Genetic, Structural, and Two-Dimensional Protein Electrophoretic Characterization of Normal and dek23 Mutant Embryogenesis in Maize (Zea mays L.)

Embryogenesis in maize (Zea mays L.) is a genetically regulated process that gives rise to a large embryo with shoot and root apical meristems, a large scutellum, and five or six leaf primordia. An embryo-lethal defective kernel mutation dek23, located on chromosome arm 2L, affects the formation of the shoot apical meristem, coleoptilar ring, and leaf primordia in mutant embryos. Comparison of mutant and normal embryo development at the structural and biochemical levels should give insight into the role of the dek23 normal gene product in normal development. Fresh dissection, light microscopy, and transmission electron microscopy of normal and mutant embryos at different developmental stages reveal a divergence between mutant and normal embryo morphology at nine days after pollination (dap). Mutant embryos are developmentally delayed and the cells of the shoot apical meristem region contain enlarged vacuoles and abnormal nuclei and subsequently become necrotic. Two-dimensional polyacrylamide gel protein profiles of normal embryos from the transition stage (nine dap) through stage 5/6 (40 dap) were obtained and used as standards for comparison to mutant embryo protein profiles at five different developmental stages. Normal embryo protein profiles exhibited a set of 16 landmark spots found at all stages. Two early embryonic proteins were found in embryos up to stage 1. Three stage specific proteins were observed at the coleoptilar stage, as well as a set of spots that increased in intensity until stage 3 and then decreased. Accumulation of globulin storage proteins was clearly evident. Mutant embryo profiles were generally similar to normal profiles of an earlier chronological age. Two landmark spots found in normal profiles were absent or diminished in mutant profiles. One early embryonic protein identified in normal profiles was also absent from mutant profiles, and may provide a marker for identifying mutant embryos before morphological differences are evident. Mutant embryos failed to accumulate any globulins. The dek23 locus was mapped 22 centimorgans distal to w3. Reduced sexual transmission of the mutant allele through the pollen and unequal distribution of mutant kernels on a self pollinated ear indicate that the dek23 gene is active in the male gametophyte

Minimally invasive biomarkers to detect maternal physiological status in sow saliva and milk

In this study, we aimed to validate existing plasma assays to measure biomarkers for maternal signalling in milk and saliva of lactating sows. These biological samples are minimally invasive to the animal and could give a physiological profile of maternal qualities available to their piglets. Sows were farrowed in a zero-confinement system, and their colostrum and milk samples were manually collected during naturally occurring let-downs (i.e. not induced) over the lactation period. Saliva sampling involved sows voluntarily accepting cotton buds to chew without restraint. Commercial kits designed for blood plasma were tested, and any modifications and results are given. We successfully measured total protein, cortisol, tumour necrosis factor-α (TNF-α) and oxytocin in pig milk and saliva and immunoglobulin G (IgG) in pig milk samples. We were unsuccessful at measuring relaxin and serotonin in these biological samples. We observed higher levels of biomarkers in milk than in saliva. The measurement of TNF-α in pig milk for the first time revealed increased levels with larger litters. This development will allow more detailed understanding of biomarkers in milk. There was also evidence that the minimally invasive technique of using saliva sampling did not interrupt natural oxytocin production around parturition

Facial expression as a potential measure of both intent and emotion

Abstract Facial expressions convey information on emotion, physical sensations, and intent. The much debated theories that facial expressions can be emotions or signals of intent have largely remained separated in animal studies. Here we integrate these approaches with the aim to 1) investigate whether pigs may use facial expressions as a signal of intent and; 2) quantify differences in facial metrics between different contexts of potentially negative emotional state. Facial metrics of 38 pigs were recorded prior to aggression, during aggression and during retreat from being attacked in a dyadic contest. Ear angle, snout ratio (length/height) and eye ratio from 572 images were measured. Prior to the occurrence of aggression, eventual initiators of the first bite had a smaller snout ratio and eventual winners showed a non-significant tendency to have their ears forward more than eventual losers. During aggression, pigs’ ears were more forward orientated and their snout ratio was smaller. During retreat, pigs’ ears were backwards and their eyes open less. The results suggest that facial expressions can communicate aggressive intent related to fight success, and that facial metrics can convey information about emotional responses to contexts involving aggression and fear