egg yolk is the most commonly used cryoprotective agent for sperm cryopreservation of several species.the objective of this experiment was to compare the effectiveness of egg yolk from four avian species(domestic chicken, duck, turkey and pigeon) on sperm quality following cryopreservation of the ram semen.ejaculates were collected, using an electroejaculator, from six fertile rams. samples wer...

Blood islands, the precursors of yolk sac blood vessels, contain primitive erythrocytes surrounded by a layer of endothelial cells. These structures differentiate from extra-embryonic mesodermal cells that underlie the visceral endoderm. Our previous studies have shown that Indian hedgehog (Ihh) is expressed in the visceral endoderm both in the visceral yolk sac in vivo and in embryonic stem (E...

This experiment was designed to compare powdered egg yolk with fresh egg yolk in an extender for cryopreservation of Zebu bull semen. Sperm motility, plasma membrane integrity and viability were assessed at different stages of cryopreservation (post-dilution, pre-freezing and post-thawing). Sperm plasma membrane integrity remained similar at all the stages of cryopreservation. Sperm motility an...

AIM The experiment was carried out to evaluate different external and internal egg quality traits and to figure out their mode of inheritance from a set of hierarchically classified data. MATERIALS AND METHODS The data collected from 548 progenies (1 egg from each progeny) of 282 dams mated to 47 sires (1 sire mated to 6 dams) of a White Leghorn flock were used in the present study. Phenotypi...

A yolk protein enzyme-linked immunosorbent assay (YP-ELISA) was developed for the predator Orius insidiosus (Say). The YP-ELISA is intended to assess reproductive response to dietary and other rearing conditions, and to assist in quality control and diet development for mass rearing. Hybridomas and monoclonal antibodies were produced against homogenates of eggs dissected from females. Hybridoma...

This study was conducted to assess the physical and morphological characteristics of fresh, pre-freeze and post-thaw black Bengal buck (Capra hircus) semen processed in Tris-egg yolk-citrate-fructose-glycerol (TEYCFG) extender containing 4 different concentrations (2.5, 5, 7.5 and 10%) of egg-yolk. Ejaculates were collected once a week for eight weeks from six mature bucks (48 ejaculates) using...

Background: The bovine yolk sac derives from visceral endoderm and its development occurs between days 18-23 of gestation. The study of this membrane is important for comparative data and has already been performed in rodents, sheep and in cattle, especially Bos taurus. In species Bos indicus the yolk sac has not quite been studied and is believed that there are morphological differences betwee...

Gastric yolk sac tumors are extremely rare and their prognosis is poor; most patients have widespread metastases at the time of diagnosis. The treatment of gastric yolk sac tumors consists of aggressive chemotherapy combined with radiotherapy and surgery. Here, we first report a case of gastric yolk sac tumor presenting as an early gastric cancer that was cured after a gastrectomy with lymphade...

RNA containing yolk nuclei from the surf clam Spisula solidissima have been studied with the light microscope and with the electron microscope. A variety of structures can be seen with both and a correlation can be made between bodies studied with the electron microscope and those studied with the light microscope. The electron microscope shows many of these structures to be composed of double ...