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Understanding how gene flow affects population divergence and speciation remains challenging. Differentiating one evolutionary process from another can be difficult because multiple processes can produce similar patterns, and more than one process can occur simultaneously. Although simple population models produce predictable results, how these processes balance in taxa with patchy distributions and complicated natural histories is less certain. These types of populations might be highly connected through migration (gene flow), but can experience stronger effects of genetic drift and inbreeding, or localized selection. Although different signals can be difficult to separate, the application of high-throughput sequence data can provide the resolution necessary to distinguish many of these processes. We present whole-genome sequence data for an avian species group with an alpine and arctic tundra distribution to examine the role that different population genetic processes have played in their evolutionary history. Rosy-finches inhabit high elevation mountaintop sky islands and high-latitude island and continental tundra. They exhibit extensive plumage variation coupled with low levels of genetic variation. Additionally, the number of species within the complex is debated, making them excellent for studying the forces involved in the process of diversification, as well as an important species group in which to investigate species boundaries. Total genomic variation suggests a broadly continuous pattern of allele frequency changes across the mainland taxa of this group in North America. However, phylogenomic analyses recover multiple distinct, well supported, groups that coincide with previously described morphological variation and current species-level taxonomy. Tests of introgression using D-statistics and approximate Bayesian computation reveal significant levels of introgression between multiple North American taxa. These results provide insight into the balance between divergent and homogenizing population genetic processes and highlight remaining challenges in interpreting conflict between different types of analytical approaches with whole-genome sequence data. [ABBA-BABA; approximate Bayesian computation; gene flow; phylogenomics; speciation; whole-genome sequencing.]

The genetic architecture of a phenotype can have considerable effects on the evolution of a trait or species. Characterizing genetic architecture provides insight into the complexity of a given phenotype and, potentially, the role of the phenotype in evolutionary processes like speciation. We use genome sequences to investigate the genetic basis of phenotypic variation in redpoll finches (Acanthis spp.). We demonstrate that variation in redpoll phenotype is broadly controlled by a ~55-Mb chromosomal inversion. Within this inversion, we find multiple candidate genes related to melanogenesis, carotenoid coloration, and bill shape, suggesting the inversion acts as a supergene controlling multiple linked traits. A latitudinal gradient in ecotype distribution suggests supergene driven variation in color and bill morphology are likely under environmental selection, maintaining supergene haplotypes as a balanced polymorphism. Our results provide a mechanism for the maintenance of ecotype variation in redpolls despite a genome largely homogenized by gene flow., Trait genetic architecture influences how populations evolve and adapt. Genomic analysis finds that an inversion links genetic variation controlling redpoll finch color and bill shape, allowing the maintenance of latitudinal ecotypes despite a genome largely homogenized by gene flow.

Examining differences among recently diverged populations can provide insight into the traits and evolutionary mechanisms that drive or maintain divergence. The genus Sturnella includes 2 recently diverged species, Sturnella magna (Eastern Meadowlark) and S. neglecta (Western Meadowlark), the former of which has a complex of subspecies distributed across the Americas. Of the S. magna subspecies that occur in the United States, S. m. lilianae is the only one with a disjunct range, occurring in the southwestern United States and central Mexico. It also has markedly different song patterns than all other S. magna subspecies. In order to assess population differentiation, we performed whole-genome sequencing of 35 birds and analyzed song characteristics from 85 birds. Songs from each species and S. m. lilianae were diagnosable using linear discriminant function analysis and support divergence in song between all taxa. Phylogenetic analysis and admixture proportions support 3 distinct clades within North American meadowlarks, and tests of introgression failed to detect a significant signal. Overall, our results indicate that S. m. lilianae exhibits high levels of genetic and vocal differentiation from both S. magna and S. neglecta, with no evidence of introgression between any group, and forms a distinct evolutionary lineage. We thus recommend the elevation of S. m. lilianae to species status.

Darwin's finches are considered a classic example of an adaptive radiation, and have been the focus of numerous studies from ecological and evolutionary perspectives. Few studies, however, have attempted to investigate the biogeographic origins of Darwin's finches. In this paper, we reconstruct the ancestral biogeography of Coerebinae, the tanager subfamily that contains Darwin's finches and their 14 closest relatives. We use this reconstruction to examine the origin of Darwin's finches, and the diversification of this clade of tanagers. We test multiple biogeographic models using the R package BioGeoBEARS utilizing a recent multilocus phylogeny. We used these models to examine 2 different hypotheses regarding the biogeographic origin of Darwin's finches. The majority of ancestral ranges within this subfamily were estimated as Caribbean restricted. Biogeographic models run using 8 regions suggest Darwin's finches arose from a long-distance dispersal event from the Caribbean Islands as opposed to ...

Known colloquially as ‘Old Man’s Beard’, Usnea is a genus of lichenized Ascomycete fungi characterized by having a fruticose growth form and cartilaginous central axis. The complete mitochondrial genomes of Usnea halei, U. mutabilis, U. subfusca, U. subgracilis, and U. subscabrosa were sequenced using Illumina data and then assembled de novo. These mitogenomes ranged in size from 52,486 bp (U. subfusca) to 94,464 bp (U. subgracilis). All were characterized by having high levels of intronic and intergenic variation, such as ORFs that encode proteins with homology to two homing endonuclease types, LAGLIDADG and GIY-YIG. Genes annotated within these mitogenomes include 14 protein-coding genes, the large and small ribosomal subunits (LSU and SSU), and 23–26 tRNAs. Notably, the atp9 gene was absent from each genome. Genomic synteny was highly conserved across the five species. Five conserved mitochondrial genes (nad2, nad4, cox1, cox2, and cox3) were used to infer a best estimate maximum likelihood phylogeny among these five Usnea and other relatives, which yielded relationships consistent with prior published phylogenies.

Avian evolution has generated an impressive array of patterns and colors in the ~10,000 bird species that exist on Earth. Recently, a number of exciting studies have utilized whole-genome sequencing to reveal new details on the genetics of avian plumage color. These findings provide compelling evidence for genes that underlie plumage variation across a wide variety of bird species (e.g., juncos, warblers, seedeaters, and estrildid finches). While much is known about large, body-wide color changes, these species exhibit discrete color differences across small plumage patches. Many genetic differences appear to be located in regulatory regions of genes rather than in protein-coding regions, suggesting gene expression is playing a large role in the control of these color patches. Taken together, these studies have the potential to broadly facilitate further research of sexual selection and evolution in these charismatic taxa.

To study the effect of weaning age on average daily gain (ADG), dry matter intake (DMI) and ruminal fermentation, 10 rumen-cannulated male Holstein calves were randomly assigned to one of two treatments: (i) early weaned at 8 weeks of age (235 l milk); (ii) conventionally weaned at 12 weeks of age (347 l milk). Twice daily grass hay (9.0 MJ ME x kg(-1) DM) and a dry total mixed ration (TMR) (11.6 MJ ME x kg(-1) DM) containing 15% alfalfa hay and 85% concentrates were offered separately. Water was available ad libitum. Ruminal fluid was collected via cannulas at weeks 9, 11, 13 and 15, twice weekly just prior to as well as 1, 3, 5 and 7 h after morning feeding. Calves of both treatments achieved adequate ADG (947 vs. 959 g; p0.05). Just-weaned calves rapidly increased DMI (1.1-2.5 kg TMR and 2.4-3.6 kg TMR for early- and conventionally-weaned calves, respectively). From weeks 10-12 early-weaned calves consumed significantly more dry feed than conventionally-weaned calves (week 10: 2.5 vs. 1.6 kg/d; week 12: 3.4 vs. 2.4 kg/d). Early weaning stimulates DMI supporting ruminal fermentation intensity, indicated by lower ruminal pH. After weaning, only early-weaned calves achieved critical average ruminal pH (week 9: 5.7 vs. 6.0, p = 0.017; week 11: 5.9 vs. 6.2, p = 0.007). Experimental treatment did not affect the concentration of ruminal short-chain fatty acids (SCFA). For all calves, the effects of the concentrate-rich TMR were shown by a high SCFA level (daily average: 137-152 mmol x l(-1)) and an acetate to propionate to butyrate ratio between 51:36:9 and 54:33:10.

Pistacia vera L. is grown as an economically valuable crop in a number of semi-arid regions worldwide. However, the species remains quite underutilized when considering its wide native range and inherent genetic diversity. Central Asia represents a large and diverse region where a wealth of P. vera genetic resources exists. Much of this region, which is the center of diversity and/or the center of origin of many important crops, has been inaccessible to the western world for centuries. Since the break up of the Soviet Union, Central Asia has become increasingly open and opportunities for reciprocal germplasm exchange and scientific collaborations are growing. To bring increased attention to the valuable P. vera genetic resources endemic to this region, and to promote its better utilization, management, and preservation, a description and history of the species from a Central Asian perspective, along with recent and ongoing activities, are discussed here.

Because alcohol or other drug use following adolescent substance abuse treatment is common, understanding mediators of posttreatment outcome could help improve treatment interventions. The authors conducted path analyses based on data from 552 adolescents (aged 12-18; 82% male) with cannabis abuse or dependence who participated in outpatient treatment. The analysis used the Family Conflict and Cohesion subscales, from the Family Environment Scale, and several scales and indices from the Global Appraisal of Individual Needs. Family conflict, family cohesion, and social support indirectly predicted substance use and substance-related problems as mediated by recovery environment and social risk. This model replicated across 4 follow-up waves (3, 6, 9, and 12 months postintake). These results support the idea of targeting environmental factors during continuing care as a way to improve treatment outcomes for adolescents with cannabis disorders.

Aims To examine the comparability, reliability and predictive validity of two instruments used to assess alcohol use and dependence: the Global Appraisal of Individual Needs (GAIN) and the Form 90 Timeline Followback (TLFB) method. Design, setting and participants Adolescents (n = 101) admitted to a residential treatment program in the United States were interviewed at intake with the GAIN, and again within a week with a variation of TLFB, called Form 90. Alcohol and cannabis measures were compared and used to predict the number of past-month substance abuse and dependence symptoms. Measurement Self-report measures of days of alcohol and cannabis use in the 90 days prior to intake, peak number of drinks/joints used, peak blood alcohol content (BAC) and alcohol and cannabis abuse and dependence symptom counts. Findings Results revealed that the measures had: (a) excellent comparability (r = 0.7–0.8) across the two instruments; (b) deteriorating reliability after reported peak BAC levels exceeded 0.50 and peak joints exceeding 19; and (c) similar and strong relationships between use measures and the number of abuse/dependence symptoms across measures and instruments. Conclusions In a sample of 101 adolescents who were admitted to residential treatment for alcohol or drug dependence, the corresponding measures from the two instruments produced comparable results. If the cross-validation of these two measures generalizes to adolescents treated in out-patient settings and other adolescent treatment populations, the GAIN and Form 90 may provide useful core alcohol measures for meta-analyses.

Comparisons of well-developed practice-based interventions with research-based interventions are rare. This quasi-experimental study compares the outcomes of 274 adolescents (75% male; 63% weekly+ users; 54% dependent; 27% prior treatment; 73% with co-occurring problems) who received Chestnut Health System's best-practice Outpatient Treatment (CHS) or Cannabis Youth Treatment (CYT) research-based interventions. Ninety-five percent of participants completed follow-up interviews at three, six, nine, and 12 months after their intake GAIN interview. Initially, the CYT cohort scores indicated greater severity on several substance-related measures, while the CHS cohort scored higher on prior mental health treatment, victimization, and illegal activities measures. Adolescents in the CHS cohort were more likely to have longer lengths of stay and receive over three times as many hours of treatment. Mixed effects models revealed that CHS participants were significantly more likely to report a decrease in recovery environment risk, an increase in self-help attendance after treatment, and greater decreases in emotional problems, while CYT participants were significantly more likely to report decreases in their substance use. The results suggest that neither the best-practice nor the research-based interventions were clearly superior and call for a more rigorous randomized field experiment to better understand the differences in effectiveness between interventions.

A transformation system for triploid bermudagrass ( Cynodon dactylon x C. transvaalensis cv. TifEagle) was established with a biolistic bombardment delivery system. Embryogenic callus was induced from stolons and maintained on Murashige and Skoog's medium supplemented with 30 microM dicamba, 20 microM benzylaminopurine, and 100 mg/l myo-inositol. Using the hygromycin phosphotransferase ( hpt) gene as the selectable marker gene, we obtained 75 transgenic lines from 18 petri dishes bombarded. Integration of the hpt gene into genomic DNA and transcription of hpt was confirmed by Southern and Northern blot analyses, respectively. Through suspension culture screening, we obtained homogeneously transformed plants showing stable transcription of the hpt gene.

Interactions between infiltrating T cells and keratinocytes via the secretion of the TH1 cytokines interleukin (IL) 2 and interferon gamma (INF-gamma), the keratinocyte growth factor transforming growth factor alpha (TGF-alpha) and the cytokines IL-6 and IL-8 are thought to be the predominant mechanisms inducing skin lesions in psoriatic patients. Systemic treatment of psoriasis with fumaric acid derivatives (FAEs) has been reported to be effective in the treatment of psoriasis, but the mode of action is still unknown. To clarify this phenomenon, keratinocytes from psoriatic patients as well as from healthy volunteers were mono- and cocultured with HUT 78 T cells with/without the addition of FAEs; the cytokine concentrations were then measured in the culture supernatants. Furthermore, mRNA expression was determined in epidermal growth factor (EGF) -activated keratinocytes as well as in phytohaemagglutinin (PHA)-activated HUT 78 T cells. Only dimethylfumarate (DMF) diminished IL-6 and TGF-alpha secretion in the psoriatic cocultures. However, it did not have this effect on cocultures from control subjects or on monocultures. DMF suppresses EGF-induced TGF-alpha mRNA induction in psoriatic keratinocytes. DMF inhibited INF-gamma secretion in all cultures but stimulated the IL-10 secretion. This immunomodulation away from the TH1 cytokine IFN-gamma to the TH2 cytokine IL-10 was confirmed in HUT 78 T cells by Northern blot analysis. An increased number of eosinophils is a known side-effect in patients treated with this drug, suggesting a clinical relevance of this immunomodulation in vivo. This immunomodulation and the suppression of cytokines from the psoriatic cytokine network could be responsible for the beneficial effect of DMF in the treatment of a hyperproliferative and TH1 cytokine-mediated skin disease.

Evidence suggests an association between alcohol consumption and psoriasis. This relationship is still undefined, although long-term alcohol intake influences the immune system. Interactions between T cells and keratinocytes are important for the pathogenesis of psoriasis, by secretion of pro-inflammatory cytokines and growth factors in psoriatic skin. IL-2, IL-6, IL-8, IFN-gamma and TGF-alpha are hallmark cytokines in a psoriatic cytokine network. We investigated whether ethanol influences the secretion of these cytokines using a co-culture model with keratinocytes from psoriatic patients (n = 9) or from healthy controls (n = 9), with HUT 78 lymphocytes, and determined the cytokine levels with or without ethanol treatment in the culture supernatants. TGF-alpha and IFN-gamma levels were elevated in the ethanol-treated psoriatic co-cultures, to 150% and 175% respectively, but neither in co-cultures with keratinocytes derived from healthy control individuals nor in monocultures. Treatment with ethanol elevated slightly the IL-6 levels in the monocultures from psoriatic and control keratinocytes to 125% but not in HUT 78 monocultures. In the psoriatic co-cultures, IL-6 levels were elevated in the culture supernatants to almost 160%, but they were not influenced by ethanol in co-cultures with control keratinocytes. The cytokine levels of IL-8 or IL-2 were not significantly influenced in the psoriatic mono- and co-cultures or in HUT 78 cultures. If ethanol influences the cytokine secretion of psoriatic keratinocytes and HUT 78 lymphocytes in co-culture conditions, these data suggest that ethanol could also influence the psoriatic cytokine network in vivo, which may explain the explain the aggravation of this disease in alcohol-consuming psoriatic patients.

Although progesterone has been recognized as essential for the establishment and maintenance of pregnancy, this steroid hormone has been recently implicated to have a functional role in a number of other reproductive events. The physiological effects of progesterone are mediated by the progesterone receptor (PR), a member of the nuclear receptor superfamily of transcription factors. In most cases the PR is induced by estrogen, implying that many of the in vivo effects attributed to progesterone could also be the result of concomitantly administered estrogen. Therefore, to clearly define those physiological events that are specifically attributable to progesterone in vivo, we have generated a mouse model carrying a null mutation of the PR gene using embryonic stem cell/gene targeting techniques. Male and female embryos homozygous for the PR mutation developed normally to adulthood. However, the adult female PR mutant displayed significant defects in all reproductive tissues. These included an inability to ovulate, uterine hyperplasia and inflammation, severely limited mammary gland development, and an inability to exhibit sexual behavior. Collectively, these results provide direct support for progesterone's role as a pleiotropic coordinator of diverse reproductive events that together ensure species survival.

In the cynomolgus monkey, rabbit and rat the architecture of the pars plana vasculature was investigated using scanning electron micrographs of resin casts. The most complex vessel architecture was found in the cynomolgus monkey. Here, the pars plana venules have affluxes from the ciliary processes, ciliary muscle and iris. Numerous interconnections between these venules exist in the central portion of the pars plana. Arterial affluxes reach the pars plana not until the choriocapillaries. The variations of this architecture in the rat and rabbit are not only caused by the different size of the ciliary muscle and its vascularization. In the rat the most peripheral part of the uveal supply of the retina represents a transition form between pars plana venules and the choriocapillaries. In the rabbit, two vascular layers exist in the pars plana while in the cynomolgus monkey and rat the pars plana vessels spread out in one plane. The functional significance of the vessel architecture and the species differences are discussed.

Field studies on nitrogen dynamics after cultivation of grain legumes Field trials were conducted in order to study the nitrogen dynamics in soil after cultivation of grain legumes and to investigate the possibility of reduction of nitrate leaching due to catch crops or suitable following crops. Accordingly, in 1989/90 soil samples were taken on 12 farms at depths of 0–80 cm in 4 week intervals and analysed for NO3-N. Furthermore, Brassica napus and Sinapis alba were sown after grain legumes on two farms, and at the experimental station Roggenstein field trials were carried out with different catch crops (Sinapis alba, Raphanus sativus, Lolium multiflorum and Pisum sativum) after grain peas. Considerable amounts of nitrogen (100–150 kg N/ha) in the form of crop residues (straw and grains) were left on the fields cultivated with grain legumes. After harvesting, nitrate content in the soil layer 0–80 cm was on grain legume fields almost twice as high as on fields cultivated with winter wheat. During autumn, the soil nitrate contents increased remarkably. In the soil layer 0–80 cm the maximum values rose to 140 kg N/ha after peas, to 120 kg N/ha after faba beans and only to 65 kg N/ha after winter wheat. The more intensive N-mineralization after peas compared to faba beans is due to a lower C/N-ratio of crop residues and an earlier harvest time of 2-3 weeks of peas. In winter extremely high N-leaching was measured on fallow land after cultivation of grain legumes. Cultivation of catch crops makes it possible to retain up to 110 kg N/ha in plant material. Raphanus sativus and Sinapis alba are most suitable for this purpose due to their high N-uptake even when they are sown late. Ploughing up catch crops in autumn results in a fast mineralization of their immobilized nitrogen. This implies the risk of N-leaching into deeper soil layers during winter, depending on the amount of rainfall and water capacity of the soil. Particularly on soils with low water capacity, early N-mineralization needs to be prevented by cultivating catch crops which freeze off or survive in winter. Cultivation of Brassica napus (winter form) after grain legumes leads to an extensive uptake of soil nitrate before the beginning of the seepage period, and therefore almost excludes enhanced N-leaching.

The seasonal distributions and biology of four species of billbug on New Jersey turfs during 1986 and 1987 were examined; Sphenophorus parvulus Gyllenhal, a common pest of turfgrass, and three additional species, S. venatus s.l. (Say), S. minimus Hart, and S. inaequalis (Say), that had previously been overlooked as pests of cool-season turfgrasses in New Jersey. Linear pitfall trap collections of adults indicated: (1) a nearly equal overall abundance of the four species, (2) greater activity of S. inaequalis in the early spring and autumn, and (3) continued activity of S. venatus through the summer. The abundance of S. venatus adults throughout the summer, and continuous egg laying of all four species through August suggested a partial second generation. Larvae of all four species were found damaging cool-season turfgrasses during July. Laboratory-rearing work found little difference in the number of days for egg hatching and pupation, but a longer larval period for S. venatus . To facilitate identification and study by turfgrass specialists, an illustrated key to eight known billbug turf pests is provided and their geographic distributions in the United States are reviewed.

Studies were conducted on the host plants of four billbug species (Coleoptera:Curculionidae: Sphenophorus parvulus Gyllenhal, S. venatus Chitt., S. inaequalis Say, and S. minimus Hart) found on New Jersey turfgrasses. A collection of 4803 adults from pure stands of various turfgrasses revealed all four billbugs on Kentucky bluegrass (Poa pratensis L.), tall fescue (Festuca arundinacea Schreb.), and perennial ryegrass (Lolium perenne L.), and S. parvulus, S. venatus, and S. minimus on Chewings fescue (F. rubra L. ssp. commutata Gaud.). Since the presence of larvae, pupae, or teneral adults more accurately indicates the host status of a grass species, immature billbugs were collected from plugs of the various grass species and reared to adults for identification. All four species were reared from immature billbugs found in Kentucky bluegrass turf; immatures of S. venatus, S. inaequalis, and S. minimus were found in tall fescue; S. venatus and S. minimus in perennial ryegrass; and S. inaequalis in strong creeping red fescue (F. rubra L. ssp. rubra). A laboratory experiment was also conducted in which billbug adults were confined in petri dishes with either Kentucky bluegrass, perennial ryegrass, tall fescue, or bermudagrass (Cynodon dactylon Pers.). Only minor differences were found between the four grasses in billbug survival, number of eggs laid, and amount of feeding. In general, bermudagrass was the least favored host and the other grasses were equally adequate hosts. The results of this study indicate a need for updating host-plant lists of these four billbug species.

This longitudinal study examined the relationships among the working alliance, treatment satisfaction, and posttreatment use among adolescents in treatment for substance abuse. Adolescents (N = 600) from the Cannabis Youth Treatment study (M. L. Dennis et al., 2002) completed measures of working alliance and treatment satisfaction as well as substance use and substance-related problems at intake and 3, 6, 9, 12, and 30 months' postintake. When controlling for initial substance use and substance-related problems, working alliance, but not treatment satisfaction, predicted use at 3 and 6 months' postintake. Neither working alliance nor treatment satisfaction were predictive of longitudinal patterns of posttreatment use. Implications for the assessment of working alliance and treatment satisfaction are discussed.

Glutaric acidemia type 1 (GA-1) is an autosomal recessive disorder characterized by a deficiency of glutaryl-CoA dehydrogenase (GCDH) activity. GA-1 is often associated with an acute encephalopathy between 6 and 18 months of age that causes striatal damage resulting in a severe dystonic movement disorder. Ten autopsy cases have been previously described. Our goal is to understand the disorder better so that treatments can be designed. Therefore, we present the neuropathological features of six additional cases (8 months-40 years), all North American aboriginals with the identical homozygous mutation. This cohort displays similar pathological characteristics to those previously described. Four had macroencephaly. All had striatal atrophy with severe loss of medium-sized neurons. We present several novel findings. This natural time course study allows us to conclude that neuron loss occurs shortly after the encephalopathical crisis and does not progress. In addition, we demonstrate mild loss of large striatal neurons, spongiform changes restricted to brainstem white matter and a mild lymphocytic infiltrate in the early stages. Reverse transcriptase-PCR to detect the GCDH mRNA revealed normal and truncated transcripts similar to those in fibroblasts. All brain regions demonstrated markedly elevated concentrations of GA (3770-21 200 nmol/g protein) and 3-OH-GA (280-740 nmol/g protein), with no evidence of striatal specificity or age dependency. The role of organic acids as toxic agents and as osmolytes is discussed. The pathogenesis of selective neuronal loss cannot be explained on the basis of regional genetic and/or metabolic differences. A suitable animal model for GA-1 is needed.

Aims To identify adolescent relapse trajectory groups following discharge from out-patient substance abuse treatment. Design, setting and participants Adolescents aged 12–18, who were assigned randomly to one of five out-patient interventions (n = 563) in four United States communities and followed-up 3, 6, 9, 12 and 30 months post-intake. Outcome measures Self-report measures of days using any alcohol or other drugs (AOD), days of alcohol use, days of cannabis use, days of heavy use, days of crack/cocaine use, days of heroin/opiate use, days AOD use interfered with responsibilities and days in a controlled environment. Findings Adolescents can be grouped empirically into five relapse trajectories over 30 months following out-patient treatment: (a) low AOD use with limited days in a controlled environment; (b) low AOD use with high days in a controlled environment; (c) moderate/decreasing AOD use; (d) increasing AOD use; and (e) consistently high AOD use. Conclusions There was considerable heterogeneity in the relapse trajectories, varying by the initial response to treatment, the stability (versus increase/decrease) of the response and an interaction with time in a controlled environment. Cannabis and alcohol were the two main substances involved, although the two groups with the poorest trajectories had increasing levels of cocaine, opiate and other substance use at the 30-month follow-up. This study demonstrates the chronicity of substance use even among a subgroup of adolescents and the importance of studying more complex longitudinal patterns of recovery.

Progesterone plays a critical role in transforming the nonpregnant uterus into an enriched environment specifically suited for the developing embryo. Its role in inducing and maintaining the pregnant state is paramount in mammalian systems and to a large extent, determines the success of any given pregnancy in the steps following fertilization. For years, reproductive biologists have tried to elucidate the actual mechanisms and the signaling pathways involved in mediating progesterone’s activity. Yet little is currently known about the cascade of events which initiate and communicate the inductive effects of this uterine steroid. It has only been in the past few years that molecular targets of progesterone regulation have really been identified and characterized with respect to mediating pregnancy (1). Although this area of research is clearly burgeoning forward with the advances of gene knock out techniques and the identification of essential “pregnancy” genes, the small handful of genes known to be essential for pregnancy lends only suggestive information as to what signaling pathways are essential mediators of a successful pregnancy.

Publisher Summary This chapter discusses the synthesis of phosphatidylglycerophosphate phosphatase from Escherichia coli (E. coli). The synthesis of phosphatidylglycero[ 32 P]phosphate substrate requires phosphatidylglycerophosphate synthase from E. coli . Phosphatidylglycerophosphate phosphatase is determined by a modification of the method Phosphatidylglycero[ 32 P]phosphate is dried out of chloroform and suspended with vortexing to a final concentration of 0.2 mM in a 2-fold concentrated assay mixture consisting of 100 mM Tris-HCl (pH 7.4), 0.24% triton X-100, 2 mM dithiothreitol, and 2 mM ethylenediaminetetraacetic acid. The phosphatidylglycerophosphate phosphatase activity is responsible for reaction is associated with the membrane fraction of E. coli and appears to be a composite of the activities of at least three gene products; therefore, many properties of this activity are based on assays performed on this composite of enzymes. The activities catalyzing reactions are localized to the cell membrane fraction but have different distributions between the two membranes of the cell envelope.

To further define the genes and gene products responsible for the in vivo conversion of phosphatidylglycerophosphate to phosphatidylglycerol in Escherichia coli, we disrupted two genes (pgpA and pgpB) which had previously been shown to encode gene products which carried out this reaction in vitro (T. Icho and C. R. H. Raetz, J. Bacteriol. 153:722-730, 1983). Strains with either gene or both genes disrupted had the same properties as the original mutants isolated with mutations in these genes, i.e., reduced in vitro phospholipid phosphatase activities, normal growth properties, and an increase in the level of phosphatidylglycerophosphate (1.6% versus less than 0.1% in wild-type strains). These results demonstrate that these genes are not required for either normal cell growth or the biosynthesis of phosphatidylglycerol in vivo. In addition, the total phosphatidylglycerophosphate phosphatase activity in the doubly disrupted mutant was reduced by only 50%, which indicates that there is at least one other gene that encodes such an activity and thus accounts for the lack of a dramatic effect on the biosynthesis of anionic phospholipids in these mutant strains. The phosphatidic acid and lysophosphatidic acid phosphatase activities of the pgpB gene product were also significantly reduced in gene-interrupted mutants, but the detection of residual phosphatase activities in these mutants indicated that additional genes encoding such phosphatases exist. The lack of a significant phenotype resulting from disruption of the pgpA and pgpB genes indicates that these genes may be required only for nonessential cell function and leaves the biosynthesis of phosphatidylglycerophosphate as the only step in E. coli phospholipid biosynthesis for which a gene locus has not been identified.

The architecture of the vasculature of the human anterior eye segment was studied by scanning electron microscopy of vascular resin casts. Regarding the major vessels it was found that the perforating branches of the anterior ciliary arteries (ACA) form an anastomozing circle which lies in the posterior portion of the ciliary muscle (intramuscular circle). The ACAs supply the outer and posterior parts of the ciliary muscle, partly the iris, and the peripheral choroid by recurrent ACA branches. The major arterial circle of iris (MACI) which lies more anteriorly is formed mainly by the long posterior ciliary arteries and supplies the inner and anterior portion of the ciliary muscle, the iris and the ciliary processes. The ciliary process vasculature consists of three different vascular territories with discrete arterioles and venules. The first vascular territory which is located at the anterior end of the major processes, is drained posteriorly by venules which pass the ciliary body without greater connections to the venules of the major ciliary processes. The second and third territories comprise the vasculature of the major and minor ciliary processes drained posteriorly by venules which are located at the margin of the ciliary processes. In supravital experiments with human autopsy eyes, a characteristic segment of arterioles supplying the first and second territory was found to be constricted after immersion with epinephrine in a similar way as in cynomolgus monkeys in vivo. Although the general arrangement of the ciliary process vessels is similar to that of the cynomolgus monkey, there are characteristic differences in the size of the territories and in the pattern of the capillary networks. The division of the ciliary process vasculature into three vascular territories may reflect a functional differentiation in the process of aqueous humour production