Publications

Drosophila melanogaster has a robust circadian clock, which drives a rhythmic behavior pattern: locomotor activity increases in the morning shortly before lights on (M peak) and in the evening shortly before lights off (E peak). This pattern is controlled by ~75 pairs of circadian neurons in the Drosophila brain. One key group of neurons is the M-cells (PDF(+) large and small LNvs), which control the M peak. A second key group is the E-cells, consisting of four LNds and the fifth small LNv, which control the E peak. Recent studies show that the M-cells have a second role in addition to controlling the M peak; they communicate with the E-cells (as well as DN1s) to affect their timing, probably as a function of environmental conditions (Guo, Cerullo, Chen, & Rosbash, 2014). To learn about molecules within the M-cells important for their functional roles, we have adapted methods to manually sort fluorescent protein-expressing neurons of interest from dissociated Drosophila brains. We isolated mRNA and miRNA from sorted M-cells and amplified the resulting DNAs to create deep-sequencing libraries. Visual inspection of the libraries illustrates that they are specific to a particular neuronal subgroup; M-cell libraries contain timeless and dopaminergic cell libraries contain ple/TH. Using these data, it is possible to identify cycling transcripts as well as many mRNAs and miRNAs specific to or enriched in particular groups of neurons.

Recent studies have shown that under specific conditions such as high sample sizes and Hardy-Weinberg equilibrium, bone marrow donor registry data can be used to describe HLA molecular variation across a specific geographic area, thus providing excellent data sets to infer human migrations history. The province of Quebec is known to have experienced a complex history of settlement, characterized by multiple migrations and demographic changes. We thus analysed the data of more than 13 000 unrelated individuals acting as volunteer bone marrow donors who were molecularly typed for HLA-A, B and DRB1 polymorphisms in the Héma-Quebec registry. HLA allelic and haplotypic frequencies were estimated and compared among regions. The results indicate that, despite an overall low genetic diversity in Quebec, genetic variation is correlated with geography, compatible with isolation-by-distance across the province. However, some localities also harbour contrasting genetic profiles, that is a highly diversified genetic pool in the two main urban centres (Montréal and Laval) and a more pronounced genetic divergence of two specific regions characterized by a peculiar peopling history (Saguenay-Lac-St-Jean and Gaspésie-Îles-De-La-Madeleine). In agreement with other independent molecular markers, the observations based on HLA data thus account for the main demographic mechanisms that shaped the genetic structure of the present day Quebecer population. In addition, the detailed analysis of the Héma-Quebec registry provides key genetic information on which an efficient bone marrow transplantation recruitment strategy can be settled.

Foraminifera remain poorly studied from deep-sea sediment settings, although they often dominate meiofaunal communities and represent an important part of the functional deep-sea diversity. Moreover, there is a striking gap in our knowledge of deep-sea Foraminifera since most of the foraminiferal diversity corresponds to single-chambered monothalamids displaying inconspicuous morphologies. The previous expeditions suggest that the foraminiferal biomass is large in the Kuril–Kamchatka Trench area, including many macrofaunal-size xenophyophoreans and komokiaceans. However, the on-site foraminiferal diversity remains poorly described and was never genetically examined. During the KuramBio expedition, we collected over 1400 specimens representing all major foraminiferal groups, focusing on monothalamids and particularly komokiaceans. From the deep-sea sediments, using four different sampling gears, we sorted, identified and photographed single specimens for DNA (or RNA) extraction. The material we report here will be used in our ongoing research on estimation and visualisation of the diversity of deep-sea monothalamous foraminifera and enigmatic taxa such as the komokiaceans, the origin of which is yet to be determined.

Although sociability offers many advantages, a major drawback is the increased risk of exposure to contagious pathogens, like parasites, viruses, or bacteria. Social species have evolved various behavioral strategies reducing the probability of pathogen exposure. In rodents, sick conspecific avoidance can be induced by olfactory cues emitted by parasitized or infected conspecifics. The neural circuits involved in this behavior remain largely unknown. We observed that olfactory cues present in bodily products of mice in an acute inflammatory state or infected with a viral pathogen are aversive to conspecifics. We found that these chemical signals trigger neural activity in the vomeronasal system, an olfactory subsystem controlling various innate behaviors. Supporting the functional relevance of these observations, we show that preference toward healthy individuals is abolished in mice with impaired vomeronasal function. These findings reveal a novel function played by the vomeronasal system.

The knowledge of the diversity of haemosporidian parasites is of primary importance as their representatives include agents of bird malaria. We investigated the occurrence of Haemoproteus spp. and Plasmodium spp. in bird populations from a single locality in the State of Selangor, Peninsular Malaysia, and report on the parasite prevalence of the two genera. A combination of methods (molecular and morphological) was used for detecting these parasites. Seventy-nine bird individuals were caught using mist-nets in July and August 2010 at Gombak Field Station of the University of Malaya, Kuala Lumpur. In total, 23 birds were identified as positive for Haemoproteus or Plasmodium infection and one individual was recognized as carrying mixed infection. The total prevalence of haemosporidians in the collected samples was 30.3%. Infections with parasites of the genus Haemoproteus were predominant compared to those of the genus Plasmodium. In total, 10 new cyt b lineages of Haemoproteus spp. and 3 new cyt b lineages of Plasmodium spp. were recorded in this study. From all recorded haemosporidian lineages (16 in total), 3 were known from previous studies - hCOLL2, hYWT2 and pNILSUN1. Two of them are linked with their corresponding morphospecies - Haemoproteus pallidus (COLL2) and Haemoproteus motacillae (YWT2). The morphological analysis in the present study confirmed the results obtained by the PCR method relative to prevalence, with 25.3% total prevalence of Haemoproteus and Plasmodium parasites. The intensities of infection varied between 0.01% and 19%. Most infections were light, with intensities below 0.1%. The present study is the first molecular survey of the protozoan blood parasites of the order Haemosporida recorded in Malaysia.

A small planispiral rotaliid, Nonion? niveum, was described by Lafrenz from the Eemian (upper Pleistocene) of the Baltic Sea. Since then, the species has several times been attributed to other genera (Haynesina, Protelphidium), resulting in taxonomic confusion. Recently, a morphologically identical foraminifer has been found in the White Sea, which is the first documented occurrence of the species from this area. In-depth investigation of its test morphology revealed that the species has features common to modern Haynesina representatives and particularly to the extinct Paleogene species Protelphidium hofkeri. This was especially evident in the architecture of the umbilical area. With the help of a comparative morphological study of several other elphidiids, the species in question was attributed to the genus Protelphidium, as its only living member and with the necessary emendation of the diagnosis. We believe that the redescription of Protelphidium niveum helps to clarify the taxonomy of the basal “lower” elphidiids by coupling the revision of morphological features with molecular data.

Based on a re-examination of type-specimens of Filaria hyalina von Linstow, 1890 from Sorex araneus L. (Mammalia: Soricidae) and morphological studies (light and scanning electron microscopy) of specimens collected from the same host species in Bulgaria and previously identified as Stammerinema rhopalocephalum (Sołtys, 1952), both these forms are considered to be conspecific. Accordingly, F. hyalina is transferred to the genus Stammerinema Osche, 1955 as Stammerinema hyalinum n. comb. and the species originally described as Synhimantus rhopalocephalus Sołtys, 1952 is considered its junior synonym.

Morphological examination of novel specimens of paruterinid cestodes from passerine birds from Brazil and Chile and of museum specimens from Paraguay revealed two new species: Anonchotaenia prolixa sp. n. from Elaenia albiceps chilensis Hellmayr from Chile, and Anonchotaenia vaslata sp. n. from Tyrannus melancholicus (Vieillot) (type host) and Myiodynastes maculatus (Statius Muller) from Paraguay. The generic diagnosis of Anonchotaenia Conn, 1900 is amended, prompted by the presence of the armed cirrus and the elongated cirrus sac of A. prolixa. Two species were redescribed: Anonchotaenia brasiliensis Fuhrmann, 1908 from Tachyphonus coronatus (Vieillot) and Thraupis cyanoptera (Vieillot) (new host records) from Brazil, and Thraupis sayaca (Linnaeus) and Volatinia jacarina (Linnaeus) from Paraguay (new host and geographic records); and Anonchotaenia macrocephala Fuhrmann, 1908 from Tachycineta leucorrhoa (Vieillot) (new host record) from Brazil, Tachycineta meyeni (Cabanis) from Chile (new host and geographic record) and Stelgidopteryx ruficollis (Vieillot) from Paraguay (new host and geographic record). Scanning electron microscopy of A. brasiliensis and A. macrocephala revealed less microthrix variation than has been reported for other cyclophyllidean taxa. Sequence data were generated for nuclear ssr- and lsr-DNA and mitochondrial rrnL and cox1 for A. prolixa, A. brasiliensis, and A. macrocephala. Maximum likelihood and Bayesian inference analyses supported each species as distinct, but revealed cryptic diversity among A. brasiliensis specimens from different host families. New host records of A. brasiliensis and A. macrocephala prompted a formal assessment of host specificity. Anonchotaenia prolixa was found to be oioxenous (HS(S) = 0), A. vaslata and A. macrocephala were found to be metastenoxenous (HS(S) = 3.000 and 3.302, respectively), whereas A. brasiliensis was found to be euryxenous (HS(S) = 5.876). Anonchotaenia brasiliensis has been found parasitising several species of different passerine families that participate in mixed-species foraging flocks in the Atlantic Forest. A diversity of species of other families join these flocks and are among the substantial number of South American passerine species yet to be examined for cestodes.

In recent decades, a profound conceptual transformation has occurred comprising different areas of biological research, leading to a novel understanding of life processes as much more dynamic and changeable. Discoveries in plants and animals, as well as novel experimental approaches, have prompted the research community to reconsider established concepts and paradigms. This development was taken as an incentive to organise a workshop in May 2014 at the Academia Nazionale dei Lincei in Rome. There, experts on epigenetics, regeneration, neuroplasticity, and computational biology, using different animal and plant models, presented their insights on important aspects of a dynamic architecture of life, which comprises all organisational levels of the organism. Their work demonstrates that a dynamic nature of life persists during the entire existence of the organism and permits animals and plants not only to fine-tune their response to particular environmental demands during development, but underlies their continuous capacity to do so. Here, a synthesis of the different findings and their relevance for biological thinking is presented.

[This corrects the article DOI: 10.4137/EBO.S33488.].