Divergence estimates and early evolutionary history of Figitidae (Hymenoptera: Cynipoidea)

We examine the phylogenetic relationships of Figitidae and discuss host use within this group in light of our own and previously published divergence time data. Our results suggest Figitidae, as currently defined, is not monophyletic. Furthermore, Mikeiinae and Pycnostigminae are sister‐groups, nested adjacent to Thrasorinae, Plectocynipinae and Euceroptrinae. The recovery of Pycnostigminae as sister‐group to Mikeiinae suggests two major patterns of evolution: (i) early Figitidae lineages demonstrate a Gondawanan origin (Plectocynipinae: Neotropical; Mikeiinae and Thrasorinae: Australia; Pycnostigminae: Africa); and (ii) based on host records for Mikeiinae, Thrasorinae and Plectocynipinae, Pycnostigminae are predicted to be parasitic on gall‐inducing Hymenoptera. The phylogenetic position of Parnips (Parnipinae) was unstable, and various analyses were conducted to determine the impact of this uncertainty on both the recovery of other clades and inferred divergence times; when Parnips was excluded from the total evidence analysis, Cynipidae was found to be sister‐group to [Euceroptrinae + (Plectocynipinae (Thrasorinae + (Mikeiinae + Pycnostigminae)))], with low support. Divergence dating analyses using BEAST indicate the stem‐group node of Figitidae to be c. 126 Ma; the dipteran parasitoids (Eucoilinae and Figitinae), were estimated to have a median age of 80 and 88 Ma, respectively; the neuropteran parasitoids (Anacharitinae), were estimated to have a median age of 97 Ma; sternorrhynchan hyperparasitoids (Charipinae), were estimated to have a median age of 110 Ma; the Hymenoptera‐parasitic subfamilies (Euceroptinae, Plectocynipinae, Trasorinae, Mikeiinae, Pycnostigminae, and Parnipinae), ranged in median ages from 48 to 108 Ma. Rapid radiation of Eucoilinae subclades appears chronologically synchronized with the origin of their hosts, Schizophora (Diptera). Overall, the exclusion of Parnips from the BEAST analysis did not result in significant changes to divergence estimates. Finally, though sparsely represented in the analysis, our data suggest Cynipidae have a median age of 54 Ma, which is somewhat older than the age of Quercus spp (30–50 Ma), their most common host.     

Maternal prenatal depressive symptoms predict infant NR3C1 1F and BDNF IV DNA methylation

Prenatal maternal psychological distress increases risk for adverse infant outcomes. However, the biological mechanisms underlying this association remain unclear. Prenatal stress can impact fetal epigenetic regulation that could underlie changes in infant stress responses. It has been suggested that maternal glucocorticoids may mediate this epigenetic effect. We examined this hypothesis by determining the impact of maternal cortisol and depressive symptoms during pregnancy on infant NR3C1 and BDNF DNA methylation. Fifty-seven pregnant women were recruited during the second or third trimester. Participants self-reported depressive symptoms and salivary cortisol samples were collected diurnally and in response to a stressor. Buccal swabs for DNA extraction and DNA methylation analysis were collected from each infant at 2 months of age, and mothers were assessed for postnatal depressive symptoms. Prenatal depressive symptoms significantly predicted increased NR3C1 1F DNA methylation in male infants (β = 2.147, P = 0.044). Prenatal depressive symptoms also significantly predicted decreased BDNF IV DNA methylation in both male and female infants (β = −3.244, P = 0.013). No measure of maternal cortisol during pregnancy predicted infant NR3C1 1F or BDNF promoter IV DNA methylation. Our findings highlight the susceptibility of males to changes in NR3C1 DNA methylation and present novel evidence for altered BDNF IV DNA methylation in response to maternal depression during pregnancy. The lack of association between maternal cortisol and infant DNA methylation suggests that effects of maternal depression may not be mediated directly by glucocorticoids. Future studies should consider other potential mediating mechanisms in the link between maternal mood and infant outcomes.     

Effect of the hepatocarcinogen ethionine on hepatic messenger RNA synthesis.

An experiment was conducted to determine if any changes resulted in the proportion of hepatic messenger RNA following treatment with ethionine, a hepatocarcinogen. The relative specific activity of the total RNA isolated from nontumor-like tissues was increased in Sprague-Dawley rats fed ethionine. However, the percentage of total RNA that was message was found to be decreased in the ethionine-treated rats.     

Endogenous xenobiotic enzyme levels in mammalian cells.

The response of mammalian cell lines to chemicals depends, in part, on the exogenous activation system used for the induction of a biological response. This could be attributed to differences in the expression of enzymes involved in xenobiotic metabolism. We have measured the activities of benzo[a]pyrene hydroxylase, dimethylaminoazobenzene N-demethylase, catalase, superoxide dismutase, peroxidase and glutathione-S-transferase in human lymphoblast TK6, mouse lymphoma L5178Y, Chinese hamster ovary (CHO) and lung (V79) and mouse C3H10T1/2 cell lines as well as in primary hepatocytes and S9 preparations of liver from male F344 rats. Nitroreductase was also measured in some of these preparations. Human lymphoblast TK6 and mouse C3H10T1/2 cells had the capacity to metabolize dimethylaminoazobenzene and the latter cell line also metabolized benzo[a]pyrene, indicating the presence of constitutive mono-oxygenase activity. Cytochrome P450 could not be detected spectrophotometrically in the cell lines. Western blot analysis indicated that P450 from the P450IIA family is expressed in C3H10T1/2 cells. Reactivity was also observed with an antibody to P450IA2; however, the identity of this protein remains uncertain. Superoxide dismutase, catalase and peroxidase, which protect cells against oxygen radical damage, were found in all the cell lines and in rat hepatocytes and S9. The human lymphoblast TK6 cell line, however, had the least of each of these three enzymes. Glutathione-S-transferase activity was detected at varying levels in all cell types. Nitroreductase activity was high in S9 and Chinese hamster ovary cells and lower in mouse lymphoma and Chinese hamster V79 cells.     

A [Ca + Mg]-ATPase and active Ca transport in the plasma membranes isolated from ram sperm flagella

Plasma membranes isolated from the flagella of ram ejaculated sperm were found to contain a [Ca²⁺ + Mg²⁺]-ATPase. Freeze-fracture electron microscopy showed the membranes occur as vesicles. The membrane vesicles actively accumulate Ca²⁺, uptake was reversed by the ionophore A23187 and inhibited by either ruthenium red or La³⁺. The plasma membranes contain two major proteins, designated proteins A and B, with molecular weights of 109,000 and 18,300 daltons, respectively. Protein B is not detected in plasma membranes isolated from ram epididymal sperm. The plasma membrane Ca²⁺ pump may be modulated by protein factors present in seminal plasma.     

Acyl carrier protein structural classification and normal mode analysis

All acyl carrier protein primary and tertiary structures were gathered into the ThYme database. They are classified into 16 families by amino acid sequence similarity, with members of the different families having sequences with statistically highly significant differences. These classifications are supported by tertiary structure superposition analysis. Tertiary structures from a number of families are very similar, suggesting that these families may come from a single distant ancestor. Normal vibrational mode analysis was conducted on experimentally determined freestanding structures, showing greater fluctuations at chain termini and loops than in most helices. Their modes overlap more so within families than between different families. The tertiary structures of three acyl carrier protein families that lacked any known structures were predicted as well.     

In vivo rates of erythrocyte glutathione synthesis in adults with sickle cell disease

Despite reports of lower GSH concentration in sickle cell disease (SCD), the in vivo kinetic mechanism(s) responsible for GSH deficiency is unknown. To determine whether suppressed synthesis was responsible for the lower erythrocyte GSH concentration, we used a primed intermittent infusion of [(2)H(2)]glycine to measure erythrocyte GSH synthesis in vivo in 23 individuals with homozygous beta(s) SCD and 8 healthy controls. Erythrocyte cysteine concentration, the rate-limiting precursor for GSH synthesis, plasma markers of oxidant damage, and dietary intakes of energy and protein were also measured. Compared with values of controls, SCD subjects had significantly lower erythrocyte GSH (P < 0.04) and cysteine concentrations (P < 0.004) but significantly faster fractional rates of GSH synthesis (P < 0.02). The absolute rates of GSH synthesis in SCD subjects compared with control subjects was greater by approximately 57% (P = 0.062). However, the concentrations of markers of oxidative damage, plasma derivatives of reactive oxygen metabolites, plasma nitrotyrosine, urinary isoprostane-to-creatinine ratio, and GSH-to-GSSG ratio, as well as dietary intakes of energy, protein, and GSH precursor amino acids, were not different between SCD subjects and controls. The findings of this study suggest that the lower erythrocyte GSH of SCD patients is not due to suppressed synthesis or impaired regeneration but rather to increased consumption. In addition, the lower erythrocyte cysteine concentration plus the faster rate of GSH synthesis strongly suggest that the endogenous cysteine supply is not sufficient to meet all anabolic demands; hence, cysteine may be a conditionally essential amino acid in individuals with SCD.