Use of an androgenized mare as an aid in detection of estrus in mares

A study was conducted over a 2-mo period to compare estrus detection results obtained using an androgenized teaser mare with those obtained with a stallion, using the same group of 10 normally cyclic mares. The teaser mare was androgenized by administration of boldenone undecylenate (500 mg i.m. every 1 to 2 wk), and allowed to run loose with the mare group. Estrus was determined by observation of the group for a 30-min period daily. In the second month of the experiment, a marking harness was used on the androgenized mare to help detect mares mounted when in estrus. Estrous periods detected by each teasing method were 1) first month: stallion, 18; androgenized mare, 5; 2) second month: stallion, 16; androgenized mare, 9. There were no estrous periods detected by the androgenized mare that were not also detected by the stallion. Under these conditions, the androgenized mare was not an adequate estrus detection aid. Also discussed are the successful results of an independent trial on a breeding farm using an androgenized mare as an estrus detection aid.     

Are fluorescent bodies of Y-spermatozoa detectable in common with mammalan species?

An attempt was made to detect the fluorescent bodies (F-body), using Quinacrine mustard (Q-M) staining in the spermatozoa from eight mammalian species (human, bull, boar, dog, rabbit, rat, mouse, and mastomys) as well as in the cock (used as negative control). Sperm suspension, prepared after rinsing by repeated centrifugation with phosphate buffered saline (PBS), was either stained with Q-M for 24 h or treated with protease and then stained with Q-M for 60 min. The final concentration of Q-M in the mixed staining sperm suspension was 0.025 mg/ml. The examination using a reflecting fluorescent microscope revealed that the F-body found in human sperm was also present in the sperm of all the mammals but not in the cock after 24 h of staining. The enzyme-treated specimens showed higher incidences of F-bodies than specimens stained for 24 h without enzymatic digestion. These findings strongly suggest that the F-body is commonly present in the spermatozoa of many mammalian species.     

Clinical report: Recovery of a degenerating 14-day embryo in the uterine flush of a mare 7 days after ovulation

A 15-mm diameter degenerating embryonic vesicle and a normal, 200-u early blastocyst were recovered in a uterine flush of a mare 7 d after ovulation. From its size, the degenerating vesicle appeared to be 13 to 14 d of age. The mare had been bred during a previous cycle and then treated with prostaglandin 9 days after ovulation. The advanced vesicle that was recovered suggests that a conceptus from the previous cycle continued to grow for about 5 d after prostaglandin administration, and remained in the uterus during estrus, when plasma progesterone concentrations were below 1 ng/ml. From the estimated age of the conceptus, its development stopped at about the time the mare was inseminated. Had this conceptus survived through estrus and insemination, superfetation would have occurred.     

Use of an immediate, qualitative progesterone assay for determination of day of ovulation in an equine embryo transfer program

An immediate, qualitative enzyme-linked immunosorbent assay (ELISA) for progesterone was evaluated for use in determining the day of ovulation in an equine embryo transfer program. Plasma samples were collected from 27 mares from the third day of estrus to the second day of diestrus for 50 cycles. Ovulation was detected by ultrasound examination per rectum. Plasma progesterone concentrations were estimated using the qualitative assay to detect the time of the rise in progesterone after ovulation. Qualitative scores were compared to progesterone concentrations for the same samples as measured by a quantitative ELISA; the correlation between the two methods, expressed as a contingency coefficient, was 0.56. The accuracy of determining day of ovulation using qualitative progesterone results was compared to that achieved using the quantitative assay or detection of the first day of diestrus by teasing. Accuracy in determining day of ovulation +/- 1 d using the three methods was qualitative, 36/50 (72%); quantitative, 44/50 (88%); and teasing, 43/50 (86%). There was a significant difference in accuracy between the qualitative and quantitative progesterone assays (P<0.05).     

Production of d-Aminoacylase from Alcaligenes denitrificans subsp. xylosoxydans MI-4

A bacterial strain that produces d-aminoacylase was isolated from soil and identified as Alcaligenes denitrificans subsp. xylosoxydans MI-4. l-Aminoacylase activity in this strain was only 1 to 2% of d-aminoacylase activity. d-Aminoacylase was inducibly produced. N-Acetyl-dl-leucine was the best inducer, and the d-isomer had the ability to induce the enzyme. Enzymatic resolution of N-acetyl-dl-methionine with the crude enzyme was carried out, and the d/l ratio in the resolved methionine was approximately 100/7, suggesting that resolution with crude enzymes may become possible by removing small amounts of the contaminated l-form with l-amino acid oxidase.     

Production of normal piglets from microsurgically split morulae and blastocysts

The embryo splitting technique was applied to pig embryos, and the developmental ability of the split embryos was examined by means of in vitro culture and transfer. Morulae, early blastocysts and blastocysts were collected from Landrace x Large White F(1) gilts which had been mated to Duroc boars. The embryos were bisected with a fine glass or alloy (PtIr) needle after the softening of zonae pellucidae. The halved-embryos, which had either been placed in zonae pellucidae or not, were transferred to recipient gilts immediately after the micromanipulation (Experiment 1) or after cultivation for 15 to 20 h (Experiment 2). In Experiment 1, two fetuses were obtained from one of three recipients which had received 12 half-embryos. In Experiment 2, three of five recipients became pregnant, and in one recipient, seven piglets of a litter were obtained from 12 zona-free half-embryos produced from the original seven blastocysts. The results obtained indicate that a simple method not requiring the encasing of split embryos into zonae pellucidae is satisfactory to produce viable half-embryos.     

Arabinogalactan-Proteins from Primary and Mature Roots of Radish (Raphanus sativus L.)

Organ-specific variations in blood group H-like activity were observed in developing radish plants. A temporary increase in serological activity was found to occur in the roots at the earlier stages of development. Arabinogalactan-proteins (AGPs) were isolated from primary and mature roots, and investigated for changes in their physicochemical properties, structure, and serological activities. These root AGPs were composed mainly of l-arabinose and d-galactose but were distinguishable from each other in their contents of l-fucose as well as of protein and hydroxyproline. The structures of the carbohydrate moieties of the root AGPs were essentially similar to those of AGPs isolated from seeds and mature leaves in that they consisted of consecutive (1→3)-linked β-d-galactosyl backbone chains having side chains of (1→6)-linked β-d-galactosyl residues, to which α-l-arabinofuranosyl residues were attached in the outer regions. One prominent feature of the primary root AGPs was that they contained appreciable amounts of l-fucose, which was presumably responsible for expression of the serological activity. In their immunological reactions with rabbit anti-radish leaf AGP antibody, the root AGPs were shown to share common antigenic determinant(s) with those of seed and leaf AGPs.     

Ethylene production by sunflower cell suspensions : effects of plant growth retardants

From a variety of undifferentiated plant cell suspensions, 2,4-dichlorophenoxyacetic acid-dependent cells of sunflower (Helianthus annuus L. Spanners Allzweck) produced large quantities of ethylene. The maximum rate was about 1 nanomole × gram fresh weight⁻¹ × hour⁻¹ during the exponential growth phase. The action of various compounds known to interfere with ethylene formation in plant tissue was studied in sunflower cell suspensions. The influence on ethylene, 1-aminocyclopropanecarboxylic acid (ACC), and N-malonyl-ACC (MACC) levels suggested that the final steps in ethylene synthesis resemble those of other plant systems. This makes sunflower cells suitable for analyzing the effects of biologically active compounds on cellular ethylene biosynthesis. In particular, plant growth retardants of the norbornenodiazetine and triazole type inhibited ethylene production of sunflower cells. On the other hand, the ACC level was considerably elevated while that of MACC did not change significantly. It is assumed that the conversion of ACC to ethylene catalyzed by the ethylene-forming enzyme was influenced.     

Lipid Saturation Induced Microviscosity Increase Has No Effect on the Reducibility of Flash-Oxidized Cytochrome f in Pea Thylakoids

Homogeneous catalytic hydrogenation was used to modify the level of fatty acid unsaturation of thylakoid membranes in the pea chloroplast. Fluidity alteration has been monitored simultaneously using the spin-label probe, 16-doxyl stearate. Even in the case of 30% hydrogenation, no change in the reduction rate of flash-oxidized cytochrome f was observed, in contrast to the fact that the same decrease in the double-bond content of the thylakoid membrane resulted in a pronounced inhibition in the full-chain electron transport. We conclude that the rate of lateral diffusion of reduced plastoquinone is unaffected by the lowering of the fluidity of the thylakoid lipid matrix.     

Cell-specific expression of pyruvate, pi dikinase : in situ mRNA hybridization and immunolocalization labeling of protein in wheat seed

Pyruvate, Pi dikinase (PPDK) is a key enzyme in the C4 photosynthetic pathway. However, its metabolic role in C3 plants remains uncertain. Northern blot analyses of PPDK mRNAs from wheat leaves and seeds probed with maize PPDK cDNA indicates the presence of organ-specific mRNAs. Immunofluorescent labeling of protein in wheat seed demonstrate that the PPDK polypeptide and the ribulose-1, 5-bisphosphate carboxylase small subunit polypeptide are localized predominantly in the aleurone layer and the chlorophyllous pericarp tissue, respectively. This differential distribution of the two polypeptides in wheat seed is paralleled by the differential localization of the their mRNAs as revealed by in situ hybridization. These results suggest a distinct role of cytoplasmic PPDK in seeds, which is different from the well established role in C4 photosynthesis.