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1.
J Affect Disord ; 352: 281-287, 2024 May 01.
Article in English | MEDLINE | ID: mdl-38307131

ABSTRACT

BACKGROUND: Anhedonia, an impairment in the motivation for or experience of pleasure, is a well-established transdiagnostic harbinger and core symptom of mental illness. Given increasing recognition of early life origins of mental illness, we posit that anhedonia should, and could, be recognized earlier if appropriate tools were available. However, reliable diagnostic instruments prior to childhood do not currently exist. METHODS: We developed an assessment instrument for anhedonia/reward processing in infancy, the Infant Hedonic/Anhedonic Processing Index (HAPI-Infant). Exploratory factor and psychometric analyses were conducted using data from 6- and 12-month-old infants from two cohorts (N = 188, N = 212). Then, associations were assessed between infant anhedonia and adolescent self-report of depressive symptoms. RESULTS: The HAPI-Infant (47-items), exhibited excellent psychometric properties. Higher anhedonia scores at 6 (r = 0.23, p < .01) and 12 months (r = 0.19, p < .05) predicted elevated adolescent depressive symptoms, and these associations were stronger than for established infant risk indicators such as negative affectivity. Subsequent analyses supported the validity of short (27-item) and very short (12-item) versions of this measure. LIMITATIONS: The primary limitations of this study are that the HAPI-Infant awaits additional tests of generalizability and of its ability to predict clinical diagnosis of depression. CONCLUSIONS: The HAPI-Infant is a novel, psychometrically strong diagnostic tool suitable for recognizing anhedonia during the first year of life with strong predictive value for later depressive symptoms. In view of the emerging recognition of increasing prevalence of affective disorders in children and adolescents, the importance of the HAPI-Infant in diagnosing anhedonia is encouraging. Early recognition of anhedonia could target high-risk individuals for intervention and perhaps prevention of mental health disorders.


Subject(s)
Anhedonia , Depressive Disorder, Major , Child , Humans , Adolescent , Infant , Depression/diagnosis , Depression/epidemiology , Depressive Disorder, Major/psychology , Psychometrics , Self Report
2.
J Affect Disord ; 347: 635-644, 2024 02 15.
Article in English | MEDLINE | ID: mdl-38070749

ABSTRACT

BACKGROUND: We examined whether women with prenatal mood and anxiety disorders would exhibit differential pro- and anti-inflammatory marker trajectories during the prenatal and postpartum periods compared to women without these disorders. METHODS: Approximately 179 pregnant women participated in a longitudinal study conducted in two urban areas. Blood samples for inflammatory markers were collected at six study visits. The Structured Clinical Interview for the DSM-IV (SCID) was administered to participants scoring above cutoffs on anxiety and depression. Pregnant women with SCID Axis I diagnoses of mood and/or anxiety disorders were compared to other participants on inflammatory markers. Multilevel modeling tested associations between SCID diagnoses and within-person interleukin (IL)6 and IL10 trajectories. RESULTS: Prenatal SCID diagnoses were associated with linear, quadratic and cubic change in IL6 from prenatal to postpartum timepoints. Women with a prenatal SCID diagnosis had steeper decreases and increases in IL6 during prenatal and postpartum periods. SCID diagnoses were associated with lower IL10 in mid-pregnancy to postpartum (b = -0.078, SE = 0.019; p = .015). LIMITATIONS: Future studies would benefit from a larger sample size and a larger number of participants with SCID diagnoses. Future research should also examine whether different prenatal Axis 1 diagnoses are associated with different patterns of immune response in pregnancy. CONCLUSIONS: Pregnant women with prenatal mood and anxiety disorders had greater fluctuations in IL6 across prenatal and postpartum periods and lower IL10 through pregnancy and postpartum. They may have different proinflammatory states that remain after birth without a reciprocal anti-inflammatory response.


Subject(s)
Depression, Postpartum , Pregnancy Complications , Female , Pregnancy , Humans , Anxiety Disorders/diagnosis , Cytokines , Longitudinal Studies , Interleukin-6 , Interleukin-10 , Anxiety , Postpartum Period , Anti-Inflammatory Agents , Depression, Postpartum/diagnosis , Mood Disorders , Depression
3.
Child Psychiatry Hum Dev ; 54(2): 470-480, 2023 04.
Article in English | MEDLINE | ID: mdl-34626290

ABSTRACT

Capitalizing on a longitudinal cohort followed from gestation through adolescence (201 mother-child dyads), we investigate the contributions of severity and stability of both maternal depressive and perceived stress symptoms to adolescent psychopathology. Maternal depressive and perceived stress trajectories from pregnancy through adolescence were identified with latent class growth analyses, and associations with adolescent internalizing and externalizing symptoms were examined. For both depression and stress, the most common trajectory group comprised mothers displaying stable and low symptom levels over time, and adolescents of these mothers had the fewest internalizing and externalizing symptoms. Maternal membership to one or more aberrant trajectory groups predicted higher levels of internalizing and externalizing symptoms, determined by both maternal and adolescent self-report. This study indicates that profiles of multiple indicators of maternal psychopathology assessed across childhood, beginning prenatally, can provide critical additional insight into child psychopathology risk.


Subject(s)
Depression , Mental Disorders , Child , Female , Pregnancy , Humans , Adolescent , Depression/diagnosis , Mothers , Self Report , Stress, Psychological/complications , Mental Disorders/diagnosis , Longitudinal Studies , Psychopathology
4.
Psychon Bull Rev ; 29(4): 1480-1491, 2022 Aug.
Article in English | MEDLINE | ID: mdl-35132581

ABSTRACT

Prior studies of A:B::C:D verbal analogies have identified several factors that affect performance, including the semantic similarity between source and target domains (semantic distance), the semantic association between the C-term and incorrect answers (distracter salience), and the type of relations between word pairs. However, it is unclear how these stimulus properties affect performance when utilized together. To test their interactive effects, we created a verbal analogy stimulus set that factorially crossed these factors and presented participants with an analogical stem (A:B::C:?) with two response choices: an analogically correct (D) and incorrect distracter (D') term. The semantic distance between source and target word pairs was manipulated creating near (BOWL:DISH::SPOON:SILVERWARE) and far (WRENCH:TOOL::SAD:MOOD) analogies. The salience of an incorrect distracter (D') was manipulated using the sematic distance with the C-term creating low (DRAWER) and high (FORK) salience distracters. Causal, compositional, and categorical relations were presented across these conditions. Accuracies were higher for semantically near than far analogies and when distracter salience was low than high. Categorical relations yielded better performance than the causal and compositional relations. Moreover, a three-way interaction demonstrated that the effects of semantic distance and distracter salience had a greater impact on performance for compositional and causal relations than for the categorical ones. We theorize that causal and compositional analogies, given their less semantically constrained responses, require more inhibitory control than more constraining relations (e.g., categorical).


Subject(s)
Semantics , Humans
6.
Health Place ; 72: 102667, 2021 11.
Article in English | MEDLINE | ID: mdl-34700064

ABSTRACT

School active travel contributes to young people's physical activity levels, yet the prevalence is low, and declines with age. Based on determinants from the social-ecological model we investigated changes in school travel behaviour over the transition from childhood to adolescence in participants from the baseline and four-year follow-up of the SPEEDY cohort. Descriptive analysis examined how travel behaviours changed and were related to physical activity. Multinomial logistic regression investigated determinants. Some 38% of participants changed travel mode; 66% from active to passive. Passively traveling participants at follow-up showed a decrease in physical activity. Several social-ecological domains were associated with change. Findings suggest multicomponent interventions are required to support active travel in youth.


Subject(s)
Exercise , Schools , Adolescent , Child , Humans , Transportation , Travel , Walking
7.
Psychoneuroendocrinology ; 125: 105106, 2021 03.
Article in English | MEDLINE | ID: mdl-33340919

ABSTRACT

One of the key proposed agents of fetal programming is exposure to maternal glucocorticoids. Experimental animal studies provide evidence that prenatal exposure to elevated maternal glucocorticoids has consequences for hypothalamic-pituitary-adrenal (HPA) axis functioning in the offspring. There are very few direct tests of maternal glucocorticoids, such as cortisol, during human pregnancy and associations with infant cortisol reactivity. The current study examined the link between maternal prenatal cortisol trajectories and infant cortisol reactivity to the pain of inoculation in a sample of 152 mother-infant (47.4% girls) pairs. The results from the current study provide insight into fetal programming of the infant HPA axis, demonstrating that elevated prenatal maternal cortisol is associated with a larger infant cortisol response to challenge at both 6 and 12 months of age.


Subject(s)
Hypothalamo-Hypophyseal System , Prenatal Exposure Delayed Effects , Female , Glucocorticoids , Humans , Hydrocortisone , Infant , Male , Pituitary-Adrenal System , Pregnancy , Stress, Psychological
8.
Infant Behav Dev ; 60: 101468, 2020 08.
Article in English | MEDLINE | ID: mdl-32745812

ABSTRACT

A longitudinal study of a sample of women and their offspring from two urban areas (N = 233) was conducted to test whether maternal prenatal anxiety trajectories from early to late pregnancy are associated with 12-month infant developmental outcomes, independent of maternal postpartum anxiety symptoms, prenatal and postpartum depressive symptoms, parity, birth outcomes and maternal education. Three types of maternal anxiety trajectories over the course of pregnancy were identified and labeled increasing, decreasing, and stable-low. Only increasing maternal prenatal anxiety was associated with 12-month infant outcomes, specifically lower Bayley-III scores on receptive language and gross motor skills. Maternal anxiety measured at each individual timepoint in pregnancy was not associated with infant Bayley-III outcomes, highlighting the importance of examining trajectories of maternal affect.


Subject(s)
Anxiety/psychology , Child Development/physiology , Maternal Behavior/psychology , Pregnancy Complications/psychology , Prenatal Care/psychology , Prenatal Care/trends , Adult , Anxiety/diagnosis , Female , Humans , Infant , Longitudinal Studies , Male , Maternal Behavior/physiology , Pregnancy , Pregnancy Complications/diagnosis
9.
J Vis Commun Med ; 43(3): 103-118, 2020 Jul.
Article in English | MEDLINE | ID: mdl-32684050

ABSTRACT

Conversations surrounding end of life and death can be difficult or taboo for some, meaning that matters of organ and body donation are not widely discussed. To Donate or Not to Donate? That is the Question! is a comic developed to raise awareness and challenge common misconceptions about donation by encouraging the publics to engage in informed discussions about the different options available. This case study proposes graphic medicine as an alternative method of presenting donation information to a public audience, and illustrates how the comic medium can communicate body donation information in an accessible and engaging way.


Subject(s)
Graphic Novels as Topic , Health Education/methods , Tissue Donors/psychology , Tissue and Organ Procurement , Adult , Female , Humans , Male , United Kingdom
10.
Hum Microb J ; 182020 Dec.
Article in English | MEDLINE | ID: mdl-34485763

ABSTRACT

BACKGROUND: The oral microbiome is a complex assembly of microbial species, whose constituents can tilt the balance towards progression of oral disease or sustained health. Recently we identified sex-specific differences in the salivary microbiome contained within caries-active and caries-free children. In this study, we sought to ascertain if adjunctive dental therapies, including povidone iodine and chlorhexidine, were effective in shifting the cariogenic microbiome from dysbiosis to non-cariogenic health. DESIGN: We recruited young children (ages 2-12 years) to enter five enrollment groups, with each group (N = 9-30 participants/group) receiving caries restorative and/or adjunctive therapies, either singularly or in combination (OHSU IRB #6535). Saliva specimens were collected pre- and post-treatment (4-8 weeks) of caries preventive measures, and oral microbiota were identified using next generation sequencing (HOMINGS, Forsyth Institute, Cambridge, MA). RESULTS: With the use of multi-dimensional scaling plots, support vector machine learning, odds ratio analysis, and other statistical methods, we have determined that treatment with povidone iodine can shift the composition of the salivary cariogenic microbiome to include higher proportions of aerobic microorganisms, such as Stentrophomonas maltophila, as well as non-cariogenic, anaerobic microorganisms including Poryphyromonas and Fusobacterium species. CONCLUSION: We have identified microorganisms that are associated with caries-active children and have determined that povidone iodine is an effective adjunctive therapy that has the potential to shift the composition of the cariogenic microbiome to one more closely aligned with non-cariogenic health.

11.
Dev Psychobiol ; 62(1): 62-76, 2020 01.
Article in English | MEDLINE | ID: mdl-31172517

ABSTRACT

Maternal psychosocial stress during pregnancy can adversely influence child development, but few studies have investigated psychosocial stress during the postpartum period and its association with risk of toddler developmental delays. Moreover, given the expanding diversity of the U.S. population, and well-documented health and stress disparities for racial and ethnic minorities, research examining the effect of postpartum stress on risk of developmental delays in diverse populations is of critical importance. In this study, data from the Community Child Health Network provided the opportunity to test maternal postpartum stress as a predictor of toddler risk of developmental delay in a sample of African American, Latina and non-Hispanic White women and their toddlers (N = 1537) recruited in urban, suburban, and rural communities. Postpartum maternal stress over 1 year was operationalized as perceived stress, life events, and negative impact of life events. Regression results revealed higher risk of developmental delays in toddlers whose mothers experienced more negative life events, greater negative impact of events, and higher perceived stress over the year. Prenatal stress, pregnancy/birth complications, and postpartum depression did not explain these associations. Maternal postpartum stress may contribute to increased risk for developmental delays and is an important target for psychosocial intervention.


Subject(s)
Black or African American/ethnology , Developmental Disabilities/ethnology , Hispanic or Latino/statistics & numerical data , Puerperal Disorders/ethnology , Stress, Psychological/ethnology , White People/ethnology , Adolescent , Adult , Child, Preschool , Female , Humans , Infant , Longitudinal Studies , Male , United States/ethnology , Young Adult
12.
J Neuroimmunol ; 335: 577023, 2019 10 15.
Article in English | MEDLINE | ID: mdl-31445378

ABSTRACT

Immune dysregulation during pregnancy may influence behavior and neurodevelopment in offspring, but few human studies have tested this hypothesis. Using structural equation modeling, we examined associations between maternal inflammatory markers at 28 weeks gestation and child neurodevelopmental outcomes at 20 months of age in a sample of 1453 mother-child pairs. We observed several associations between maternal inflammatory markers measured in the late second or early third trimester and child neurodevelopmental outcomes. The direction of association for some markers was unexpected. Further research is warranted to confirm and elucidate the exact nature of these findings.


Subject(s)
Child Development , Inflammation , Prenatal Exposure Delayed Effects/immunology , Biomarkers/analysis , Cohort Studies , Female , Humans , Infant , Pregnancy , Seychelles
13.
Mol Neurobiol ; 56(7): 5000-5008, 2019 Jul.
Article in English | MEDLINE | ID: mdl-30430410

ABSTRACT

Findings from observational and experimental studies suggest that maternal inflammation during pregnancy is associated with autism spectrum disorder (ASD). We report the first study in humans to examine this association in a large prospective birth cohort. We studied 788 mother-child pairs from the Seychelles Child Development Study Nutrition Cohort 2. Thirteen inflammatory markers were measured in mothers' serum at 28 weeks' gestation, along with the sum of T-helper 1 (Th1) and 2 (Th2) cytokines. The Social Communication Questionnaire (SCQ) and Social Responsiveness Scale (SRS) were administered at age 7 years to obtain information on ASD phenotype. We evaluated associations between maternal inflammatory markers and ASD phenotype using multivariable linear regression. For the SCQ, increased MCP-1 (a chemokine that is upregulated in response to pro-inflammatory cytokines) was associated with fewer ASD symptoms (B = - 0.40; 95% CI = - 0.72, - 0.09). Increased IL-4 (a cytokine that is typically associated with an enhanced anti-inflammatory response) was associated with more ASD symptoms (B = 2.10; 95% CI = 0.78, 3.43). For the SRS, higher concentrations of the anti-inflammatory cytokine IL-10 were associated with fewer ASD symptoms (B = - 0.18; 95% CI = - 0.35, - 0.01), but only after removal of outliers. No associations were observed for other markers. These findings suggest that a shift in the maternal immune balance during pregnancy may be associated with ASD symptomatology. While the use of well-established measures that capture ASD phenotypic variability is a strength of the study, measurement of peripheral immune markers only once during gestation is a limitation. Our results should be confirmed using maternal immune markers measured throughout gestation.


Subject(s)
Autism Spectrum Disorder/blood , Autism Spectrum Disorder/immunology , Child Development/physiology , Inflammation Mediators/blood , Inflammation Mediators/immunology , Phenotype , Autism Spectrum Disorder/epidemiology , Biomarkers/blood , Child , Cohort Studies , Female , Humans , Male , Pregnancy , Prospective Studies , Seychelles/epidemiology , Surveys and Questionnaires
14.
Mol Ecol ; 27(23): 4839-4855, 2018 12.
Article in English | MEDLINE | ID: mdl-30187980

ABSTRACT

Detailed evaluations of genomic variation between sister species often reveal distinct chromosomal regions of high relative differentiation (i.e., "islands of differentiation" in FST ), but there is much debate regarding the causes of this pattern. We briefly review the prominent models of genomic islands of differentiation and compare patterns of genomic differentiation in three closely related pairs of New World warblers with the goal of evaluating support for the four models. Each pair (MacGillivray's/mourning warblers; Townsend's/black-throated green warblers; and Audubon's/myrtle warblers) consists of forms that were likely separated in western and eastern North American refugia during cycles of Pleistocene glaciations and have now come into contact in western Canada, where each forms a narrow hybrid zone. We show strong differences between pairs in their patterns of genomic heterogeneity in FST , suggesting differing selective forces and/or differing genomic responses to similar selective forces among the three pairs. Across most of the genome, levels of within-group nucleotide diversity (πWithin ) are almost as large as levels of between-group nucleotide distance (πBetween ) within each pair, suggesting recent common ancestry and/or gene flow. In two pairs, a pattern of the FST peaks having low πBetween suggests that selective sweeps spread between geographically differentiated groups, followed by local differentiation. This "sweep-before-differentiation" model is consistent with signatures of gene flow within the yellow-rumped warbler species complex. These findings add to our growing understanding of speciation as a complex process that can involve phases of adaptive introgression among partially differentiated populations.


Subject(s)
Gene Flow , Genetic Speciation , Genomic Islands , Songbirds/genetics , Animals , Canada , Genetic Variation , Genomics , Models, Genetic , Songbirds/classification
15.
Infant Ment Health J ; 38(1): 53-67, 2017 01.
Article in English | MEDLINE | ID: mdl-28042661

ABSTRACT

The goal of this study was to evaluate whether there are sex differences in children's vulnerability to caregiving risk, as indexed by trajectories of maternal depressive symptoms assessed from 2 to 18 months' postpartum, and children's rated attachment security in toddlerhood, adjusting for maternal social support and demographic risk. Analyses utilized longitudinal data collected for 182 African American mother-child dyads from economically diverse backgrounds. Participants were recruited at the time of the child's birth and followed to 18 months' postpartum. Results of conditional latent growth models indicated that an increasing rate of change in level of maternal depressive symptoms over time negatively predicted toddlers' felt attachment security. Higher social support was associated with decreasing levels of maternal depressive symptoms over time whereas higher demographic risk was associated with increasing levels of maternal depressive symptoms. A subsequent multigroup conditional latent growth model revealed that child sex moderated these associations. For male (but not female) children, a rapid increase in maternal depressive symptoms was associated with lower felt attachment security at 18 months. These findings suggest that boys, as compared to girls, may be more vulnerable to early caregiving risks such as maternal depression, with negative consequences for mother-child attachment security in toddlerhood.


Subject(s)
Depression, Postpartum , Mother-Child Relations/psychology , Mothers/psychology , Object Attachment , Risk , Sex Characteristics , Adolescent , Adult , Black or African American/psychology , Female , Humans , Infant , Longitudinal Studies , Male , Models, Theoretical , Prospective Studies , Psychiatric Status Rating Scales , Psychology, Child , Social Support , United States , Young Adult
16.
Mol Ecol ; 25(18): 4488-507, 2016 09.
Article in English | MEDLINE | ID: mdl-27484941

ABSTRACT

Recent technological developments allow investigation of the repeatability of evolution at the genomic level. Such investigation is particularly powerful when applied to a ring species, in which spatial variation represents changes during the evolution of two species from one. We examined genomic variation among three subspecies of the greenish warbler ring species, using genotypes at 13 013 950 nucleotide sites along a new greenish warbler consensus genome assembly. Genomic regions of low within-group variation are remarkably consistent between the three populations. These regions show high relative differentiation but low absolute differentiation between populations. Comparisons with outgroup species show the locations of these peaks of relative differentiation are not well explained by phylogenetically conserved variation in recombination rates or selection. These patterns are consistent with a model in which selection in an ancestral form has reduced variation at some parts of the genome, and those same regions experience recurrent selection that subsequently reduces variation within each subspecies. The degree of heterogeneity in nucleotide diversity is greater than explained by models of background selection, but is consistent with selective sweeps. Given the evidence that greenish warblers have had both population differentiation for a long period of time and periods of gene flow between those populations, we propose that some genomic regions underwent selective sweeps over a broad geographic area followed by within-population selection-induced reductions in variation. An important implication of this 'sweep-before-differentiation' model is that genomic regions of high relative differentiation may have moved among populations more recently than other genomic regions.


Subject(s)
Biological Evolution , Passeriformes/genetics , Selection, Genetic , Animals , China , Gene Flow , Genomics , Genotype , Siberia
17.
Arch Womens Ment Health ; 19(6): 1041-1050, 2016 12.
Article in English | MEDLINE | ID: mdl-27518635

ABSTRACT

The postpartum period brings a host of biopsychosocial, familial, and economic changes, which may be challenging for new mothers, especially those with trauma histories. Trauma-exposed women are at heightened risk for psychiatric symptomatology and reduced quality of life. The current study sought to evaluate whether a set of hypothesized promotive factors assessed during the first 18 months postpartum (positive parenting, family cohesion, and maternal resilience) are associated with life satisfaction in this population, after controlling for income and postpartum psychiatric symptoms. Analyses were based on data collected for 266 mother-infant dyads from a longitudinal cohort study, Maternal Anxiety during the Childbearing Years (MACY), of women oversampled for childhood maltreatment history. Hierarchical linear regression was used to evaluate the study hypotheses. Consistent with prior work, greater postpartum psychiatric symptoms and less income predicted poor perceptions of life quality. In hierarchical regressions controlling for income and psychiatric symptoms, positive parenting and family cohesion predicted unique variance in mothers' positive perceptions of life quality, and resilience was predictive beyond all other factors. Factors from multiple levels of analysis (maternal, dyadic, and familial) may serve as promotive factors predicting positive perceptions of life quality among women with childhood trauma histories, even those struggling with high levels of psychiatric or economic distress.


Subject(s)
Child Abuse , Child of Impaired Parents , Depression, Postpartum , Mothers/psychology , Psychological Trauma/complications , Quality of Life , Adult , Child Abuse/prevention & control , Child Abuse/psychology , Child Abuse/statistics & numerical data , Child of Impaired Parents/psychology , Child of Impaired Parents/statistics & numerical data , Depression, Postpartum/diagnosis , Depression, Postpartum/epidemiology , Depression, Postpartum/etiology , Depression, Postpartum/psychology , Family Health , Female , Humans , Infant , Mother-Child Relations/psychology , Parenting/psychology , Postpartum Period/psychology , Resilience, Psychological , United States
18.
Attach Hum Dev ; 16(5): 515-33, 2014.
Article in English | MEDLINE | ID: mdl-25028251

ABSTRACT

This study examined relationships among maternal reflective functioning, parenting, infant attachment, and demographic risk in a relatively large (N = 83) socioeconomically diverse sample of women with and without a history of childhood maltreatment and their infants. Most prior research on parental reflective functioning has utilized small homogenous samples. Reflective functioning was assessed with the Parent Development Interview, parenting was coded from videotaped mother-child interactions, and infant attachment was evaluated in Ainsworth's Strange Situation by independent teams of reliable coders masked to maternal history. Reflective functioning was associated with parenting sensitivity and secure attachment, and inversely associated with demographic risk and parenting negativity; however, it was not associated with maternal maltreatment history or PTSD. Parenting sensitivity mediated the relationship between reflective functioning and infant attachment, controlling for demographic risk. Findings are discussed in the context of prior research on reflective functioning and the importance of targeting reflective functioning in interventions.


Subject(s)
Child Abuse/psychology , Maternal Behavior/psychology , Mother-Child Relations/psychology , Mothers/psychology , Parenting/psychology , Adult , Female , Humans , Infant , Infant, Newborn , Middle Aged , Object Attachment , Socioeconomic Factors
19.
Mol Ecol ; 20(15): 3102-15, 2011 Aug.
Article in English | MEDLINE | ID: mdl-21689190

ABSTRACT

There is growing interest in understanding patterns of seasonal migratory connectivity between breeding and wintering sites, both because differences in migratory behaviour can be associated with population differentiation and because knowledge of migratory connectivity is essential for understanding the ecology, evolution and conservation of migratory species. We present the first broad survey of geographic variation in the nuclear genome of breeding and wintering Wilson's warblers (Wilsonia pusilla), which have previously served as a research system for the study of whether genetic markers and isotopes can reveal patterns of migratory connectivity. Using 153 samples surveyed at up to 257 variable amplified fragment length polymorphism markers, we show that Wilson's warblers consist of highly distinct western and eastern breeding groups, with all winter samples grouping with the western breeding group. Within the west, there is weak geographic differentiation, at a level insufficient for use in the assignment of wintering samples to specific areas. The distinctiveness of western and eastern genetic groups, with no known intermediates, strongly suggests that these two groups are cryptic species. Analysis of mitochondrial cytochrome b sequence variation shows that the estimated coalescence time between western and eastern clades is approximately 2.3 Ma, a surprisingly old time of divergence that is more typical of distinct species than of subspecies. Given their morphological similarity but strong genetic differences, western and eastern Wilson's warblers present a likely case of association between divergence in migratory behaviour and the process of speciation.


Subject(s)
Animal Migration , Genetic Variation , Genetics, Population , Songbirds/genetics , Amplified Fragment Length Polymorphism Analysis , Animals , Cell Nucleus/genetics , Genetic Markers , Genetic Speciation , Geography , North America , Principal Component Analysis , Sequence Analysis, DNA
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