Possible Role of Mother-Daughter Vocal Interactions on the Development of Species-Specific Song in Gibbons

Mother-infant vocal interactions play a crucial role in the development of human language. However, comparatively little is known about the maternal role during vocal development in nonhuman primates. Here, we report the first evidence of mother-daughter vocal interactions contributing to vocal development in gibbons, a singing and monogamous ape species. Gibbons are well known for their species-specific duets sung between mates, yet little is known about the role of intergenerational duets in gibbon song development. We observed singing interactions between free-ranging mothers and their sub-adult daughters prior to emigration. Daughters sang simultaneously with their mothers at different rates. First, we observed significant acoustic variation between daughters. Co-singing rates between mother and daughter were negatively correlated with the temporal precision of the song’s synchronization. In addition, songs of daughters who co-sang less with their mothers were acoustically more similar to the maternal song than any other adult female’s song. All variables have been reported to be influenced by social relationships of pairs. Therefore those correlations would be mediated by mother-daughter social relationship, which would be modifiable in daughter’s development. Here we hypothesized that daughters who co-sing less often, well-synchronize, and converge acoustically with the maternal acoustic pattern would be at a more advanced stage of social independence in sub-adult females prior to emigration. Second, we observed acoustic matching between mothers and daughters when co-singing, suggesting short-term vocal flexibility. Third, we found that mothers adjusted songs to a more stereotyped pattern when co-singing than when singing alone. This vocal adjustment was stronger for mothers with daughters who co-sang less. These results indicate the presence of socially mediated vocal flexibility in gibbon sub-adults and adults, and that mother-daughter co-singing interactions may enhance vocal development. More comparative work, notably longitudinal and experimental, is now needed to clarify maternal roles during song development.     

The Ethylene-insensitive sickle mutant of Medicago truncatula shows altered auxin transport regulation during nodulation

We studied the ethylene-insensitive, hypernodulating mutant, sickle (skl), to investigate the interaction of ethylene with auxin transport during root nodulation in Medicago truncatula. Grafting experiments demonstrated that hypernodulation in skl is root controlled. Long distance transport of auxin from shoot to root was reduced by rhizobia after 24 h in wild type but not in skl. Similarly, the ethylene precursor 1-amino cyclopropane-1-carboxylic acid inhibited auxin transport in wild type but not in skl. Auxin transport at the nodule initiation zone was significantly reduced by rhizobia after 4 h in both wild type and skl. After 24 h, auxin transport significantly increased at the nodule initiation zone in skl compared to wild type, accompanied by an increase in the expression of the MtPIN1 and MtPIN2 (pin formed) auxin efflux transporters. Response assays to different auxins did not show any phenotype that would suggest a defect of auxin uptake in skl. The auxin transport inhibitor N-1-naphthylphtalamic acid inhibited nodulation in wild type but not skl, even though N-1-naphthylphtalamic acid still inhibited auxin transport in skl. Our results suggest that ethylene signaling modulates auxin transport regulation at certain stages of nodule development, partially through PIN gene expression, and that an increase in auxin transport relative to the wild type is correlated with higher nodule numbers. We also discuss the regulation of auxin transport in skl in comparison to previously published data on the autoregulation mutant, super numerary nodules (van Noorden et al., 2006).     

Parentage-based pedigree reconstruction reveals female matrilineal clusters and male-biased dispersal in nongregarious Asian great apes, the Bornean orang-utans (Pongo pygmaeus)

Philopatry and sex-biased dispersal have a strong influence on population genetic structure, so the study of species dispersal patterns and evolutionary mechanisms shaping them are of great interest. Particularly nongregarious mammalian species present an underexplored field of study: despite their lower levels of sociality compared to group-living species, interactions among individuals do occur, providing opportunities for cryptic kin selection. Among the least gregarious primates are orang-utans (genus: Pongo), in which preferential associations among females have nevertheless been observed, but for which the presence of kin structures was so far unresolved because of the equivocal results of previous genetic studies. To clarify relatedness and dispersal patterns in orang-utans, we examined the largest longitudinal set of individuals with combined genetic, spatial and behavioural data. We found that males had significantly higher mitochondrial DNA (mtDNA) variation and more unique haplotypes, thus underscoring their different maternal ancestries compared to females. Moreover, pedigree reconstruction based on 24 highly polymorphic microsatellite markers and mtDNA haplotypes demonstrated the presence of three matrilineal clusters of generally highly related females with substantially overlapping ranges. In orang-utans and possibly other nongregarious species, comparing average biparental relatedness (r) of males and females to infer sex-biased dispersal is extremely problematic. This is because the opportunistic sampling regime frequently employed in nongregarious species, combined with overlapping space use of distinct matrilineal clusters, leads to a strong downward bias when mtDNA lineage membership is ignored. Thus, in nongregarious species, correct inferences of dispersal can only be achieved by combining several genetic approaches with detailed spatial information.     

The Siak, a tropical black water river in central Sumatra on the verge of anoxia

The Siak is a black water river in central Sumatra, Indonesia, which owes its brown color to dissolved organic matter (DOM) leached from surrounding, heavily disturbed peat soils. The dissolved organic carbon (DOC) concentrations measured during five expeditions in the Siak between 2004 and 2006 are among the highest reported world wide. The DOM decomposition appeared to be a main factor influencing the oxygen concentration in the Siak which showed values down to 12 μmol l⁻¹. Results derived from a box-diffusion model indicated that in addition to the DOC concentration and the associated DOM decomposition the water-depth also plays a crucial role in regulating the oxygen levels in the river because of its impact on the turbulence in the aquatic boundary layer and the surface/volume ratio of water in the river. Model results imply furthermore that a reduced water-depth could counteract an increased oxygen consumption caused by an enhanced DOM leaching during the transition from dry to wet periods. This buffer mechanism seems to be close to its limits as indicated by sensitivity studies which showed in line with measured data that an increase of the DOC concentrations by ~15% could already lead to anoxic conditions in the Siak. This emphasizes the sensitivity of the Siak against further peat soil degradation, which is assumed to increase DOC concentrations in the rivers.     

Hyperinduction of pectate lyase in Dickeya chrysanthemi EC16 by plant-derived sugars

Pectate lyase (Pel) synthesis in Dickeya chrysanthemi has been reported to be hyperinduced in planta and also in the medium containing plant extract in addition to polygalacturonate. In this study, the major components of Pel-hyperinducing fractions were found to be glucose, fructose, and sucrose by TLC and NMR. From the analysis of the sugars and their derivatives, it was found that acyclic d-hexoses with the trans relationship between C-3 and C-5 hydroxyl groups were found to be basic structure required for hyperinducing the expression of a major isozyme in infected plants (i.e. pelE). From the fact that some non-metabolizable sugars such as 2-deoxy-d-glucose and d-fucose could lead to hyperinduction and that the hyperinduction was observed only in the medium containing low concentration (<0.25%) but not higher of the sugars was added, these sugars may be considered to participate in hyperinduction as the signal rather than through their metabolism.     

Characterization and pharmacological properties of in vitro propagated clones of <Emphasis Type="Italic">Echinacea tennesseensis</Emphasis> (Beadle) Small

Tissue culture techniques have been used to establish and maintain a repository of medicinal Echinacea. In vitro clones obtained from hypocotyls of germinated seeds, varied macroscopically, microscopically and exhibited variation in immune enhancing activity. Two in vitro produced clones of Echinacea tennesseensis (Beadle) Small (ETN 03 and ETN 11) were identified as high and low activity based on the activation of human monocytes. Phenotypic analyses of ETN 03 and ETN 11 clones were done using AFLP (Amplified Fragment Length Polymorphism) assay. Results of the AFLP assay revealed that no mutation has occurred during in vitro multiplication, storage, and acclimatization into soil. Plants of ETN 03, ETN 11 clones were cultivated for two growing seasons. Extracts of their dry leaves and roots exhibited immune enhancing activity; however, the variation in activity noticed between clones during micropropagation diminished and was no longer statistically relevant.     

Taxonomy of reproductive Nereididae (Annelida) in multispecies swarms at Ambon Island,Indonesia

Multispecies, or mass, spawning of different invertebrate species is well known for coral reef systems; however, incidences involving polychaetes are poorly documented. In this study we report on mass swarming, prior to spawning, of Nereididae at Ambon Island, Maluku, on three occasions: in 1866, inferred from an historical sample deposited in Naturalis, Leiden, and in March, 2009 and 2014, based on newly collected samples. The 2009 and 2014 events co-occurred with spawning of other polychaetes, known locally as wawo and including the widespread Indo-Pacific eunicid, Palola viridis (Gray in Stair). Ten species of reproductive Nereididae are described, including Composetia marmorata (Horst) new combination, formerly Ceratonereis marmorata; epitokous modifications are described for both sexes of each species including taxonomically important features such as body colour and number of pre-natatory chaetigers. Three distinct types of natatory region morphologies are recognized, which appear to characterise groups of genera. The ten new records brings to 13 the total number of nereidid species known to undergo mass swarming at Ambon Island; a key to the 13 species is provided. Species composition varies slightly between the three time periods: four species were common between all three periods, five species were in common between 1866 and 2014, and four species were in common between 1995 and 2009/14. Two species of Neanthes and one of Nereis are identified as potentially new and will be described in subsequent papers.     

Activities of plant cell wall-degrading enzymes by bacterial soft rot of orchid

Soft rot by bacterial pathogens is one of the most widespread and destructive diseases on various plants including orchids throughout the world. The pathogenicity of the pathogens is reported to be mainly determined by massive production of plant cell wall-degrading enzymes (PCDE). In the previous work, we have isolated 20 isolates of bacterial soft rot from orchids collected in Yogyakarta Special Region and West Java province, Indonesia. In this study, we further confirmed them as pathogens by hypersensitive reaction assay on tobacco leaves followed by pathogenicity test on Phalaenopsis sp. The production of four major PCDE by qualitative plate assays including pectate lyase, polygalacturonase, cellulase and protease was also evaluated. Even though all the isolates were able to initiate soft rot symptom, our results showed two distinct groups which clustered as producing and non-producing PCDE. The 16S rDNA analysis revealed that the isolates belonged to the genera Pectobacterium, Klebsiella, Serratia, Enterobacter, Citrobacter, Providencia and Pseudomonas.     

Plant response and huanglongbing disease development against heat treatments on ‘Siam Purworejo’ (Citrus nobilis (Lour)) and ‘Nambangan’ (C. maxima (Burm.) Merr.) under field condition

Huanglongbing is known as a destructive disease in citrus production. Investigation on plant response and development of huanglongbing disease against heat treatment on ‘Siam Purworejo’ (Citrus nobilis (Lour)) and ‘Nambangan’ (C. maxima (Burm.) Merr.) was done. High-temperature treatment was applied by covering plants with an enclosed screen. The treatment plant has three types of CLas pathogen infection status. The result showed that heat treatments could significantly increase new flushes. It was found that intensity of HLB infected plant decreased. The treatments effect on the proline level was dependent on cultivar, leaves age and HLB-infection status. Chlorophyll content of HLB infected plants increased due to high temperature. High-temperature increased Fe content in the artificially infected plant, whereas Zn contents increased in the leaves of infected plants by vector. ‘Nambangan’ had higher Fe content than ‘Siam Purworejo’ on uncovered plants. CLas bacteria still persisted in infected plant based on real-time PCR analysis.