Exogenous DNA Uptake of Boar Spermatozoa by a Magnetic Nanoparticle Vector System

The sperm‐mediated gene transfer method is applicable to transgenesis in many species that use spermatozoa for reproduction recently, which has been shown various results. In the current study, we show that transgenic porcine embryos can be efficiently produced by employing a simple transfection method that uses magnetic nanoparticles (MNPs). The complexes formed between plasmid DNA and MNPs were bounded on ejaculated boar spermatozoa at a higher efficiency compared to methods using DNA alone or lipofection. Using confocal microscopy, rhodamine fluorophore‐labelled MNPs were detected on external surfaces of the spermatozoa membrane, which were bounded on zona pellucida of in vitro maturated oocyte during in vitro fertilization. Electron microscopy revealed that clusters of MNPs were detected in inside of plasma membrane and nucleus of the spermatozoa head. Additionally, we found that magnetofected boar spermatozoa could be fertilized with oocytes in vitro and that the resulting gene of green fluorescent protein was detected in fertilized eggs by genomic PCR analysis. Taken together, these results suggest that MNPs can be used to efficiently introduce a transgene into embryo via spermatozoa.     

Effects of homogenization pressure and stabilizers on some physical characteristics of a beverage prepared from partially defatted, roasted peanuts

A low-fat beverage with roasted peanut flavor was developed from peanuts. The potential milk substitute contained 11.8% total solids, 2.0% fat and 3.7% protein, and was whitish orange-yellow in color. The effects of stabilizing additives and homogenization pressure (13.8×10⁶ Pa or 41.4×10⁶ Pa) on selected physical characteristics were determined. Suspension stability was improved by addition of carrageenan [Benlacta CM61-B (CM), 0.02–0.04%] or a hydrogenated mono- and diglyceride [Emuldan HV52K (HV, 0.2–0.4%)]. Homogenizing at 41.4×10⁶ Pa increased viscosity of all samples except that of the controls but did not improve the suspension stability (top:bottom solids) of the beverage. The most viscous formulations (17.5±0.95 cps) were those containing 0.04% CM. Treatments yielding the best combination, compared to cow's milk values, of high suspension stability (0.5±0.03, where 1.0=maximum stability) and low viscosity (3.7±0.89 cps) were those containing 0.2% HV which were homogenized at 13.8×10⁶ Pa.     

Bone ossification and carcass characteristics of wethers given silastic implants containing estradiol

Administration of growth promotants with estrogenic activity via hastening closure of the growth plate could have an economic impact on lambs because closure results in ovine carcasses being classified as yearlings. Twelve wether lambs approximately 12 mo old were given silastic implants filled with estradiol-17 beta and allotted randomly to be slaughtered 30, 60, 90, or 220 d after implantation to determine time of growth plate closure in relation to date of implanting. Seven comparable wethers not implanted served as controls. Four wethers implanted at 2 mo of age and slaughtered 220 d later also were included. Implanted wethers had serum concentrations of estradiol averaging 13.9 pg/ml over the 220-d implant period; controls averaged 2.7 pg/ml. Estradiol implants increased carcass maturity scores but fat deposition was not altered. Growth plate widths decreased (P less than .05) as wethers grew older and implants were in place for longer periods of time. Metacarpal growth plates in 12-mo-old lambs were completely ossified 220 d after implanting, but control wethers and wethers implanted at 2 mo maintained growth plate widths. Neither metacarpal nor metatarsal bone lengths differed (P less than .05) between control and implanted wethers. Growth plate ossification was not complete until 570 d of age in implanted lambs, even though bone length had stopped increasing by 408 d. Therefore, even though estradiol and other growth stimulants with estrogenic activity increase rate of ossification of the metacarpal growth plate, bone length or mature size is not limited.(ABSTRACT TRUNCATED AT 250 WORDS)     

Microvascular circulation of the ascending colon in horses

Microvascular circulation of the ascending colon in healthy horses was studied using microangiography, light microscopy, and scanning electron microscopy. The pelvic flexure with 30 cm of ventral and dorsal colon attached was removed from 14 adult horses immediately after horses were euthanatized. The lumen was flushed with warm water, and this section of the ascending colon was placed in a 37-C bath of isotonic NaCl. In sections from 8 horses, colic vessels were perfused with a radio-opaque medium for microangiography. After angiographic evaluation, tissue sections were prepared for light microscopic observation, using standard histologic methods. In sections from 6 horses, injection replicas were made by perfusing the vessels with 2 types of plastics. The results of microangiography, light microscopy, and scanning electron microscopy of vascular replicas were correlated, providing a comprehensive documentation of the microvasculature of the ascending colon at the pelvic flexure. Arteries branched from mesenteric colic vessels approximately every 2 cm toward the colonic tissue. Immediately after branching, arterial vessels formed an anastomotic plexus, the colonic rete. However, each branch from the colic vessel eventually continued into the colonic tissue. A second set of vessels originated from the colonic tissue. A second set of vessels originated from the colonic rete and supplied the mesenteric lymph nodes. Arterial vessels penetrated the tunica muscularis into the submucosa 3 to 4 cm toward the antimesenteric border forming a submucosal vascular network. From the submucosal arterioles, branching took place at right angles to supply the mucosal capillaries. Capillaries surrounded the colonic glands and anastomosed at the luminal surface, forming a superficial luminal honeycomb-appearing vascular plexus.(ABSTRACT TRUNCATED AT 250 WORDS)     

Osmotic stress in red blood cells from beagles with hemolytic anemia.

Red blood cell populations separated by density centrifugation were compared in a dynamic assay of osmotic stress. Red blood cells from Beagles genotypically normal and nonanemic (nonaffected), Beagles with inherited hemolytic anemia (anemic), and Beagles presumed to be carriers of the anemia trait (trait carriers) were examined for rate and extent of swelling after exposure to the ionophore A23187 in a medium containing calcium and potassium chloride. Comparisons were made between RBC populations separated on the basis of density. Significant differences were observed in the rates of cell swelling in RBC populations separated by density between nonaffected and anemic Beagles. The response of RBC from Beagles presumed to carry the anemia trait was similar to that of RBC from nonaffected dogs. One phenotypic expression of this inherited abnormality of RBC in Beagles was an accelerated rate of RBC swelling under osmotic stress, and this swelling response diminished with increasing RBC density.     

Shipboard geophysical indications of asymmetry and melt production beneath the east pacific rise near the MELT experiment

Near the Mantle Electromagnetic and Tomography (MELT) Experiment, seamounts form and off-axis lava flows occur in a zone that extends farther to the west of the East Pacific Rise than to the east, indicating a broad, asymmetric region of melt production. More seamounts, slower subsidence, and less dense mantle on the western flank suggest transport of hotter mantle toward the axis from the west. Variations in axial ridge shape, axial magma chamber continuity, off-axis volcanism, and apparent mantle density indicate that upwelling is probably faster and more melt is produced beneath 17 degrees15'S than beneath 15 degrees55'S. Recent volcanism occurs above mantle with the lowest seismic velocities.     

Comparative Development of Embryonic Age by Organogenesis in Domestic Dogs and Cats

The precise determination of the embryonic chronology is very important in reproductive biotechnologies, especially in estimating embryonic age. Thus, there is a need for greater knowledge and standardization for determining the chronology of embryonic development and functional morphology. We describe aspects of embryonic development in two domestic carnivores to add knowledge about organ peculiarities and for application in veterinary practice, in prenatal development and in the biotechnology fields. We found that the development of differential characteristics of embryonic organs occurs in the first trimester of pregnancy for both species. Thus, using the combination of the crown‐rump length, macroscopic analysis and optical microscopy, it is possible to predict gestational age more precisely in animals that lack a defined breed and establish an embryonic pattern.     

Up‐Regulation of Insulin‐Like Growth Factor I and Uteroglobin in In Vivo‐Developed Parthenogenetic Embryos

Parthenote embryos are being considered as an alternative source of embryonic stem cells. However, as there is still a dearth of knowledge of this kind of embryos, a better understanding of their biology is needed for their application. In this work, we studied the differences and similarities between parthenotes and normal embryos at the blastocyst stage in vivo developed. We analysed the expression of factor OCT‐4, vascular endothelial growth factor (VEGF), insulin‐like growth factor I (IGF‐I) and uteroglobin (UG) by real‐time PCR. To do so, oocytes were recovered and after activation procedure were transferred by ventral middle laparoscopy to receptive does to undergo completely in vivo development. Does were slaughtered 6 days post‐ovulation induction, and parthenote and normal embryos were recovered for mRNA expression analysis. Our results reported that parthenotes and normal embryos showed similar mRNA expression for OCT‐4 and VEGF. However, IGF‐I and UG showed to be over‐expressed in parthenote embryos. Thus, our study highlights that despite the in vivo development of parthenotes, they still seem to have an altered expression and, therefore, to be different to normal embryos. The altered expression pattern of parthenote embryos suggests that these embryos should be studied carefully before future application.