Another Origin of Coloniality in Volvocaleans: The Phylogenetic Position of Pyrobotrys Arnoldi (Spondylomoraceae,Volvocales)

ABSTRACT. Colonial volvocaleans (Chlorophyceae) are used as a standard model of multicellular evolution. However, the phylogenetic position of the colonial volvocalean family Spondylomoraceae has yet to be resolved. To examine this, the molecular phylogenies of Pyrobotrys stellata and Pyrobotrys squarrosa were analyzed using combined 18S rRNA, RUBISCO large subunit, and P700 chl a‐apoprotein A2 gene sequences. In the phylogenetic trees, Pyrobotrys belonged to the clade Caudivolvoxa and was not closely related to other colonial volvocalean flagellates. The results indicate that colony formation of Spondylomoraceae independently evolved from unicellular volvocaleans. The phylogenetic position of problematic “Pascherina tetras” SAG 159‐1 was also analyzed.     

Genetic differentiation between humpback whales (Megaptera novaeangliae) from Atlantic and Pacific breeding grounds of South America

Humpback whales wintering in tropical waters along the Atlantic and Pacific coasts of the South American continent are thought to represent distinct populations or “stocks.” Here we present the first analysis of genetic differentiation and estimates of gene flow between these breeding stocks, based on both mitochondrial DNA (mtDNA) control region sequences (465 bp) and 16 microsatellite loci from samples collected off Brazil (n = 277) and Colombia (n = 148), as well as feeding areas near the western Antarctic Peninsula (n = 86). We found significant differentiation between Brazilian and Colombian breeding grounds at both mtDNA (F_ST = 0.058) and microsatellite (F_ST = 0.011) markers and corroborated previous studies showing genetic similarity between humpbacks from Colombia and those from Antarctic Peninsula feeding areas. Estimates of long‐term gene flow between Brazil and Colombia were low to moderate, asymmetrical, and mostly mediated by males. Assignment procedures detected some cases of interchange and individuals of admixed ancestry between breeding grounds, indicating limited mixing of individuals between these stocks. Overall, results highlight the differentiation of humpback whale breeding populations with adjacent feeding grounds. This appears to be a remarkable example of fidelity to seasonal habitat in the absence of any contemporary barriers.     

THE “PARADOX” DIATOM BACILLARIA PAXILLIFER (BACILLARIOPHYTA) REVISITED1

Defined by its unique colonial locomotion, Bacillaria paxillifer (O. F. Müll.) Hendey was recognized as a single, pandemic species by many phycologists. However, reinvestigation of colonies from different habitats revealed three distinct groups: (A) brackish/freshwater, (B) marine littoral, and (C) marine planktonic taxa. Groups differed in colony and cell form, raphe flanges (RFs), shape and position of transapical ribs (Tr's), and morphogenesis. Linear‐shaped species were restricted to group A: Tr's thickened principally to the interior. Lanceolate forms were confined to groups B and C: valve formation proceeded from an internal base layer to the exterior. The planktonic species differed in the shape of its raphe slit, and the transformation of girdle bands (GBs) into “winglets.” Taxa also differed in chloroplast shape and number. All species formed motile colonies. Siblings adhered via elastic fibrils secreted through their raphe. Raphe ribs were held in position by siliceous clamps (fibulae), anchored in an extra pair of axial ribs (fibular ribs) parallel to the raphe ribs. This raphe system resembled that of Cylindrotheca rather than the “canal raphe” of Nitzschia. Many valves were asymmetric along the apical axis due to protruding RFs shuttling in a 1:1 ratio within a colony, but raphe slits were mirror images, as were the growth direction of fibulae and position of plastids, with pyrenoids tilted in the same direction. Species possessed four open GBs per epitheca; the third band invariably bore an internal, organic ridge to aid in adhesion of the plasmalemma during cleavage. The results suggested that these taxa are a natural phylogenetic group, requiring precise determination of their taxonomic position.     

EVIDENCE FOR TUBULAR MATING STRUCTURES INDUCED IN EACH MATING TYPE OF HETEROTHALLIC GONIUM PECTORALE (VOLVOCALES,CHLOROPHYTA)1

Gametes were induced separately in cultures of each mating type of the heterothallic, isogamous colonial volvocalean Gonium pectorale O. F. Müll. to examine the tubular mating structure (TMS) of both mating types plus and minus (plus and minus), referred to as “bilateral mating papillae.” Addition of dibutyryl cyclic adenosine monophosphate (DcAMP or db‐cAMP) and 3‐isobutyl‐1‐methylxanthine (IBMX) to approximately 3‐week‐old cultures of each mating type induced immediate release of naked gametes from the cell walls. Both plus and minus gametes formed a TMS in the anterior region of the protoplasts. Accumulation of actin was visualized by antibody staining in the TMS of both mating types as occurs in the TMS (fertilization tubule) of the plus gametes of the unicellular volvocalean Chlamydomonas reinhardtii P. A. Dang. Induction of naked gametes with a TMS in each mating type will be useful for future cell biological and evolutionary studies of the isogametes of colonial volvocalean algae.     

Role of Cell Hydrophobicity on Colony Formation in Microcystis (Cyanobacteria)

Colony formation is highly import ant for the competitive advantage of the cyanobacterium Microcystis over other phytoplankton species. The laboratory‐grown colonial Microcystis strains isolated from Lake Taihu (China) maintained colonial forms under the low light condition (10 μE m^–2 s^–1). The cell surface hydrophobicities of the Microcystis colonies were measured by cyanobacterial adherence to xylene in comparison with unicellular Microcystis strains. The cells of the tested colonial strains were all hydrophobic, while the cells of the tested unicellular strains were all hydrophilic. Incubation under the higher light condition (75 μE m^–2 s^–1) leaded to the significant decrease in the cell hydrophobicities of the colonial Microcystis and the transition from colonial forms to unicellular forms. These findings indicated that the cell hydrophobicity of Microcystis may play a role in cell‐cell adherence and colony formation. Phosphate‐limitation, nitrate‐limitation and pH did not affect cell hydrophobicities of colonial Microcystis. Treatment with proteolytic enzymes had no effect on the cell hydrophobicity, indicating that cell surface proteins did not contribute to high cell hydrophobicity. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

A SYSTEMATIC REVISION OF PHYLLANTHUS SUBSECTION URINARIA (EUPHORBIACEAE)

The examination of several taxa from various tropical regions of the world, previously classified as Phyllanthus urinaria L., indicates that they do not belong to a single species. On the basis of morphology, cytology, genetics, and biometry, a new classification is presented in which the collective species P. urinaria, or “urinaria complex,” is elevated to the subsection level: Phyllanthus subsection Urinaria. Within the subsection, two subgroups may be recognized on the basis of seed coat ornamentation. Each of these lines is represented by two species which differ from each other in chromosome number: P. embergeri nov. spec. (2n = 100) and P. nozeranii nov. spec. (2n = 50) in the “spiraled” line, P. hookeri Muell. Arg. (2n = 100) and P. urinaria L. (2n = 50) in the “radiated” line. In the latter species, which has undergone diversification, two subspecies may be distinguished: P. urinaria urinaria and P. urinaria nudicarpus subspec. nova.     

Maternal feeding strategies, child eating behaviors, and child BMI in low-income African-American preschoolers

Objective: To test the hypothesis that low‐income African‐American preschool children would have a higher BMI if their mothers reported greater “restriction” and “control” in feeding and if mothers reported that children showed greater “food responsiveness” and “desire to drink.” In addition, to test whether higher maternal “pressure to eat” would be associated with lower child BMI. Research Methods and Procedures: A questionnaire was completed by 296 low‐income African‐American mothers of preschool children. It assessed three constructs on maternal feeding strategies (“restriction,” “pressure to eat,” and “control”) and two on child eating behaviors (“food responsiveness” and “desire to drink”). Children's BMI was measured, and mothers’ BMI was self‐reported. Results: The mean (standard deviation) BMI z‐score of the children was 0.34 (1.5), and 44% of the mothers were obese (BMI ≥30 kg/m²). Only maternal “pressure to eat” had a significant overall association with child BMI z‐score (r = ?0.16, p < 0.01). Both maternal “restriction” and “control” were positively associated with children's BMI z‐score in the case of obese mothers (r = 0.20, p = 0.03 and r = 0.24, p = 0.007, respectively), but this was not so in the case of non‐obese mothers (r = ?0.16, p = 0.05 and r = ?0.07, p = 0.39, respectively). Discussion: Among low‐income African Americans, the positive association between maternal restriction and control in feeding and their preschoolers’ BMI was limited to obese mothers. Relations between parent feeding strategies and child weight status in this population may differ on the basis of maternal weight status.     

Mating frequency, genetic structure, and sex ratio in the intermorphic female producing ant species Myrmecina nipponica

1. Myrmecina nipponica has two types of colonies: a queen colony type, in which the reproductive females are queens and new colonies are made by independent founding, and an intermorphic female colony type, in which reproductive females belong to a wingless intermediate morphology between queen and worker, and where colonies multiply through colonial budding. 2. The mating frequencies of reproductive females in both types indicate monoandry. The relatedness among nestmates in both types was almost 0.75, however relatedness between mother and daughter in intermorphic female colonies was slightly higher than that of queen colonies. 3. The sex ratio (corrected investment female ratio) was 0.70 at the population level, suggesting that the sex ratio is controlled by workers in this species, however the ratio differed greatly between the two types of colonies. Queen colonies (n = 37) had a female‐biased sex ratio of 0.77 while intermorphic female colonies (n = 33) had a ratio of 0.56. 4. Each reproductive intermorphic female was accompanied by an average of 2.9 workers (including virgin intermorphic females) in the colonial budding, and when the investment to those workers was added to the female investment, the sex ratio reached 0.81. 5. The frequency distribution of sex ratio was bimodal, with many colonies producing exclusively males or females, however mean estimated relatedness within colonies was almost 0.75. These data are inconsistent with the genetic variation hypothesis, which is one of the predominant hypotheses accounting for the between‐colony variation in sex ratio.     

Perception of the electromagnetic field emitted by a mobile phone

Electromagnetic sensibility refers to the ability to perceive the electromagnetic field (EMF) without necessarily developing health symptoms attributed to EMF exposure. A large sample of young healthy adults (n = 84) performed two forced‐choice tasks on the perception of the GSM mobile phone EMF (902 MHz pulsed at 217 Hz), “Was the field on?” and “Did the field change?” (3 conditions × 100 trials for each task, n = 600 trials in total). A monetary prize was announced for good performance (correct response rate ≥75%, n = 600 trials). The performance was no better than expected by chance, and thus none of the participants won the prize. Two participants showed extraordinary performance in one of the task conditions (“Was the field on?”, n = 100 trials), with correct response rates of 97% (P = 1.28 × 10^?25) and 94% (P = 9.40 × 10^?22), but they failed to replicate the result in the retest of six blocks of the same condition 1 month later. Six participants had reported being able to perceive the mobile phone EMF in the preliminary inquiry, but they performed no better than the others. This study provides empirical evidence against the existence of electromagnetic sensibility to the mobile phone EMF, demonstrating the necessity for replication in EMF studies. Bioelectromagnetics 29:154–159, 2008. © 2007 Wiley‐Liss, Inc.     

Phylogeographic structure in the chromosomally polymorphic rodent Cricetulus barabensis sensu lato (Mammalia,Cricetidae)

Striped hamsters (Cricetulus barabensis sensu lato) represent a complex of chromosomally distinct allopatric lineages/taxa of either species or subspecies rank. They are widely distributed across the steppes of eastern and central Palearctic. Phylogenetic analysis of cytochrome b gene sequences based on 496 specimens from 112 localities revealed five well‐supported lineages divergent at 2%–4%. Two of them correspond to “griseus” (2n = 22) and “pseudogriseus” (2n = 24) karyomorphs and are placed as sister taxa. The “barabensis” (2n = 20) karyomorph is represented by three other branches and appears non‐monophyletic. All mtDNA lineages are distributed allopatrically or parapatrically; no indications of gene flow between populations of different chromosomal races were found. The results of the molecular clock analysis suggest that the main lineages diverged in the late Middle Pleistocene. The inferred evolutionary scenario implies that the common ancestor of the recent lineages belonged to the 2n = 20 karyomorph and originated in the eastern part of the contemporary range.     

Multizooidal Budding in Parasmittina trispinosa (Johnston) (Bryozoa,Cheilostomata)

Two principally different wall types occur in the bryozoan colony: Exterior walls delimiting the super-individual, the colony, against its surroundings and interior walls dividing the body cavity of the colony thus defined into units which develop into sub-individuals, the zooids. In the gymnolaemate bryozoans generally, whether uniserial or multiserial, the longitudinal zooid walls are exterior, the transverse (proximal and distal) zooid walls interior ones. The radiating zooid rows grow apically to form “tubes” each surrounded by exterior walls but subdivided by interior (transverse) walls. The stenolaemate bryozoans show a contrasting mode of growth in which the colony swells in the distal direction to form one confluent cavity surrounded by an exterior wall but internally subdivided into zooids by interior walls. In the otherwise typical gymnolaemate Parasmittina trispinosa the growing edge is composed of a series of “giant buds” each surrounded by exterior walls on its lateral, frontal, basal and distal sides and forming an undifferentiated chamber usually 2–3 times as broad and 3 or more times as long as the final zooid. Its lumen is subdivided by interior walls into zooids 2–3, occasionally 4, in breadth. This type of zooid formation is therefore similar to the “common bud” or, better-named, “multizooidal budding” characteristic of the stenoleamates but has certainly evolved independently as a special modification of the usual gymnolaemate budding.     

MORPHOMETRIC CORRELATION PATTERNS OF ADULT BIRDS (FRINGILLIDAE: PASSERIFORMES AND COLUMBIFORMES) MIRROR THE EXPRESSION OF DEVELOPMENTAL CONTROL GENES

Stimulated by the rapid progress in developmental genetics, recent approaches to evolutionary theory focus on the interface function of developmental processes in the study of genotype-phenotype mapping. From this viewpoint, the main result of the present analysis is that the expression patterns of developmental control genes are reflected in the infraspecific correlation patterns of phenotypic characters in the adult stage. The study is based on 42 logarithmically scaled skeletal measurements of two avian clades, finches (43 species, n = 313) and pigeons (27 species, n = 219). First, for each clade an “observed correlation matrix” was calculated by computing a bias-reduced pooled-species correlation matrix based on the clade-specific pooled within-species variance-covariance matrix between measurements. Second, the expression domains of diverse developmental control genes, that is, Hox, Msx, Pax, Mhox, Shh, Bmp, and Gdf, in characters were represented by “theoretical matrices.” Finally, the observed and the theoretical matrices were compared by Mantel's test to test hypotheses about pattern similarities between phenotypic correlations and the expression of developmental control genes. Seventeen percent of the single matrix comparisons revealed significant (P ≤ 0.05) pattern correspondences in finches, whereas 63% were significant in pigeons. The multiple comparisons revealed correspondences at the highest significance level (P ≤ 0.001) in both clades and disclosed that 15% of the observed matrix patterns are explained in finches versus 22% in pigeons. Presumably, as finches have less pronounced correspondences between gene expression and phenotypic correlation, they are more derived than pigeons. Out of the significant single matrix comparisons, four correspondences are common to both clades: one of them is connected with the Gdf gene expression concerning limb length relations and also harmonizes with the dominant pattern within the infraspecific correlation matrices. The general implication is that the significant correspondences detected here between observed and theoretical matrices are based on a correspondence between phenotypic and genetic modules. Because the phenotypic modules are potential candidates for a direct impact of selection, the important role of genotype-phenotype mapping in molding the body plan becomes apparent.     

Flight Speed of Tethered Reticulitermes flavipes (Kollar) (Isoptera: Rhinotermitidae) Alates

Alates of the Eastern subterranean termite, Reticulitermes flavipes (Kollar) were collected over two flight seasons (2002 and 2004) and flown on flight mills. Data were collected to test if alate mass, colony origin, or gender influenced flight speed. Flight speed ranged from 3.14 to 69.12 cm s⁻¹ and the maximum distance flown by an alate was 458.3 m. Alate mass (P = 0.9406), gender (P = 0.3976), colony origin (P = 0.1244), and the interaction of gender and colony (P = 0.7093) did not significantly influence flight speed. Additionally, an electronic counting device was used to provide instantaneous flight speeds and allowed flight speed to be modeled during acceleration, cruising, and deceleration periods of flight. Mean (±SEM) flight speeds in 2004 were 20.64 (±2.21) cm s⁻¹ (n = 13) for males and 17.76 cm s⁻¹ (n = 1) for the single female flown, falling within the range of the 2002 values.     

A karyosystematic study of the genus Bellevalia Lapeyr. (Hyacinthaceae) in Greece

The genus Bellevalia is represented in Greece by eight taxa, three of which are endemic. Bellevalia brevipedicellata (2n = 8) and B. sitiaca (2n = 16) are restricted to the island of Kriti, while B. hyacinthoides (2n = 8, 12) is distributed in the Kiklades Islands, the central and southern mainland and the Ionian Islands. Four taxa, i.e. B. dubia subsp. boissieri (2n = 8), B. trifoliata (2n = 8), B. romana (2n = 8) and B. ciliata (2n = 8, 16) are Mediterranean elements. The presence of B. edirnensis (2n = 24) is reported as new for the Greek flora. New ploidy levels of three Bellevalia species (triplo‐, tetra‐ and hexaploids) are reported for the first time. The main morphological features, the chromosome numbers, the karyotype morphology, as well as the geographical distribution and further issues of taxonomy and conservation of all Bellevalia taxa in Greece are presented and discussed. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 157 , 723–739.     

Pediatricians’ Own Weight: Self‐perception,Misclassification, and Ease of Counseling

Objectives: Pediatricians underdiagnose overweight and feel ineffective at counseling. Given the relationship between physicians’ health and health habits and counseling behaviors, we sought to determine the 1) percentage of pediatricians who are overweight; 2) accuracy of pediatricians’ own weight status classification; and 3) relationship between weight self‐perception and perceived ease of obesity counseling. Research Methods and Procedures: This study was a cross‐sectional, mail survey of North Carolina pediatricians that queried about their weight status and ease of counseling. Accuracy of pediatricians’ self‐classification of weight status was compared with BMIs derived from self‐reported height and weight. Using logistic regression, controlling for potential confounding variables, we examined the association between weight perception and ease of counseling. Results: The unadjusted response rate was 62%, and the adjusted response rate was 71% (n = 355). Nearly one‐half (49%) of overweight pediatricians did not identify themselves as such. Men had greater adjusted odds of misclassifying overweight than women [odds ratio (OR), 3.61; 95% confidence interval (CI) = 1.81, 7.21]. Self‐classified “thin” pediatricians had nearly six times the odds of reporting more counseling difficulty as a result of their weight than “average” weight pediatricians (OR = 5.69; 95% CI = 2.30, 14.1), and self‐identified “overweight” pediatricians reported nearly four times as great counseling difficulty as “average” weight physicians (OR = 3.84; 95% CI = 1.11, 13.3), after adjustment for self‐reported BMI weight status and other potential confounders. Discussion: The roles that physician weight misclassification and self‐perception potentially play in influencing rates of obesity counseling warrant further research.     

Colony Structure in Flustra foliacea (Linnaeus) (Bryozoa,Chéilostomata)

Encrusting forms presumably represent the original mode of growth in the bryozoans. They usually exhibit a relatively low degree of colony integration. The numerous different erect colony types, certainly independently derived from this stage, show a higher degree of integration. Eventually forms arise with a strict pattern only little influenced by the environment. The Flustra foliacea colony holds an intermediate position in this respect. It forms an initial crust on a foreign substratum such as rock. The crust forms marginal lobes. The lobes collide two and two. The two components of each collision then rise back to back, owing to lack of space, into bilaminar fronds. The two zooid layers composing these erect branches and mutually encrusting the “auto-substratum” of their respective basal walls, grow much more rapidly than the initial crust on the “heterosubstratum” of the rock to finally comprise more than 95 % of the colony volume. The different rate of growth on “auto-” and “heterosubstratum” respectively is interpreted as indicating a preference for the “autosubstratum” and as the main force in the formation of erect branches. The Fl. foliacea case indicates one of the pathways from encrusting to erect colonies in the bryozoans. It is probably valid for at least some of the erect bilaminar colonies appearing in different parts of the bryozoan system.     

Collection of semen by manual stimulation and ejaculate characteristics of the black flying‐fox (Pteropus alecto)

Semen collection and preservation is the first step toward the development of an artificial insemination program in endangered Pteropus spp. Semen was collected by manual stimulation from a single “human‐habituated” P. alecto. Manual stimulation resulted in the successful collection of motile spermatozoa on 17 of 34 attempts. The semen had a pH of 8.2 (n=2). With the exception of volume, seminal characteristics (concentration, motility, acrosome and plasma membrane status) were similar to those collected previously by electro‐ejaculation. Zoo Biol 27:159–164, 2008. © 2008 Wiley‐Liss, Inc.     

Field trials of slow‐release synthetic lures for stoats (Mustela erminea) and ferrets (M. furo)

Abstract

Experimental field trials were used to compare the attractiveness to stoats (Mustela erminea) and ferrets (M. furo) of traps set with either a synthetic scent lure or with fresh food bait. One lure, containing 2‐n‐propylthietane, effectively attracted as many ferrets as did rabbit meat bait. Fewer stoats were caught with this lure than with egg bait. Made up in a slow‐release formulation in “plastic rope”, the lure remained attractive to ferrets for at least 2 weeks under sunny field conditions. Traps containing a second lure, 3‐n‐propyl‐l,2‐dithiolane, were less successful at catching both mustelid species than those containing fresh food baits. The scent lures were not attractive to non‐target species, but neither did they deter some species.     

CHROMOSOME CYTOLOGY OF EUCHARIS,CALIPHRURIA, AND URCEOLINA (AMARYLLIDACEAE)

Karyotypes are presented for 19 taxa of Eucharis, Caliphruria, and Urceolina, a monophyletic group of Andean Amaryllidaceae within “infrafamily” Pancratioidinae Traub. All three genera are characterized by 2n = 46, the most common somatic number occurring in the “infrafamily.” Incidences of polyploidy are low. Only two tetraploid (2n = 92) species of Eucharis are so far known, E. bouchei and E. bonplandii, the northernmost species of E. subg. Eucharis. The 2n = 68 karyotype of E. amazonica is interpreted as triploid-derived (3x – 1). Chromosomal heteromorphism is reported for C. subedentata. Karyotype data is analyzed with principal component analysis and unweighted pairgroup cluster analysis. In a number of cases, phenetic relationships among the karyotypes correlate with phenetic and cladistic relationships based on morphological data. Karyotype evolution among the three genera is discussed in the context of classical theories of karyotypic symmetry. Stability of chromosome number in Eucharis and related genera suggests that chromosomal evolution has proceeded via nonreciprocal interchanges between chromosomes and infrachromosomal structural change. In at least one case (E. bakeriana), rapid sympatric speciation may have been vectored by chromosomal change.     

BIOSYSTEMATIC INVESTIGATIONS IN SOUTH FLORIDA POPULATIONS OF RUELLIA (ACANTHACEAE)

Relationships of the putative Ruellia species, R. caroliniensis, R. ciliosa, R. heteromorpha, and R. succulenta were analyzed by population sampling, investigation of chromosome numbers, garden transplants, and hybridization experiments. Character data from 25 local, Florida populations and from transplants were evaluated. Some interfertility of these “taxa” was demonstrated, as was some interfertility with other species occurring in the eastern United States. Chromosome numbers are n = 17 and 2n = 34. The effect of different breeding systems on population structure is discussed. Total evidence suggests that the 4 “taxa” in question be considered ecological races of a single species widespread in the eastern United States, namely R. caroliniensis.