Papers by Sara Victoria Good
Frontiers in Plant Science
IntroductionThe phenomenal expansion of angiosperms has prompted many investigations into the fac... more IntroductionThe phenomenal expansion of angiosperms has prompted many investigations into the factors driving their diversification, but there remain significant gaps in our understanding of flowering plant species diversity.MethodsUsing the crown age of families from five studies, we used a maximum likelihood approach to classify families as having poor, predicted or high species richness (SR) using strict consensus criteria. Using these categories, we looked for associations between family SR and i) the presence of an inferred familial ancestral polyploidization event, ii) 23 life history and floral traits compiled from previously published datasets and papers, and iii) sexual system (dioecy) or genetically determined self-incompatibility (SI) mating system using an updated version of our own database and iv) geographic distribution using a new database describing the global distribution of plant species/families across realms and biomes and inferred range.ResultsWe find that more...
Evolution, Aug 1, 1997
The giant kangaroo rat, Dipodomys ingens (Heteromyidae), is an endangered rodent that inhabits ap... more The giant kangaroo rat, Dipodomys ingens (Heteromyidae), is an endangered rodent that inhabits approximately 3% of its estimated historic range. Its current distribution is centered in two geographic areas, situated about 150 km apart, in south-central California. We sequenced a 293 base-pair fragment at the 5' end of the control region in 95 giant kangaroo rats from nine localities to examine the genetic structure of extant populations. We determine that mutations in this section of the control region follow a negative binominal distribution, rather than a Poisson. However, the distance between haplotypes is small enough that the difference between a tree that corrects for the non-Poisson distribution of mutations and one that does not, is minimal. This implies that the use of methods that assume a Poisson distribution of mutations, such as those based on coalescent theory, are justified. We find that the correlation between levels of genetic diversity and estimated census size is poor. This suggests that population sizes have fluctuated over time or that populations have not been isolated from one another, or both. We also examine the hierarchical structure of populations and find that the southern populations are not genetically subdivided but that there is significant subdivision between northern and southern populations and between some northern subpopulations. The phylogeographic relationship between northern and southern populations can primarily be attributed to isolation by distance, although the time since divergence between them appears to be less than the age of either. To examine the phylogeographic relationships in more detail we construct a minimum spanning tree based on Tamura-Nei gamma-corrected distances and superimpose on it the geographic position of haplotypes. This reveals that there is more genetic distance between some northern haplotypes than between any northern and southern haplotypes, despite the geographic distance separating north from south and the larger size of the southern population. It also reveals that one northern population, in the Panoche Valley, contains old allelic lineages and shares ancestral polymorphism with several other populations. It also shows that two, small, geographically remote populations contain a surprising amount of genetic diversity, but that different population/geographic processes have affected the structure of that diversity. We estimate the average migration rate among all populations to be 7.5 per generation, and conclude that a disproportionate number of migration events involve gene flow with one northern population, the Panoche Valley. We find evidence for the hypothesis that there has been an increase in population size in the remaining populations in the north and suggest that the Panoche Valley could play a role in these expansions. Finally we discuss the probabilitiy that the genetic structure of the southern populations has been affected by fluctuations in size. These results are briefly compared to other studies on the genetic structure of rodent populations.
Tropical diseases, travel medicine and vaccines, Nov 29, 2019
Human immunodeficiency virus (HIV) remains a leading cause of global morbidity with the highest b... more Human immunodeficiency virus (HIV) remains a leading cause of global morbidity with the highest burden in Sub-Saharan Africa (SSA). For reasons that are incompletely understood, the likelihood of HIV transmission is several fold higher in SSA than in higher income countries, and most of these infections are acquired by young women. Residents of SSA are also exposed to a variety of endemic infections, such as malaria and various helminthiases that could influence mucosal and systemic immunology. Since these immune parameters are important determinants of HIV acquisition and progression, this review explores the possible effects of endemic infections on HIV susceptibility and summarizes current knowledge of the epidemiology and underlying immunological mechanisms by which endemic infections could impact HIV acquisition. A better understanding of the interaction between endemic infections and HIV may enhance HIV prevention programs in SSA.
Allergy, Asthma & Clinical Immunology, Dec 6, 2022
Background: To date, little consideration has been given to access to allergy-related care, despi... more Background: To date, little consideration has been given to access to allergy-related care, despite the fact that food allergy affects a considerable proportion of children. As such, the current study aimed to describe access to food allergy-related services in Canada and the United States (US). Methods: Participants were recruited via social media from March-July 2021 and were asked to complete an online survey focused on food allergy-related medical care. Participants were Canadian and US residents who live with a child < 18 years old, with ≥ 1 food allergy. A series of logistic regressions were used to assess the associations between country of residence and type of allergy testing utilized during diagnosis. Results: Fifty-nine participants were included in the analysis (Canadian: 32/59; 54.2%; US residents: 27/59; 45.8%). Relative to Canadian participants, US respondents were less likely to be diagnosed using an oral food challenge (OFC; OR 0.16; 95% CI 0.04; 0.75: p < 0.05). Compared to children diagnosed by age 2 years, those diagnosed at age 3 years and older were less likely to have been diagnosed using an OFC (OR 0.12; 95% CI 0.01; 1.01; p = 0.05). Conclusions: Access to food allergy-related services, varies between Canada and the US. We speculate that this variation may reflect differences in clinical practice and types of insurance coverage. Findings also underscore the need for more research centered on food allergy-related health care, specifically diagnostic testing, among larger and more diverse samples.
PLOS Pathogens, Jan 4, 2022
The penis is the primary site of HIV acquisition in heterosexual men. Elevated penile inflammator... more The penis is the primary site of HIV acquisition in heterosexual men. Elevated penile inflammatory cytokines increase sexual acquisition risk, and topically applied cytokines enhance foreskin HIV susceptibility in an explant model. However, the impact of penile-vaginal sex on these immune parameters is undefined. Heterosexual couples were recruited to the Sex, Couples and Science (SECS) Study, with the collection of penile swabs, semen, cervicovaginal secretions, and blood after a period of abstinence, and repeated sampling up to 72 hours after either condomless (n = 30) or condom-protected (n = 8) penile-vaginal sex. Soluble immune parameters were quantified by multiplex immunoassay. Co-primary immune endpoints were penile levels of IL-8 and MIG, cytokines previously linked to penile HIV acquisition. One hour after sex there were dramatic increases in penile IL-8 and MIG levels, regardless of condom use, with a gradual return to baseline by 72 hours; similar patterns were observed for other chemoattractant chemokines. Penile cytokine changes were similar in circumcised and uncircumcised men, and repeated measures ANOVA and ANCOVA models demonstrated that the degree of change after condomless sex was explained by cytokine levels in their partners' cervico-vaginal secretions. This may have important implications for the biology of penile HIV acquisition.
Communications Medicine
Background In women, most HIV infections are acquired through penile-vaginal sex. Inflammation in... more Background In women, most HIV infections are acquired through penile-vaginal sex. Inflammation in the female genital tract (FGT) increases the risk of HIV acquisition and transmission, likely through recruitment of HIV target cells and disruption of epithelial barrier integrity. Although sex may have important immune and epithelial effects, the impact of receptive penile-vaginal sex on the immune correlates of HIV susceptibility in the female genital tract is not well described. Methods STI-free heterosexual couples were recruited to the Sex, Couples and Science (SECS) Study, with the serial collection of cervical secretions (CVS), endocervical cytobrushes, blood and semen before and up to 72 h after either condomless (n = 29) or condom-protected (n = 8) penile-vaginal sex. Immune cells were characterized by flow cytometry, and immune factors including cytokines and soluble E-cadherin (sE-cad; a marker of epithelial disruption) were quantified by multiplex immunoassay. Co-primary en...
Frontiers in Immunology, 2020
ABSTRACTThe penis is the primary site of HIV acquisition in heterosexual men. Elevated penile inf... more ABSTRACTThe penis is the primary site of HIV acquisition in heterosexual men. Elevated penile inflammatory cytokines increase sexual acquisition risk, and topically applied cytokines enhance foreskin HIV susceptibility in an explant model. However, the impact of penile-vaginal sex on these immune parameters is undefined. Heterosexual couples were recruited to the Sex, Couples and Science (SECS) Study, with the collection of penile swabs, semen, cervico-vaginal secretions, and blood after a period of abstinence, and repeated sampling up to 72 hours after either condomless (n=30) or condom-protected (n=8) penile-vaginal sex. Soluble immune parameters were quantified by multiplex immunoassay. Co-primary immune endpoints were penile levels of IL-8 and MIG, cytokines previously linked to penile HIV acquisition. One hour after sex there were dramatic increases in penile IL-8 and MIG levels, regardless of condom use, with a gradual return to baseline by 72 hours; similar patterns were obse...
BMC Infectious Diseases, 2018
Background: Schistosoma mansoni infection has been associated with increased risk of HIV transmis... more Background: Schistosoma mansoni infection has been associated with increased risk of HIV transmission in African women. This association might be causal or mediated through shared socio-behavioural factors and associated coinfections. We tested the latter hypothesis in a cross-sectional pilot study in a cohort of women from a S. mansoni endemic region of Uganda. To validate the immunological effects of S. mansoni in this cohort, we additionally assessed known schistosomiasis biomarkers. Methods: HIV-uninfected non-pregnant adult women using public health services were tested for schistosomiasis using the urine circulating cathodic antigen test, followed by serology and Schistosoma spp.-specific PCR. Blood was obtained for herpes simplex virus (HSV)-2 serology, eosinophil counts and cytokine analysis. Samples collected from the genitourinary tract were used to test for classical sexually transmitted infections (STI), for bacterial vaginosis and to assess recent sexual activity via prostate-specific antigen testing. Questionnaires were used to capture a range of socioeconomic and behavioral characteristics. Results: Among 58 participants, 33 (57%) had schistosomiasis, which was associated with elevated levels of interleukin (IL)-10 (0.32 vs. 0.19 pg/ml; p = 0.038) and a trend toward increased tumour necrosis factor (TNF) (1.73 vs. 1.42 pg/ml; p = 0.081). Eosinophil counts correlated with levels of both cytokines (r = 0.53, p = 0.001 and r = 0.38, p = 0.019, for IL-10 and TNF, respectively); the association of eosinophilia with schistosomiasis was not significant (OR = 2.538, p = 0.282). Further, schistosomiasis was associated with lower age (per-year OR = 0.910, p = 0.047), being unmarried (OR = 0.263, p = 0.030), less frequent hormonal contraceptive (HC) use (OR = 0.121, p = 0.002, dominated by long acting injectable contraceptives) and a trend to longer time since penile-vaginal sex (OR = 0.350, p = 0.064). All women infected by Chlamydia trachomatis (n = 5), were also positive for schistosomiasis (Fisher's exact p = 0.064). Conclusions: Intestinal schistosomiasis in adult women was associated with systemic immune alterations, suggesting that associations with immunological correlates of HIV susceptibility warrant further investigation. S. mansoni associations with socio-behavioral parameters and C. trachomatis, which may alter both genital immunity and HIV exposure and/or acquisition risk, means that future studies should carefully control for potential confounders. These findings have implications for the design and interpretation of clinical studies on the effects of schistosomiasis on HIV acquisition.
Nature Communications, 2019
Schistosoma mansoni(Sm) infection has been linked with an increased risk of HIV acquisition in wo... more Schistosoma mansoni(Sm) infection has been linked with an increased risk of HIV acquisition in women. Therefore, defining the mechanism(s) by whichSmalters HIV susceptibility might lead to new HIV prevention strategies. Here, we analyze the impact of standardSmtherapy in HIV-uninfectedSm+ Ugandan adult women on genital HIV susceptibility and mucosal and systemic immunology. Schistosomiasis treatment induces a profound reduction of HIV entry into cervical and blood CD4+ T cells that is sustained for up to two months, despite transient systemic and mucosal immune activation and elevated genital IL-1α levels. Genital IFN-α2a levels are also elevated post-treatment, and IFN-α2a blocks HIV entry into primary CD4+ T cells ex vivo. Transcriptomic analysis of blood mononuclear cells post-Smtreatment shows IFN-I pathway up-regulation and partial reversal ofSm-dysregulated interferon signaling. These findings indicate thatSmtherapy may reduce HIV susceptibility for women withSminfection, pote...
bioRxiv, 2020
N-myristoylation refers to the attachment of a 14-carbon fatty acid onto the N-terminal glycine r... more N-myristoylation refers to the attachment of a 14-carbon fatty acid onto the N-terminal glycine residue of a target protein. The myristoylation reaction, catalyzed by N-myristoyltrasnferase (NMT), is essential for regulating cellular activities such as signal transduction, proliferation, migration, differentiation, and transformation. Although a considerable amount of research is performed on the overexpression of NMT in pathogenic conditions, a fundamental knowledge gap exists on the evolution of NMT and the functional impact of myristoylation for normal cellular development and functions. We performed evolutionary analyses of the NMT gene and found that most non-vertebrates harbor a single nmt gene and all vertebrates examined harbor two genes; nmt1 and nmt2. For the first time, we report that teleosts harbor two copies of nmt1, named nmt1a and nmt1b. We traced the evolutionary history of the chromosomal fragments hosting NMT1 and NMT2 in humans and found that NMT1 and NMT2 trace ...
Botany, 2008
In this paper, we seek to identify the genetic basis of self-incompatibility (SI) in Campanula ra... more In this paper, we seek to identify the genetic basis of self-incompatibility (SI) in Campanula rapunculoides L. through diallel analysis of full siblings; to characterize the growth of pollen tubes in vivo after incompatible and compatible pollination; and to determine whether the SI system is based on pistil S-RNases. Pollinations were performed among individuals from five diallel crosses and scored for both fruit set and pollen-tube growth to determine the genetic basis of SI. On a subset of these individuals with known cross-(in)compatibility relationships, additional crosses were performed and pistils collected 1, 3, 6, 12, and 24 h after pollination to assess both the percentage of pollen grains that had germinated on the stigma, and the number of pollen tubes that had grown 20%, 40% 60%, 80%, and 100% of the distance down the pistil over five time intervals. Finally, total pistillate proteins were extracted and subjected to isoelectric focusing and RNase activity staining to find evidence of a highly basic S-RNases associated with SI in the Solanaceae. We found evidence that the SI system was based on the haplotype of the male gametophyte, and was not sporophytic. Protein analyses showed that SI was not based on a pistillate S-RNase. The existence of modifiers of SI and possible polyploidy at the S-locus complicated the expression of SI in this species, and single-gene inheritance could not be determined. This represents the first published characterization of incompatibility in the family Campanulaceae.
New Phytologist, Oct 19, 2006
Summary The self‐incompatibility (SI) status of 571 taxa from the Asteraceae was identified and t... more Summary The self‐incompatibility (SI) status of 571 taxa from the Asteraceae was identified and the taxa were scored as having SI, partial SI or self‐compatibility (SC) as their breeding system. A molecular phylogeny of the internal transcribed spacer (ITS) region was constructed for 211 of these taxa. Macrophylogenetic methods were used to test hypotheses concerning the ancestral state of SI in the Asteraceae, the gain and loss of SI, the irreversibility of the loss of SI and the potential for partial SI or SC to be terminal states. The ancestral breeding system in the family could not be resolved. Both maximum likelihood and parsimony analyses indicated that transitions among all breeding system states provide the best fit to the data and that neither partial SI nor SC is a terminal state. Furthermore, the data indicated that the loss of SI is not irreversible, although breeding system evolution has been more dynamic in some clades than in others. These results are discussed within the context of evidence for the gain and loss of SI, the evolutionary role of partial SI and methodological assumptions of tests of breeding system evolution.
The American Naturalist, Apr 1, 2003
We employ a full reciprocal diallel design between 10 parental plants that differed in their stre... more We employ a full reciprocal diallel design between 10 parental plants that differed in their strength of self-incompatibility (SI; strong, intermediate, and weak) to examine parental effects on seed set and 10 components of fitness of progeny performance in Campanula rapunculoides. We perform ANOVAs to separate the influence of the strength of SI and the identity of the maternal and paternal parent on family performance. We calculate the phenotypic and genetic correlations between traits to determine potentially evolutionary constraints. Finally, we employ maximum likelihood methods to estimate the components of quantitative genetic variance, as defined by Cockerham and Weir in their BioModel c. Our most significant finding is that weak SI plants have high outcrossed seed set as maternal parents. We argue that direct or pleiotropic effects of modifiers of SI probably cause this. Second, we find that extranuclear interactions, as defined by the BioModel, have strong effects on seed set and several vegetative and flowering traits. These findings indicate that some maternal plants selectively provision seeds sired by specific paternal donors and that some of this variation appears to be associated with modifiers of the strength of SI. We find other sources of significant quantitative genetic variation for all of the traits we examine and discuss the possible role these play in the evolution of the reproductive system. Taken together, our findings show that variation in the strength of SI may influence levels of quantitative genetic variation that, in turn, can influence the reproductive success of individuals in C. rapunculoides
International Journal of Plant Sciences, Sep 1, 2001
The consequences of partial self-incompatibility on the breeding system of Campanula rapunculoide... more The consequences of partial self-incompatibility on the breeding system of Campanula rapunculoides is considered under conditions of natural pollination. We propagated two partially self-incompatible genotypes of C. rapunculoides and established them in pollinator exclusion cages along with 18 donor plants that differed from the focal plants (recipients) in their genotype at the glucose-1-phosphate isomerase (GPI) locus. Cages of plants were opened for pollinator access for 1 h/d, 24 h every fourth day, or left continuously open (control treatment), and the experiment was carried out in two consecutive years (1997 and 1998). After flowering, recipient plants were scored for percentage fruit set and mean seed number per fruit, and then seeds were screened for paternity (self or outcross). ANOVA analyses showed that the mean number of seeds per flower was significantly greater in 1998 than in 1997 and that it was affected by the amount of pollinator access. ANOVA analyses further show that selfing rates were higher in the treatment in which pollinator access was open 24 h every fourth day, while the open-1-h/d treatment did not differ from control cages in any aspect of the breeding system. Selfing rates were higher overall in 1998 than in 1997. We also find a weak effect of the genotype of the recipient and the position of the flower on the selfing rate, although the first result is not unexpected because the genotypes used in the experiment showed similar levels of self-fertility. Our data show that both between-and within-years selfing rates can respond to environmental variation in pollinator availability in C. rapunculoides.
Annals of Botany, Feb 14, 2009
† Background and Aims Selection may favour a partial or complete loss of self-incompatibility (SI... more † Background and Aims Selection may favour a partial or complete loss of self-incompatibility (SI) if it increases the reproductive output of individuals in the presence of low mate availability. The reproductive output of individuals varying in their strength of SI may also be affected by population density via its affect on the spatial structuring and number of S-alleles in populations. Modifiers increasing levels of self-compatibility can be selected when self-compatible individuals receive reproductive compensation by, for example, increasing seed set and/or when they become associated with high fitness genotypes. † Methods The effect of variation in the strength of SI and scrub density (low versus high) on seed set, seed germination and inbreeding depression in seed germination (d germ) was investigated in the partially self-incompatible species Flourensia cernua by analysing data from self-, cross-and open-pollinated florets. † Key Results Examination of 100 plants in both high and low scrub densities revealed that 51% of plants were strongly self-incompatible and 49 % varied from being self-incompatible to self-compatible. Seed set after hand cross-pollination was higher than after open-pollination for self-incompatible, partially self-incompatible and self-compatible plants but was uniformly low for strongly self-incompatible plants. Strongly self-incompatible and self-incompatible plants exhibited lower seed set, seed germination and multiplicative female fitness (floral display  seed set  seed germination) in open-pollinated florets compared with partially self-incompatible and self-compatible plants. Scrub density also had an effect on seed set and inbreeding depression: in low-density scrubs seed set was higher after open-pollination and d germ was lower. † Conclusions These data suggest that (a) plants suffered outcross pollen limitation, (b) female fitness in partially self-incompatible and self-compatible plants is enhanced by increased mate-compatibility and (c) plants in lowdensity scrubs received higher quality pollen via open-pollination than plants in high-density scrubs.
Springer eBooks, 2008
Within many self incompatible species there is variation among plants in self-fertility. Mutation... more Within many self incompatible species there is variation among plants in self-fertility. Mutations conferring partial or complete self-fertility occur in the Salleles themselves, in genes closely linked to the S-alleles or in unlinked genes that affect the downstream rejection pathway, in unlinked genes that modify the expression or turnover of the S-allele products, and in unlinked genes that modify the pistil environment. Populations with genetic polymorphisms for self-fertility can be used as natural laboratories to examine the dynamic interplay of the forces that shape the evolution of plant breeding systems. We find that all self-fertility mutations are beneficial in populations with few S-alleles and/or high rates of pollen limitation and they may result in stable polymorphisms when there are high levels of inbreeding depression and/or S-linked load as might occur in highly fragmented or low density populations and in those species prone to repeated bouts of colonisation and extinction. Abbreviations 120 K 120 kDa glycoprotein GSI Gametophytic SI HT-B/HT H-Top Band; a small, novel asparagine-rich protein mRNA messenger RNA PSF Pseudo-self-fertility
Plant Ecology, Mar 30, 2010
... patches are positively correlated with pollination rates (Ghazoul 2005; Kunin 1993; Steven et... more ... patches are positively correlated with pollination rates (Ghazoul 2005; Kunin 1993; Steven et al. ... The apparent contradiction of observing lower pollinator service, but higher reproductive output will be ... that pollinators respond more to small scale variation in plot density than to ...
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Papers by Sara Victoria Good