PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Chick Embryo”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

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

At least 73 records · Page 4Linked to original sources
PubMed1979

Oligo(A) and double-stranded segments in polyadenylated and non-polyadenylated RNA from cytoplasm and nuclei of chick embryo.

Chick embryonic RNA was fractionated by affinity chromatography on oligo(dT)-cellulose and poly(U)-Sepharose into three classes: poly(A)+RNA containing poly(A) segments of 100 and more residues, poly(A)-oligo(A)+RNA containing oligo(A) segments of about 25 residues, and poly(A)-oligo(A)-RNA which bound to neither of the beds used and which contained double-stranded segments of 300 and more base pairs. These three classes of RNA were found in cytoplasmic as well as in heterogeneous nuclear RNA. Double-stranded segments in hnRNA, unlike those in cytoplasmic RNA, were intermolecular in nature; this may explain the occurrence of "giant" molecules in hnRNA.

Animals↗
PubMed1980

Physical and immunochemical characterization of proteoglycans synthesized during chondrogenesis in the chick embryo.

Chick limb buds from 4- to 7-day-old embryos and sterna from 14-day-old embryos were labeled with [35S]sulfate, and the sulfated proteoglycans (PGS) were extracted either with associative (0.5 M guanidine . HCl) or dissociative (4.0 M guanidine . HCl) solvents. The existence of several populations of PGS is revealed in each age group when the limb extracts are analyzed on sucrose density gradients under dissociative conditions. The major component of 7-day limbs has a faster sedimentation rate than does that of 4-day limb buds. These major components of 4- and 7-day extracts chromatograph in the void volume of a controlled-pore glass (CPG) 1400 column. They differ from each other immunologically. The CPG 1400 void volume material from 4-day limb mesenchyme (PGS(LM)-I) shows no cross-reactivity with antiserum against PGS from juvenile cartilage (A1-D1-1400 V0). In contrast, the CPG 1400 void volume material from 7-day limbs, which contain cartilage [PGS(LC)-I], gave a cross-reaction of 70%. When PGS(LM)-I is chromatographed on CPG 2500, 45% of the labeled material chromatographs in the void volume. When PGS(LM)-I is sedimented in a cesium chloride gradient under dissociative conditions, it can be shown that the PGS in the bottom fraction (D1) has a monomer-aggregate relationship. In the absence of hyaluronic acid, this fraction is included on CPG 2500, whereas in the presence of hyaluronic acid it is excluded. Limb mesenchyme, therefore, synthesizes a PGS molecule which can interact with hyaluronic acid to form an aggregate. The endogenous material of a 4-day limb mesenchyme which causes the aggregation of PGS cannot be separated from PGS by chromatography on CPG 240 or 1400 under dissociative conditions. In contrast, the aggregating material from sterna can be separated from PGS under these conditions. These observations are interpreted to mean that the aggregating material of limb mesenchyme is larger than is that of cartilage.

Animals↗
PubMed1976

The origin, migration and morphology of the primordial germ cells in the chick embryo.

Chick primordial germ cells (PGCs) which separated from the "germinal crescent" entoderm in the period from stages 4 to 8 circulated mostly through the developing blood vessels from stage 10 onward and finally migrated into the gonad. The PGCs making their appearance up to this stage were generally spherical in profile, about 14 mum in diameter. Some of the PGCs in contrast, did not enter the blood vessels but remained in the tissue (mesenchyme) of the embryo proper (tissue PGCs) and possessed pseudopodial processes, suggesting their migration by means of amoeboid movements. The circulating PGCs emerged from blood vessels in the vicinity of developing gonads by three days (gonadal PGCs). The principal mechanism responsible for the subsequent migration of gonadal PGCs is assumed to be amoeboid movements as in the case of tissue PGCs. Notable amounts of PAS-positive glycogen were demonstrated in the cytoplasm of PGCs in all stages obsreved. They also contained yolk and lipids intracytoplasmically, the former dissipating in relatively early stages of development. Electron microscopic observation revealed the electron-opaque, "fragmented nucleolus" in the large nucleus (8 mum in diameter), which represented another prominent feature of chick PGCs. PGCs contained a well-developed Golgi complex and endoplasmic reticulum.

Aged↗
PubMed1993

Distribution of protein kinase C in the villi of duodenum of developing chick embryos and chicks: immunohistochemical studies at the light and electron microscopic levels.

We examined the immunohistochemical localization of protein kinase C (PKC) in chick embryonic and chick duodenal villi contained in cultured duodena using monoclonal antibodies that recognize types 1, 2 and 3 at the light and electron microscopic levels. In the light microscopic studies, staining with the type 2 and 3 PKC antibodies revealed immunoreactivities in the absorptive epithelial cells of the villi that approximated the time course after hatching, but was weak and partial just before the time of hatching. The epithelial cells of crypts seemed to lose their stain at all times. In the transmission electron microscopic studies, positive immunoreaction was found predominantly in the endoplasmic reticulum and nucleus, and also in the terminal web in the absorptive epithelial cells of villi. In the cultured duodenal fragments, a change in the distribution of PKC was observed on the sheet-like duodenal fragments and its immunoreaction was mainly seen on the basal side of absorptive cells. In contrast, no change in the staining of PKC was revealed on the ring-like duodenal fragments. These results suggested that PKC in the chick duodenal villi may be functionally related with the differentiation of absorptive epithelial cells and sensitive to changes in the cellular interactions of absorptive epithelial cells.

Animals↗
PubMedDate not supplied

[Respiration and glycolysis in the liver of developing chick embryos and chicks].

Oxygen uptake in liver slices remains constant between the 12th and the 17th days of embryonic development, being equal to that in 30-60-day chicks. During the transition from allantoic respiration to the pulmonary one, oxygen consumption decreases, the decrease being observed up to the end of embryonic period. After hatching, oxygen consumption increases 4-5-fold to the 6-7th and decreases up to the initial level at the 10th day. Respiration of mitochondria isolated from the liver and concentration of cytochromes in mitochondria remain constant. The value P/O is the lowest, whereas catalase activity is the highest during hatching. The intensity of anaerobic glycolysis changes similarly to that of respiration.

Aging↗