Biology of a new species of socially parasitic thrips (Thysanoptera: Phlaeothripidae) inside Dunatothrips nests,with evolutionary implications for inquilinism in thrips

Akainothrips francisi sp. nov. is shown to be an inquiline (i.e. it invades, and breeds within, domiciles of another species). Currently, its only known host is Dunatothrips aneurae, a subsocial thrips that creates silken domiciles by securing together phyllodes of mulga (Acacia aneura) in the arid zone of Australia. We found Ak. francisi prolifically breeding inside live D. aneurae host domiciles, both immature and mature. Akainothrips francisi did not kill its host and we saw no evidence of antagonistic host‐inquiline interactions. This is thus the second demonstrably inquiline species of Acacia thrips, although other possible inquilines have been suggested including two Akainothrips. We found that Ak. francisi occurred with positive density dependence, and was associated with moderately reduced host reproduction. This latter association was especially evident in larger host domiciles, suggesting that Ak. francisi either inhibits further host reproduction after invasion or exploits poor quality hosts more successfully. Sex ratios were slightly female biased. Akainothrips francisi males were exceptionally variable in size, colour, and foreleg size compared to females, with morphs co‐occurring within domiciles, suggesting sexual selection and the possibility of different male reproductive strategies. The discovery of Ak. francisi highlights particular morphological affinities among known or suspected inquiline Acacia thrips within Akainothrips and other genera, allowing us to hypothesize a common origin of this lifestyle from within Akainothrips. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, ?? , ??–??.     

Computational Studies of Ligand-Receptor Interactions in Bitter Taste Receptors

Phenylthiocarbamide tastes intensely bitter to some individuals, but others find it completely tasteless. Recently, it was suggested that phenylthiocarbamide elicits bitter taste by interacting with a human G protein-coupled receptor (hTAS2R38) encoded by the PTC gene. The phenylthiocarbamide nontaster trait was linked to three single nucleotide polymorphisms occurring in the PTC gene. Using the crystal structure of bovine rhodopsin as template, we generated the 3D structure of hTAS2R38 bitter taste receptor. We were able to map on the receptor structure the amino acids affected by the genetic polymorphisms and to propose molecular functions for two of them that explained the emergence of the nontaster trait. We used molecular docking simulations to find that phenylthiocarbamide exhibited a higher affinity for the target receptor than the structurally similar molecule 6-n-propylthiouracil, in line with recent experimental studies. A 3D model was constructed for the hTAS2R16 bitter taste receptor as well, by applying the same protocol. We found that the recently published experimental ligand binding affinity data for this receptor correlated well with the binding scores obtained from our molecular docking calculations.     

Characterization of eight microsatellite loci in Grant's gazelle (Gazella granti)

Eight microsatellite loci were isolated from a genomic DNA library created from Grant's gazelle (Gazella granti). Observed and expected levels of heterozygosity were computed utilizing 20 individuals from a population in Central Kenya. Tests for Hardy–Weinberg equilibria were conducted and found that two of the eight loci deviated from equilibrium in this population. These markers were developed to analyse the genetic effects of culling and isolation on a game preserve in Kenya.     

Phylogenetic position of a remarkable new fideliine bee from northern Chile (Hymenoptera: Megachilidae)

Fideliine bees are an archaic group with a disjunct distribution mostly restricted to deserts of South America and South Africa. This group was previously thought to be more diverse in Africa than in South America, where only one genus (Neofidelia) comprising five species is known. Here we describe a species belonging to a second South American genus: Xenofidelia colorada Packer gen. et sp.n. , from northern Chile. The species is illustrated and its phylogenetic position within Megachilidae is assessed using morphological, molecular and combined data. The 214 character morphological matrix includes 55 new characters with an additional 16 hitherto unexplored for megachilid phylogeny. The molecular dataset is based upon seven nuclear gene sequences, totalling 6439 bp, many of which are published for the first time for particular megachilid taxa. In all analyses, Xenofidelia was found as sister to Neofidelia (endemic to Chile and Peru). It differs from that genus most notably in its short mouthparts, absence of a glossal rod, unmodified female metabasitarsus and an elongate and horizontal dorsal surface of the metapostnotum. Morphological and combined data support a monophyletic Fideliinae (excluding Pararhophites), while molecular data alone failed to recover fideliine monophyly. Dating analyses suggest that Xenofidelia and Neofidelia diverged 34.3–40.6 Ma, indicating that New World fideliines were probably present in arid habitats of South America during the Eocene. This divergence time predates both the main orogenic events that resulted in the formation of the Andean mountains and the origin of hyperarid conditions in the Atacama Desert; it also corresponds to a period prior to the origin of the summer rainfall area in the far north of Chile where the new genus is found. These results support the view that arid habitats have been present continuously in South America since the Eocene. This published work has been registered in ZooBank, http://zoobank.org/urn:lsid:zoobank.org:pub:EA69BB4A‐6F59‐4A15‐AB44‐2A8949E3CF8F .