Molecular Systematics and Biogeography of Dieteria (Asteraceae: Astereae)

The generic classification of the eucalypts, especially recognition of the genus Corymbia, has been controversial. The phylogeny of Corymbia and related eucalypt groups was investigated using nuclear ETS sequences, and combined ETS and ITS sequences. Both the ETS and combined datasets support the monophyly of Corymbia. Three major eucalypt clades are confirmed: Corymbia + Angophora; Eucalyptus s.s.; and the Eucalyptopsis group. Within Corymbia, relationships are broadly consistent with phylogenies based on morphological and anatomical characters; sections Ochraria, Blakearia, and Politaria are all supported as monophyletic; sect. Rufaria is monophyletic with the inclusion of the monotypic sect. Apteria. Within Eucalyptus s.s., relationships are generally consistent with those shown by previous molecular studies. Within the Eucalyptopsis group, Allosyncarpia is sister to the clade Stockwellia + Eucalyptopsis. Relationships between the major eucalypt clades are equivocal, but combined analysis of ETS and ITS data shows Corymbia + Angophora as sister to Eucalyptus—the rainforest taxa of the Eucalyptopsis group being outside this clade. Patterns of relationship and distribution are consistent with differentiation of major lineages of Corymbia prior to the isolation of taxa (now relictual) in eastern and south‐western Australia, arguably before the mid‐Miocene.

Spatial patterns in recruitment and growth of the mussel Mytilus californianus (Conrad) in southern and northern California, USA, two regions with differing oceanographic conditions

Mitochondrial DNA evolution in the Anaxyrus boreas species group

Ninety-three taxa comprising thirty-two genera (plus four outgroups from Lobeliaceae) were used to estimate a phylogeny of the Campanulaceae based on ITS sequences of nuclear ribosomal DNA. From 2629 most parsimonious trees, a strict consensus tree with bootstrap values was constructed, in addition to a phylogram showing branch lengths. The topologies of these two trees are discussed in relation to the pollen and capsule morphology within the family, in addition to chromosome number and geographical distribution. The results show that there is a major dichotomy between the colpate/colporate pollen alliance (platycodonoid taxa) and the porate pollen alliance (wahlenbergioid and campanuloid taxa). Both these major alliances are monophyletic. Within the porate alliance there are two major clades, the wahlenbergioids and the campanuloids. The campanuloid Glade is further subdivided into two major clades representing the Rapunculus and the Campanula s. str. groups of taxa, plus three smaller clades that are considered as transitional taxa. It is argued that the family originated in a fragmenting West Gondwanaland and that tectonic processes are responsible for the major dichotomy in the family. The colpate/colporate platycodonoids subsequently remained relatively relictual in Asia, whereas the porate taxa spread over much of the Northern and Southern Hemispheres. The campanuloid lineage spread over the Northern Hemisphere from a major evolutionary center in the Mediterranean region and is represented in North America only by the Rapunculus group. The wahlenbergioid lineage is widely dispersed across the southern continents and oceanic islands but has a major secondary center of diversification in southern Africa. The use of ITS provides insights for future investigations and a phylogenetic framework that can be tested with other data sets. Its limitations for phylogeny reconstruction are briefly discussed. More extensive taxon sampling and additional data sets are required to refine these results and for a new classification of the Campanulaceae to be proposed.

BackgroundTrypanosoma cruzi, causative agent of Chagas disease in humans and dogs, is a vector-borne zoonotic protozoan parasite that can cause fatal cardiac disease. While recognized as the most economically important parasitic infection in Latin America, the incidence of Chagas disease in the United States of America (US) may be underreported and even increasing. The extensive genetic diversity of T. cruzi in Latin America is well-documented and likely influences disease progression, severity and treatment efficacy; however, little is known regarding T. cruzi strains endemic to the US. It is therefore important to expand our knowledge on US T. cruzi strains, to improve upon the recognition of and response to locally acquired infections.Methodology/Principle FindingsWe conducted a study of T. cruzi molecular diversity in California, augmenting sparse genetic data from southern California and for the first time investigating genetic sequences from northern California. The vector Triatoma protracta was collected from southern (Escondido and Los Angeles) and northern (Vallecito) California regions. Samples were initially screened via sensitive nuclear repetitive DNA and kinetoplast minicircle DNA PCR assays, yielding an overall prevalence of approximately 28% and 55% for southern and northern California regions, respectively. Positive samples were further processed to identify discrete typing units (DTUs), revealing both TcI and TcIV lineages in southern California, but only TcI in northern California. Phylogenetic analyses (targeting COII-ND1, TR and RB19 genes) were performed on a subset of positive samples to compare Californian T. cruzi samples to strains from other US regions and Latin America. Results indicated that within the TcI DTU, California sequences were similar to those from the southeastern US, as well as to several isolates from Latin America responsible for causing Chagas disease in humans.Conclusions/SignificanceTriatoma protracta populations in California are frequently infected with T. cruzi. Our data extend the northern limits of the range of TcI and identify a novel genetic exchange event between TcI and TcIV. High similarity between sequences from California and specific Latin American strains indicates US strains may be equally capable of causing human disease. Additional genetic characterization of Californian and other US T. cruzi strains is recommended.

PurposeThis study aims to investigate practice changes among Southern and Northern California's radiation oncology centers during the COVID‐19 pandemic.MethodsOn the online survey platform SurveyMonkey, we designed 10 survey questions to measure changes in various aspects of medical physics practice. The questions covered patient load and travel rules; scopes to work from home; new protocols to reduce corona virus disease‐2019 (COVID‐19) infection risk; availability of telemedicine; and changes in fractionation schedules and/or type of treatment plans. We emailed the survey to radiation oncology centers throughout Northern and Southern California, requesting one completed survey per center. All responses were anonymized, and data were analyzed using both qualitative and quantitative research methods.ResultsAt the end of a 4‐month collection period (July 2, 2021 to October 11, 2021), we received a total of 61 responses throughout Southern and Northern California. On average, 4111 patients were treated per day across the 61 centers. New COVID‐19‐related department and hospital policies, along with hybrid workflow changes, infectious control policies, and changes in patient load have been reported. Results also showed changes in treatment methods during the pandemic, such as increased use of telemedicine, hypofractionation for palliative, breast cancer, and prostate cancer cases; and simultaneous boosts, compared to sequential boosts.ConclusionOur California radiation oncology center population study shows changes in various aspects of radiation oncology practices during the COVID‐19 pandemic. This study serves as a pilot study to identify possible correlations and new strategies that allow radiation oncology centers to continue providing quality patient care while ensuring the safety of both staff and patients.

Abstract. Carbonaceous aerosols impact climate directly by scattering and absorbing radiation, and hence play a major, although highly uncertain, role in global radiative forcing. Commonly, ambient carbonaceous aerosols are internally mixed with secondary species such as nitrate, sulfate, and ammonium, which influences their optical properties, hygroscopicity, and atmospheric lifetime, thus impacting climate forcing. Aircraft-aerosol time-of-flight mass spectrometry (A-ATOFMS), which measures single-particle mixing state, was used to determine the fraction of organic and soot aerosols that are internally mixed and the variability of their mixing state in California during the Carbonaceous Aerosols and Radiative Effects Study (CARES) and the Research at the Nexus of Air Quality and Climate Change (CalNex) field campaigns in the late spring and early summer of 2010. Nearly 88% of all A-ATOFMS measured particles (100–1000 nm in diameter) were internally mixed with secondary species, with 96% and 75% of particles internally mixed with nitrate and/or sulfate in southern and northern California, respectively. Even though atmospheric particle composition in both regions was primarily influenced by urban sources, the mixing state was found to vary greatly, with nitrate and soot being the dominant species in southern California, and sulfate and organic carbon in northern California. Furthermore, mixing state varied temporally in northern California, with soot becoming the prevalent particle type towards the end of the study as regional pollution levels increased. The results from these studies demonstrate that the majority of ambient carbonaceous particles in California are internally mixed and are heavily influenced by secondary species that are most prevalent in the particular region. Based on these findings, considerations of regionally dominant sources and secondary species, as well as temporal variations of aerosol physical and optical properties, will be required to obtain more accurate predictions of the climate impacts of aerosol in California.

Camellia, comprising more than 200 species, is the type genus of the family Theaceae. Currently, the interspecies relationship of the economically important genus is still a matter of great debate and controversy. In an attempt to help settle this dispute using molecular phylogeny, we analyzed ITS sequences of 112 species of Camellia. The maximum parsimony and Bayesian trees grouped these species into eight major clades and four isolates. The current study supported the monophyly of sections Thea and Furfuracea, a merged section of Theopsis and Eriandra and the formation of section Oleifera by H, -t. Chang (Flora of Reipulicae Popularis Sinicae. Tomus 49 (3), Science Press, China). The study suggested the polyphyletic nature of the sections Camellia, Paracamellia, Pseudocamellia, and Tuberculata and the paraphyletic nature of the section Chrysantha but did not support the sectional status of the three small sections, Archecamellia, Piquetia, and Sterocarpus. We also discuss the results in terms of morphology, geographic distribution and the results from an earlier molecular phylogeny analysis.

Yellowfin goby, a fish native to East Asia, was first reported in northern California (San Francisco Bay) in 1963 and in southern California (Los Angeles Harbor) in 1979. Over the past 4 decades, it has spread to other northern and southern California estuaries, respectively. The docu- mented expansion of yellowfin goby in California provided an opportunity to study potential founder effects in a marine invasive fish by seeking evidence of reductions in mtDNA singleton haplotypes consistent with an expected loss of overall genetic diversity. We obtained samples of yellowfin goby from San Francisco Bay in northern California, from 2 small estuaries in southern California, and from Tokyo Bay, Japan, the presumed source population. The mtDNA control region was fully sequenced and analyzed for a total of 216 specimens, where the numbers of singleton haplotypes relative to the total number of haplotypes in each sample were compared to predictions from a regression analysis of singletons on total haplotypes. AMOVA comparisons among haplotype frequencies were also per- formed. Singleton haplotypes were significantly fewer than predicted among yellowfin goby of San Francisco Bay, indicating some loss of genetic diversity in that invasive population. Singletons were not significantly fewer than prediction among yellowfin goby of Tokyo Bay or of southern California. ΦST values were not significantly different between San Francisco and Tokyo bays, but were different between San Francisco Bay in northern California and southern California locations, suggesting separate introductions to California.

With the global increase of eutrophication and water quality deterioration, cyanobacterial blooms become more and more frequent around the world. Microcystis is the most frequent bloom-causing Cyanobacterium in freshwater bodies. Not only do its blooms emit foul odors and increase the cost of water treatment but also produce carcinogenic hepatotoxic microcystins. The taxonomy of Microcystis is the basis of water quality evaluation and management of harmful algae. However, the current taxonomy is mainly based on morphological criteria, and morphospecies do not necessarily reflect the genetic background of these notorious Microcystis strains. As the rapid economic development in the Pearl River Delta has caused river environment degradation, reservoirs have become the main source of drinking water in Guangdong Province; however, Microcystis blooms also plagued these reservoirs. In the present study, cpcBA–IGS of 30 Microcystis strains isolated from 12 reservoirs in Guangdong Province were sequenced, combined with selected 24 Microcystis strains of various geographic origin downloaded from GenBank, to determine their taxonomic status, phylogenetic affinities and geographic distributions. Sixty-seven variable sites and 50 parsimony-informative sites were found in 568 bp cpcBA–IGS region, 54 Microcystis strains were clustered into two major clades, of which clade two involved three strains of M. wesenbergii and one strain of M. marginata and clade 1 included the remaining species and strains. Strains of the same geographic origin did not necessarily cluster together, the same morphospecies may exhibit different genotypes, and the same genotype may represent various morphological characters, indicating that morphological criteria alone are not sufficient to determine species status of Microcystis and molecular markers-based taxonomy of Microcystis is feasible. Although genetic variation of cpcBA–IGS were not large yet in intrageneric level, more sensitive molecular methods such as AFLP and microsatellites are potentially suitable to resolve species status and evaluate the growth and decline of specific Microcystis blooms. Molecular markers will play an evermore important role in studies of Microcystis bloom.

The yellow fever mosquito Aedes aegypti inhabits much of the tropical and subtropical world and is a primary vector of dengue, Zika, and chikungunya viruses. Breeding populations of A. aegypti were first reported in California (CA) in 2013. Initial genetic analyses using 12 microsatellites on collections from Northern CA in 2013 indicated the South Central US region as the likely source of the introduction. We expanded genetic analyses of CA A. aegypti by: (a) examining additional Northern CA samples and including samples from Southern CA, (b) including more southern US populations for comparison, and (c) genotyping a subset of samples at 15,698 SNPs. Major results are: (1) Northern and Southern CA populations are distinct. (2) Northern populations are more genetically diverse than Southern CA populations. (3) Northern and Southern CA groups were likely founded by two independent introductions which came from the South Central US and Southwest US/northern Mexico regions respectively. (4) Our genetic data suggest that the founding events giving rise to the Northern CA and Southern CA populations likely occurred before the populations were first recognized in 2013 and 2014, respectively. (5) A Northern CA population analyzed at multiple time-points (two years apart) is genetically stable, consistent with permanent in situ breeding. These results expand previous work on the origin of California A. aegypti with the novel finding that this species entered California on multiple occasions, likely some years before its initial detection. This work has implications for mosquito surveillance and vector control activities not only in California but also in other regions where the distribution of this invasive mosquito is expanding.

Phylogenetic analyses of nuclear ribosomal ITS and ETS sequences yield considerable improvements in our knowledge of relationships, character evolution, and biogeography in Meryta (Araliaceae). This genus comprises ca. 30 species, all of which share simple leaves and a dioecious sexual system, a unique combination in Araliaceae. Meryta is distributed widely across the Pacific, but each of its species is endemic to only one or a few islands. Previous phylogenetic studies have included only a very limited number of exemplars from Meryta, but have suggested that the genus is related to the Southwest Pacific clade of Schefflera within the larger Polyscias-Pseudopanax group of Araliaceae. Our data confirm this previous placement and provide evidence for the monophyly of Meryta. There is no support for the recognition of three segregate genera, Botryomeryta, Schizomeryta, and Strobilopanax. Within Meryta, we have identified two major clades, one that unites the species from Fiji and New Zealand (both o...

Phylogenetic and biogeographic relationships inferred from nuclear ITS and ETS sequences strongly supported the monophyly of Diplusodon. Four major clades were have been found, three of which are strongly correlated with endemism and are centered in the Espinhaço Range, the Plateau Goiano and the Chapada Diamantina. The fourth clade, designated Cerrado clade with species from all three centers of diversity as well as widely distributed species and several species of lower elevation Cerrado. Species with the most plesiomorphic features occur in the clades east of the São Francisco River, while the greatest morphological diversity is found in the Plateau Goiano. The crown node of the genus is estimated to date to the late Pliocene, likely diversifying in the campos rupestres, where most of the later Pleistocene speciation bursts also appear to have occurred.

Diplusodon is the second–largest genus of the Lythraceae with 103 species of shrubs or subshrubs endemic to the Cerrado Domain. Many species are narrow endemics, restricted to campos rupestres on quartzite rocks, while others are found in cerrado and, more rarely, in gallery, or dry forest margins. Phylogenetic relationships inferred from nuclear ITS and ETS sequences strongly support the monophyly of Diplusodon. We found four major clades, three of which are strongly correlated with endemism and are centered in the Espinhaço Range (CEP), the Plateau Goiano (PG) and the Chapada Diamantina (CD). The fourth clade was designated the Cerrado clade (C), containing species from all three centers of diversity as well as widely distributed species and several species of lower–elevation cerrado. Species with the most plesiomorphic features occur in the clades east of the São Francisco River (C, CEP, CD), while the greatest morphological diversity is found in the PG. The crown node of the genus is estimated to date to the late Pliocene, likely diversifying in the campos rupestres, where most of the later Pleistocene speciation bursts also appear to have occurred. These patterns of diversification in Diplusodon appear to agree with old stable landscapes (OSL) theory, where high levels of in situ speciation in islands of campo rupestre, possibly isolated by more intense fire regimes of the surrounding cerrado vegetation, resulted in accumulation of high numbers of microendemic species. However, the adaptability of the genus is evidenced by multiple dispersal events to lower elevation cerrado, several long–distance dispersals, notably in the C clade, and the presence, in several clades, of species found both in campo rupestre and cerrado habitats.

This paper presents the first molecular phylogeny of the genus Hemsleya using nuclear ITS and plastid trnH-psbA, rpl16, and trnL DNA sequences to examine the relationships among Hemsleya species. Phylogenetic relationships were elucidated using a combined analysis of all four datasets, however, the number of parsimony-informative characters was still insufficient to resolve all relationships. Parsimony and Bayesian trees were highly congruent. Twenty-three species of Hemsleya split into two major clades corresponding to two subgenera, i.e., subg. Graciliflorae and subg. Hemsleya. These results are partly in agreement with Li’s sectional classification. However, the molecular data are inconsistent with Li’s classification at the subsectional level. The molecular phylogeny revealed a striking overall correlation between the phylogenetic relationships of the species and their geographical distribution. The Kangdian ancient landmass could be the center of origin of the genus.