The genomes of two key bumblebee species with primitive eusocial organization

Background: The shift from solitary to social behavior is one of the major evolutionary transitions. Primitively eusocial bumblebees are uniquely placed to illuminate the evolution of highly eusocial insect societies. Bumblebees are also invaluable natural and agricultural pollinators, and there is widespread concern over recent population declines in some species. High-quality genomic data will inform key aspects of bumblebee biology, including susceptibility to implicated population viability threats. Results: We report the high quality draft genome sequences of Bombus terrestris and Bombus impatiens, two ecologically dominant bumblebees and widely utilized study species. Comparing these new genomes to those of the highly eusocial honeybee Apis mellifera and other Hymenoptera, we identify deeply conserved similarities, as well as novelties key to the biology of these organisms. Some honeybee genome features thought to underpin advanced eusociality are also present in bumblebees, indicating an earlier evolution in the bee lineage. Xenobiotic detoxification and immune genes are similarly depauperate in bumblebees and honeybees, and multiple categories of genes linked to social organization, including development and behavior, show high conservation. Key differences identified include a bias in bumblebee chemoreception towards gustation from olfaction, and striking differences in microRNAs, potentially responsible for gene regulation underlying social and other traits. Conclusions: These two bumblebee genomes provide a foundation for post-genomic research on these key pollinators and insect societies. Overall, gene repertoires suggest that the route to advanced eusociality in bees was mediated by many small changes in many genes and processes, and not by notable expansion or depauperation

25th annual computational neuroscience meeting: CNS-2016

The same neuron may play different functional roles in the neural circuits to which it belongs. For example, neurons in the Tritonia pedal ganglia may participate in variable phases of the swim motor rhythms [1]. While such neuronal functional variability is likely to play a major role the delivery of the functionality of neural systems, it is difficult to study it in most nervous systems. We work on the pyloric rhythm network of the crustacean stomatogastric ganglion (STG) [2]. Typically network models of the STG treat neurons of the same functional type as a single model neuron (e.g. PD neurons), assuming the same conductance parameters for these neurons and implying their synchronous firing [3, 4]. However, simultaneous recording of PD neurons shows differences between the timings of spikes of these neurons. This may indicate functional variability of these neurons. Here we modelled separately the two PD neurons of the STG in a multi-neuron model of the pyloric network. Our neuron models comply with known correlations between conductance parameters of ionic currents. Our results reproduce the experimental finding of increasing spike time distance between spikes originating from the two model PD neurons during their synchronised burst phase. The PD neuron with the larger calcium conductance generates its spikes before the other PD neuron. Larger potassium conductance values in the follower neuron imply longer delays between spikes, see Fig. 17.Neuromodulators change the conductance parameters of neurons and maintain the ratios of these parameters [5]. Our results show that such changes may shift the individual contribution of two PD neurons to the PD-phase of the pyloric rhythm altering their functionality within this rhythm. Our work paves the way towards an accessible experimental and computational framework for the analysis of the mechanisms and impact of functional variability of neurons within the neural circuits to which they belong

A Penile Spine/Vibrissa Enhancer Sequence Is Missing in Modern and Extinct Humans but Is Retained in Multiple Primates with Penile Spines and Sensory Vibrissae

<div><p>Previous studies show that humans have a large genomic deletion downstream of the <i>Androgen Receptor</i> gene that eliminates an ancestral mammalian regulatory enhancer that drives expression in developing penile spines and sensory vibrissae. Here we use a combination of large-scale sequence analysis and PCR amplification to demonstrate that the penile spine/vibrissa enhancer is missing in all humans surveyed and in the Neandertal and Denisovan genomes, but is present in DNA samples of chimpanzees and bonobos, as well as in multiple other great apes and primates that maintain some form of penile integumentary appendage and facial vibrissae. These results further strengthen the association between the presence of the penile spine/vibrissa enhancer and the presence of penile spines and macro- or micro- vibrissae in non-human primates as well as show that loss of the enhancer is both a distinctive and characteristic feature of the human lineage.</p> </div

PCR screen of chimpanzees and bonobos.

<p>A) Alignment of human and chimpanzee genomic sequences. Thick bars indicate existing sequences; narrow lines indicate sequence gaps due to deletions or insertions. Half-arrows indicate the primer pairs used to assay the region. The bracket identifies the chimpanzee DNA previously tested for enhancer activity. The jagged lines indicate a 50 kb break to maintain scale. The primers targeting the chimpanzee enhancer sequence amplify 535 bp that are not expected to be present in the human genome. The primers spanning the deletion breakpoints will amplify 1,674 bp of human sequence, but are separated by over 60 kb in the chimpanzee. B) PCR results of the chimpanzee and bonobo DNA samples. All cases confirm the presence of the conserved enhancer with no evidence of a human-like deletion. </p

Survey of human populations for presence or absence of the <i>AR</i> penile spine/vibrissa enhancer sequences within hCONDEL.569.

<p>A) Number of individuals surveyed (black bars) and total billions of base pairs (Gbp) examined (gray bars) from 14 different human populations. B) No sequences matching the chimpanzee enhancer were found in the worldwide sample of 1,006 individuals, indicating fixed deletion of the AR penile spine/vibrissa enhancer in modern humans. The populations from the Americas are substantially displaced and/or admixed. CEU, Utah residents with ancestry from northern and western Europe; TSI, Toscans in Italy; CHS, Han Chinese South; YRI, Yoruba in Ibadan, Nigeria; LWK, Luhya in Webuye, Kenya; JPT, Japanese in Tokyo, Japan; CHB, Han Chinese in Beijing, China; FIN, Finnish in Finland; GBR, British from England and Scotland; PUR, Puerto Ricans in Puerto Rico; MXL, Mexican Ancestry in Los Angeles, CA, USA; CLM, Colombians in Medellín, Colombia; ASW, African Ancestry in SW USA; IBS, Iberian Populations in Spain.</p

Presence of the <i>AR</i> enhancer in non-human primates.

<p>A) Multiple alignment of the 4,839 bp enhancer in extant non-human primates and mouse. B) PCR confirmation of the presence of the ancestral <i>AR</i> enhancer in gorillas, a gibbon, and orangutans. The ancestral primer pair amplifies predicted products (including a ~450 bp AluY and assembly gap insertion in gibbon) in each of the ape species. The derived (human) primers fail to amplify a corresponding product in any of the apes. C) Phylogeny of the species examined in this study and status of <i>AR</i> enhancer and penile spines. ? Presence/absence of penile spines is not known for the extinct hominids, * Juvenile gorillas likely have penile spines [23,28], † Orangutan specimens have ‘hinged platelets’ that may [22] or may not [23] be homologous to penile spines.</p

Marking out the pitch: a historiography and taxonomy of football fiction

Football, or soccer as it is more commonly referred to in Australia and the US, is arguably the world’s most popular sport. It generates a proportionate volume of related writing. Within this landscape, works of novel-length fiction are seemingly rare. This paper establishes and maps a substantial body of football fiction works, explores elements and qualities exhibited individually and collectively. In bringing together current, limited surveys of the field, it presents the first rigorous definition of football fiction and captures the first historiography of the corpus. Drawing on distant reading methods developed in conjunction with closer textual analyses, the historiography and subsequent taxonomy represent the first articulation of relationships across the body of work, identify growth areas and establish a number of movements and trends. In advancing the understanding of football fiction as a collective body, the paper lays foundations for further research and consideration of the works in generic terms