The ovalbumin gene in chick oviduct nuclei or nucleosomes is digested preferentially by either DNase I or staphylococcal nuclease. Staphylococcal nuclease preferentially cuts between and within core particles of the oviduct ovalbumin gene; thus, the ovalbumin gene is more quickly degraded to mononucleosomes and the DNA within these monomers is digested to a nonhybridizable size significantly fa...

An estimate has been made of the time required for a population of spermatozoa capable of fertilizing the egg to be established in the oviducts of heifers mated early in oestrus. During a general or local anaesthetic, the caudal isthmus of the oviduct was ligated and sectioned 6, 8, 10 or 12 hr after mating. The proportion of eggs fertilized as judged 2-4 days later was very low if ligation was...

The purpose of this investigation was to study the expression of type X collagen in the hen's oviduct. Type X collagen is a short-chain collagen that is present in the fibers of eggshell membranes, and there is evidence to suggest that it contributes to structural integrity. In situ hybridization and Northern blot analysis were used to study the expression of this important matrix constituent. ...

Estrogen regulates reproductive behavior and drives the proliferation and differentiation of several cell types. These physiological functions of estrogen are mediated by estrogen receptors (ERs), and each ER isoform plays a distinct role. To clarify the molecular mechanism of estrogen action and to evaluate the effect of ERs on the secretion of ovalbumin (OVA) in pigeon oviduct epithelial cell...

The full-length pigeon ovalbumin (OVA) gene cDNA was cloned and sequenced by reverse transcription-polymerase chain reaction (RT-PCR) and rapid-amplification of cDNA ends. A 386-amino acid protein was predicted for the obtained sequence, which had 67% identity with the chicken protein. Similar to chicken OVA, the pigeon OVA gene is a non-inhibitory serine protease inhibitor. Quantitative PCR an...

Up to the present time the function and significance of the zona pellucida in the development of mammalian eggs has not been fully explained. Zona-free mouse eggs will develop in vitro from the 2-cell stage, or later, up to the blastocyst stage (Tarkowski, 1961; Mintz, 1962; Gwatkin, 1963). Single blastomeres isolated at the 2-cell (Mulnard, 1965), 4and 8-cell stage (Tarkowski & Wróblewska, 196...

Up to the present time the function and significance of the zona pellucida in the development of mammalian eggs has not been fully explained. Zona-free mouse eggs will develop in vitro from the 2-cell stage, or later, up to the blastocyst stage (Tarkowski, 1961; Mintz, 1962; Gwatkin, 1963). Single blastomeres isolated at the 2-cell (Mulnard, 1965), 4and 8-cell stage (Tarkowski & Wróblewska, 196...

We present evidence that conalbumin and transferrin, synthesized in chick oviduct and liver, respectively, are products of the same gene, but the gene is regulated differently in the two tissues. Conalbumin mRNA was purified 500-fold from hen oviduct by a combination of immunoprecipitation of polysomes, oligo(dT) chromatography, and sucrose gradient centrifugation. A cDNA complementary to conal...

An optoelectronic instrument, developed to record the muscular activity of the oviduct was used to monitor the effects of oxytocin on oviductal contractions in intact ewes. The transducer consisted of one light emitting diode opposed by two phototransistors and their associated lead wires molded into a "C" shaped cuff in a clear orthodontic resin. The resulting optoelectronic transducer was att...