The majority of pregnancy loss in cattle occurs between Days 8 and 16 of gestation, coincident with the initiation of conceptus elongation and the onset of maternal recognition of pregnancy. Differences in conceptus length on the same day of gestation may be related to an inherent lack of developmental competency or may simply be a consequence of asynchrony with the maternal environment. The objective of this work was to characterize differential patterns of mRNA expression between short and long bovine conceptuses recovered on Day 15 of gestation. Embryos were produced from super-ovulated Holstein donor cows, and groups of Grade-1 and Grade-3 compact morulas were transferred into recipient heifers at Day 6.5 of their cycle. Conceptuses were recovered at Day 15 of gestation, and measured to assess overall length and area. Total RNA was extracted and analyzed on individual GeneChip Bovine Genome Arrays (Affymetrix, Santa Clara, CA). Gene expression was compared between conceptuses derived from the transfer of Grade-1 versus Grade-3 embryos; no differences were identified in the profiles of Day-15 conceptuses of these different embryo grades. When gene expression was compared between conceptuses classified as either short (mean length of 4.2 ± 0.1 mm [standard error]) or long (24.7 ± 1.9 mm) upon recovery at Day 15 of gestation, a total of 348 genes were differentially expressed. Of these, 221 genes were up-regulated and 127 were down-regulated in long compared to short conceptuses. In summary, differences in gene expression were identified between conceptuses recovered on Day 15 of gestation, based on their length. These data may be used to identify genes and cellular pathways involved in enhanced conceptus elongation that could serve as markers of successful pregnancy. Mol. Reprod. Dev. 83: 424-441, 2016. © 2016 Wiley Periodicals, Inc.

Behavioral genetic mapping studies in model organisms predominantly use crosses originating from a single pair of inbred lines to determine the location of alleles that confer genetic variation in the trait of interest, and they often make sweeping generalizations about the genetic architecture of the trait based on these results. A previous study fine mapped mate preference variation between one pair of Drosophila pseudoobscura lines and identified 2 strong-effect behavioral quantitative trait loci (QTLs). Here, we replicated the previous study's mapping design to examine the extent of variation at these behavioral QTLs across 6 pairs of lines, but we were unable to detect effects of either QTL region in the pairs of lines studied. We suggest that the low-discrimination alleles at these 2 QTLs may occur at low frequency within D. pseudoobscura, although other explanations for the inconsistency are possible. These results underscore the need to examine multiple strains across a species when describing the genetic variation underlying behavioral traits.

Glutathione reductases catalyze the reduction of oxidized glutathione (glutathione disulfide, GSSG) using NADPH as the substrate to produce reduced glutathione (GSH), which is an important antioxidant molecule that helps maintain the proper reducing environment of the cell. A recombinant form of glutathione reductase from Colwellia psychrerythraea, a marine psychrophilic bacterium, has been biochemically characterized to determine its molecular and enzymatic properties. C. psychrerythraea glutathione reductase was shown to be a homodimer with a molecular weight of 48.7 kDa using SDS-PAGE, MALDI-TOF mass spectrometry and gel filtration. The C. psychrerythraea glutathione reductase sequence shows significant homology to that of Escherichia coli glutathione reductase (66 % identity), and it possesses the FAD and NADPH binding motifs, as well as absorption spectrum features which are characteristic of flavoenzymes such as glutathione reductase. The psychrophilic C. psychrerythraea glutathione reductase exhibits higher k cat and k cat/K m at lower temperatures (4 °C) compared to mesophilic Baker's yeast glutathione reductase. However, C. psychrerythraea glutathione reductase was able to complement an E. coli glutathione reductase deletion strain in oxidative stress growth assays, demonstrating the functionality of C. psychrerythraea glutathione reductase over a broad temperature range, which suggests its potential utility as an antioxidant enzyme in heterologous systems.

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