Parthenogenetic development of dwarf surf dam,Mulinia lateralis,oocytes treated with polar body suppressing agents

Summary

Parthenogenesis following oocyte activation has been observed in a number of marine invertebrates, but the fate of parthenogenesis in bivalve mollusc embryos is unclear. We used the dwarf surf clam, Mulinia lateralis, to examine parthenogenetic development of KC1-activated oocytes using the polar body suppressing agents caffeine and heat or cytochalasin B. Development was followed by epifluorescence microscopy and flow-cytometric analysis using the DNA-specific fluorochrome DAPI. All agents suppressed polar body formation to some degree, putatively increasing the ploidy level and retaining a meiotic centrosome in the zygote; but the zygotes failed to develop normally. Failure of the zygotes to develop suggests that the meiotic centrosome is incapable of participating in mitosis in bivalves.     

THE COMMUNICATIVE SIGNIFICANCE OF TONALITY IN BIRDSONG: RESPONSES TO SONGS PRODUCED IN HELIUM

ABSTRACT

“Pure tones” are a distinctive acoustic feature of many birdsongs. Recent research on songbird vocal physiology suggests that such tonal sounds result from a coordinated interaction between the syrinx and a vocal filter, as demonstrated by the emergence of harmonic overtones when a bird sings in helium. To investigate the communicative significance of vocal tract filtration in the production of birdsong, we used field playback experiments to compare the responses of male swamp sparrows Melospiza georgiana to normal songs and those same songs recorded in helium. We also measured responses to pure tone songs that had been shifted upward in frequency to match the average spectra of those songs with added harmonics. Male sparrows were significantly more responsive to the playback of normal songs than to either helium songs with added harmonics or frequency- shifted pure tone songs. Songs with harmonics retained a high degree of salience, however. We conclude that explanations for the occurrence of tonal sounds in birdsongs must consider perceptual attributes of songs as communicative signals, as well as problems of song production and transmission.     

Noninvasive methodology for the sampling and extraction of DNA from free‐ranging Atlantic spotted dolphins (Stenella frontalis)

Genetic sampling and molecular investigations are important parts of studying wild populations. However, collecting tissues from free‐ranging animals can be difficult or impractical. This study develops a sampling and extraction protocol for template DNA from faecal material collected in a marine environment from small cetaceans. DNA was extracted from faecal material of free‐ranging Atlantic spotted dolphins (Stenella frontalis) and subsequently tested for its suitability in molecular investigations by amplifying both mitochondrial and nuclear DNA. The resulting mitochondrial sequences were found to closely match known S. frontalis haplotypes. Three microsatellite loci were amplified and fall within the expected size range for cetaceans. Mother and calf families previously assigned by observation were genetically confirmed using both mitochondrial haplotype and allele sharing between the mother and offspring. The protocol effectively collects and extracts dolphin DNA from faecal samples and enables species identification as well as confirmation of genetic relatedness and should be considered as a noninvasive alternative to current protocols.     

Survival of boll weevil （Coleoptera： Curculionidae） adults after feeding on pollens from various sources

The survival of overwintering boll weevil, Anthonomus grandis grandis （Boheman）, adults on non-cotton hosts in the Lower Rio Grande Valley （LRGV） of Texas was examined from 2001 to 2006. The success of the Boll Weevil Eradication Program, which was reintroduced into the LRGV in 2005, depends on controlling overwintering boll weevil populations. Laboratory studies were conducted using boll weevil adults that were captured in pheromone traps from September through March. The number of adults captured per trap declined significantly in the field from fall to the beginning of spring （3.5-7.0-fold）. The proportion of trapped males and females did not differ significantly. The mean weight of boll weevil adults captured in September was 13.3 mg, while those of captured adults from November to February were significantly lower and ranged from 6.7 to 7.8 mg. Our results show that boll weevil adults can feed on different plant pollens. The highest longevity occurred when adults were fed almond pollen or mixed pollens （72.6 days and 69.2 days, respectively） and the lowest when they fed on citrus pollen or a non-food source （9.7 days or 7.4 days, respectively）. The highest adult survival occurred on almond and mixed pollens [88.0%-97. 6% after 1st feeding period （10 days）, 78.0%-90.8% after 3rd feeding period （10 days）, 55. 0%-83.6% after 5th feeding period （10 days）, and 15.2%-32.4% after lOth feeding period （10 days）]. The lowest adult survival occurred on citrus pollen [52.0%-56.0% after 1st feeding period （10 days）, 13.3% after 3rd and 5th feeding periods （10 days）, and 0 after 6th feeding period （10 days）]. Pollen feeding is not a behavior restricted to adult boll weevils of a specific sex or physiological state. Understanding how boll weevil adults survive in the absence of cotton is important to ensure ultimate success of eradicating this pest in the subtropics.     

Delay and failure in treatment seeking after first onset of mental disorders in the World Health Organization's World Mental Health Survey Initiative

Data are presented on patterns of failure and delay in making initial treatment contact after first onset of a mental disorder in 15 countries in the World Health Organization (WHO)''s World Mental Health (WMH) Surveys. Representative face-to-face household surveys were conducted among 76,012 respondents aged 18 and older in Belgium, Colombia, France, Germany, Israel, Italy, Japan, Lebanon, Mexico, the Netherlands, New Zealand, Nigeria, People''s Republic of China (Beijing and Shanghai), Spain, and the United States. The WHO Composite International Diagnostic Interview (CIDI) was used to assess lifetime DSM-IV anxiety, mood, and substance use disorders. Ages of onset for individual disorders and ages of first treatment contact for each disorder were used to calculate the extent of failure and delay in initial help seeking. The proportion of lifetime cases making treatment contact in the year of disorder onset ranged from 0.8 to 36.4% for anxiety disorders, from 6.0 to 52.1% for mood disorders, and from 0.9 to 18.6% for substance use disorders. By 50 years, the proportion of lifetime cases making treatment contact ranged from 15.2 to 95.0% for anxiety disorders, from 7.9 to 98.6% for mood disorders, and from 19.8 to 86.1% for substance use disorders. Median delays among cases eventually making contact ranged from 3.0 to 30.0 years for anxiety disorders, from 1.0 to 14.0 years for mood disorders, and from 6.0 to 18.0 years for substance use disorders. Failure and delays in treatment seeking were generally greater in developing countries, older cohorts, men, and cases with earlier ages of onset. These results show that failure and delays in initial help seeking are pervasive problems worldwide. Interventions to ensure prompt initial treatment contacts are needed to reduce the global burdens and hazards of untreated mental disorders.     

Relationships Between Fire Response, Morphology, Root Anatomy and Starch Distribution in South-west Australian Epacridaceae

Selected epacrids (92 species in 15 genera) were examined withrespect to fire response type, morphology, root anatomy andstarch storage. Seeders, 75% of the species investigated, possesseda single main stem and a small root system with lateral rootswhich in most cases did not spread beyond the shoot canopy.Resprouter species were generally multi-stemmed with large lignotuberousroot stocks. Certain seeder and resprouter species were intermediatein form and showed small root systems and basally branched mainstems. Amounts of starch in roots of seeders (1.9±0.5mgstarch gd.wt per root) were much less than in resprouters (14.1±3.3)whereas amounts in shoots were similar (1.9±0.5 and 1.6±0.6mgstarch gd.wt per shoot, respectively). Starch storage in rootswas mostly confined to rays of xylem parenchyma and inter-rayxylem parenchyma and the greater storage capacity of resprouterswas generally due to broader rays. Growth zones in root xylemranged from clear, verifiable annual rings, as in many seederspecies, to indistinct growth zones, typical of many resprouterspecies. Shoot:root dry weight ratios were higher in seedersthan resprouters. The study suggests that speciation withinthe Epacridaceae into seeder and resprouter forms involved divergentdifferentiation in terms of morphology, shoot:root dry weightratio root storage of starch. Seeder; starch storage; growth rings; growth zones; south-west Australia; resprouter; Epacridaceae     

ANATOMY AND SYSTEMATIC PLACEMENT OF SAYELLA LAEVIGATA (GASTROPODA: PYRAMIDELLIDAE: SAYELLINAE)

The ectoparasitic snail Sayella laevigata was first describedby Orbigny (1842) and first placed in the genus Sayella by Odé (1994) without discussion. This study provides justificationfor this assignment to the genus Sayella Dall, 1885 and to the subfamilySayellinae Wise, 1996. Sayella laevigata possesses an elongatepenis, with subapical swelling tapering to a short terminalnipple, that is characteristic of the genus.