identity upon immunodiffusion (Ouchterlony) using antiserum to the rat intestinal CaBP. Immunoreactive CaBP in yolk sac homogenates eluted from gel ...

A study was conducted to determine the effect of feeding high concentrations of corn distillers dried grains with solubles (DDGS) on egg production and the internal quality of eggs from laying hens. Four diets were formulated to contain 0, 17, 35, or 50% corn DDGS. A total of two hundred forty 54-wk-old Single-Comb White Leghorn laying hens were randomly allotted to 2 birds per cage with 3 cons...

The mechanisms involved in the induction of yolk sac mesoderm into blood islands and the role of visceral endoderm and mesoderm cells in regulating the restricted differentiation and proliferation of hematopoietic cells in the yolk sac remain largely unexplored. To better define the role of murine yolk sac microenvironment cells in supporting hematopoiesis, we established cell lines from day-9....

The yolk, defined by McKelvey as the smallest ball intersecting all median hyperplanes, is a key concept in the Euclidean spatial model of voting. Koehler conjectured that the yolk radius of a random sample from a uniform distribution on a square tends to zero. The following sharper and more general results are proved here: Let the population be a random sample from a probability measure μ on <...

OBJECTIVE To review the process of blood-cell formation in the murine and human yolk sac. DATA SOURCES Most articles were selected from the PubMed database. DATA SYNTHESIS The yolk sac is the first site of blood-cell production during murine and human ontogeny. Primitive erythroid cells originate in the yolk sac and complete their maturation, including enucleation, in the bloodstream. Thoug...

The amniote egg was a key innovation in vertebrate evolution because it supports an independent existence in terrestrial environments. The egg is provisioned with yolk, and development depends on the yolk sac for the mobilization of nutrients. We have examined the yolk sac of the corn snake Pantherophis guttatus by the dissection of living eggs. In contrast to the familiar fluid-filled sac of b...

In the chicken, maternal IgG is deposited in the oocyte yolk and subsequently transported intact by the foetal chick yolk sac into the chick circulation. Such transport appears to require a specific membrane-localized IgG receptor. Using the assay of 125I-yolk IgG binding, we have investigated the existence and properties of such receptors in yolk sac tissue disks. We find that: (1) There are s...