Novel analysis of global DNA methylation in the limbic system of the bovine brain

Citation: Cantrell, B. A., McKay, S. D., Weaber, R. L., Funston, R. N., & Lachance, H. (2016). Novel analysis of global DNA methylation in the limbic system of the bovine brain. Journal of Animal Science, 94, 43-43. doi:10.2134/jas2016.94supplement443xThere has been limited research focusing on the genetic-environmental interactions in bovine brains. Global DNA methylation has been measured in brains of several species, but has yet to be examined in bovine. The objective of this study was to characterize global DNA methylation in 9 regions of the limbic system in the bovine brain: amygdala, bed nucleus of the stria terminalis, cingulate gyrus, dorsal raphe, hippocampus, hypothalamus, nucleus accumbens, periaqueductal gray, and prefrontal cortex. DNA was extracted from brain and blood samples of 6 Red Angus × Simmental steers (less than 20 mo of age), using the DNA Extraction Kit from Agilent Technologies (Santa Clara, CA) and a phenol chloroform extraction. Percent of global DNA methylation was determined using the MethylFlash Methylated DNA Quantification Kit (Colormetric) from Epigentek (Farmingdale, NY). Varying amounts of global DNA methylation were observed among the 9 functionally distinct regions of the bovine limbic system. Amygdala, bed nucleus of the stria terminalis, cingulate gyrus, dorsal raphe, periaqueductal gray, prefrontal cortex, and nucleus accumbens are all significantly different (P < 0.05) from 1 or more brain tissue type, using a paired t test in SPSS (IBM, Armonk, NY). Conversely, global DNA methylation of blood was not significantly different (P < 0.05) from any brain tissue type. This study shows significant differences in global DNA methylation among different tissue types in the limbic system of the bovine brain. Understanding the differences in global DNA methylation within different tissues in the brain will facilitate future research involving the effects of differential methylation with regard to economically important traits

Efficacy of a Second Injection of Prostaglandin F2α in Yearling Beef Heifers Following Previous Estrus Synchronization

Angus- based, yearling beef heifers were utilized to determine the effects of administering a second prostaglandin F2α (PGF; Lutalyse, Zoetis Animal Health, Parsippany, NJ) injection to heifers who did not previously respond to estrus synchronization. All heifers were exposed to a melengestrolacetate (MGA)- PGF protocol. Following PGF injection, heifers were observed for estrus (estrus detection patches rubbed) for 3 d and inseminated. Heifers who did not show signs of estrus were placed with fertile bulls. Aft er 3 d with bulls, heifers with greater than 50% of the rub- off coating removed from estrus detection aids were considered to have been bred. One- half of the heifers not showing estrus received a second PGF injection; the other half were the controls and received no further treatment. Heifers remained with bulls for 4 d. Percentage expressing estrus was greater for heifers receiving a second PGF injection. However, pregnancy rate was similar between treatments

Evaluation of Commercial Genomic Tests for Maternal Traits in Crossbred Beef Cattle

DNA samples were collected from beef heifers born at the Gudmundsen Sandhills Laboratory and analyzed with a genomic test. Phenotypic data from these females were compiled and used in a regression analysis to evaluate the utility of these genomic scores as predictors for phenotypic outcomes. Th e genomic score for birth body weight (BW) was signifi cantly associated with animal birth BW. Th e genomic score for heifer pregnancy was not a statistically significant predictor of actual pregnancy. Neither dam age or the genomic score for stayability were significant predictors of actual reproductive longevity

Plasmonic nanoparticle monomers and dimers: From nano-antennas to chiral metamaterials

We review the basic physics behind light interaction with plasmonic nanoparticles. The theoretical foundations of light scattering on one metallic particle (a plasmonic monomer) and two interacting particles (a plasmonic dimer) are systematically investigated. Expressions for effective particle susceptibility (polarizability) are derived, and applications of these results to plasmonic nanoantennas are outlined. In the long-wavelength limit, the effective macroscopic parameters of an array of plasmonic dimers are calculated. These parameters are attributable to an effective medium corresponding to a dilute arrangement of nanoparticles, i.e., a metamaterial where plasmonic monomers or dimers have the function of "meta-atoms". It is shown that planar dimers consisting of rod-like particles generally possess elliptical dichroism and function as atoms for planar chiral metamaterials. The fabricational simplicity of the proposed rod-dimer geometry can be used in the design of more cost-effective chiral metamaterials in the optical domain.Comment: submitted to Appl. Phys.

Atomic-scale confinement of optical fields

In the presence of matter there is no fundamental limit preventing confinement of visible light even down to atomic scales. Achieving such confinement and the corresponding intensity enhancement inevitably requires simultaneous control over atomic-scale details of material structures and over the optical modes that such structures support. By means of self-assembly we have obtained side-by-side aligned gold nanorod dimers with robust atomically-defined gaps reaching below 0.5 nm. The existence of atomically-confined light fields in these gaps is demonstrated by observing extreme Coulomb splitting of corresponding symmetric and anti-symmetric dimer eigenmodes of more than 800 meV in white-light scattering experiments. Our results open new perspectives for atomically-resolved spectroscopic imaging, deeply nonlinear optics, ultra-sensing, cavity optomechanics as well as for the realization of novel quantum-optical devices

Effect of GnRH Injection at - 72 h in MGA- PGEstrus Synchronization Protocol

Yearling beef heifers from 2 locations were synchronized with melengestrol acetate (MGA)- prostaglandin F2α (PGF) fi xed time AI (TAI) protocol. At PGF administration 72 h before AI, heifers were randomly assigned to receive either 0 or 5 μg gonadotropinreleasing hormone (GnRH). Th e administration of 5 μg GnRH at PGF did not increase estrus activity or improve TAI pregnancy rates at either location (Location 1, 56% (GnRH) vs. 57%; Location 2, 59% (GnRH) vs. 53%). Administering GnRH at PGF increased (74% vs. 63%) pregnancy rates for heifers inseminated during a follow- up heat detection period at one location. A low dose of GnRH administered 72 h prior to AI in a 14 d MGA- PGF synchronization protocol does not increase pregnancy rates or estrus expression in yearling, beef females bred with TAI when compared to the normal MGAPGF synchronization protocol

Effect of Increasing Energy 30 days Prior to Artificial Insemination in Beef Heifers

A 3-yr study utilized 300 Angus-based, spring-born heifers to evaluate postweaning heifer development systems on gain and reproductive performance. Three groups of heifers were developed over the winter development period either grazing winter range or fed a dry lot diet targeted to 1.5 lb/d of gain in order to achieve 65% of their mature body weight at breeding. Thirty days prior to artificial insemination, heifers grazing winter rand entered the dry lot and were fed this same diet, one group of dry lot heifers remained on this diet, and the other received increased energy in the form of wet corn gluten feed. Post development body weight and average daily gain were greater among dry lot developed heifers. There were no differences in artificial insemination or final pregnancy rate. Results indicate that producers may use a 30-day increase in energy prior to artificial insemination to decrease overall development inputs in range heifers without compromising reproductive efficiency when compared to dry lot heifers receiving greater inputs

Artificial Insemination of Beef Heifers with Multi-Sire Sexed Semen

This study observed pregnancy outcomes resulting from artificial insemination of beef heifers with multi-sire sexed semen. It was hypothesized, pregnancy rates resulting from multi-sire sexed semen would be increased compared to pregnancy rates from prior studies using single-sire sexed semen. Producers looking to maximize the proportion of calves of one sex may consider the technique. Ultrasound determined pregnancy rate of heifers given multi-sire sexed semen was 65%, which is 12% greater than the average pregnancy rate reported in previous studies using single-sire sexed semen. After accounting for date of birth however, the adjusted AI conception rate was calculated to range between 55 and 62% with a calving rate between 51 and 57%. In summary, multiple sires may outperform single sires\u27 pregnancy rate to artificial insemination with sexed semen

Extending Melengestrol Acetate Treatment from Fourteen to Eighteen Days in Beef Heifers

This study compared estrus synchronization, estrus response, and artificial insemination pregnancy rates of beef heifers fed melengestrol acetate the normal 14-day period or extended to an 18-day period using the melengestrol acetate -prostaglandin- heat detect and timed artificial insemination protocol. Therefore, the purpose of this study was to evaluate if extending melengestrol acetate feeding by 4 days increases the number of heifers ovulating, which would result in greater estrus response and pregnancy rate in the whole herd. Early estrus response following prostaglandin administration occurred in heifers who averaged an earlier estrus response after melegestrol acetate withdrawal but extending the melengestrol acetate feeding period did not increase herd estrus synchronization, estrus response, or pregnancy rate. When necessary, producers may consider extending melengestrol acetate feeding an alternative option without significant differences in pregnancy rate (i.e.: scheduling conflicts)