Are kea prosocial?

Prosocial behaviour is widespread in humans, but evidence for its occurrence in other species is mixed. We presented a parrot species, the kea (Nestor notabilis) with a series of experiments to test whether they exhibit prosocial tendencies. Across the first round of testing, in our first condition, two of the four kea acted prosocially, as they preferred to choose a prosocial token which rewarded both themselves and a partner, rather than a token that rewarded only themselves. Three of the four kea then showed a preference for the prosocial token in a second condition where they alternated taking turns with a partner. However, no kea showed a decrease in the third yoked control condition in which the experimenter replicated the token choice made by the partner in the previous alternating trials. This yoked condition was used to dissociate truly reciprocal behaviour, whereby the actor made choices based on their partner's choices, from a response to the amount of rewards conferred to the partner. Finally, three of the four kea continued to choose the prosocial token in the fourth asocial control condition where no partner was present. However, in round two of testing, one kea changed its token choices to a similar pattern to that expected if kea are prosocial, in that it preferred the prosocial token in the initial condition, showed a trend for the prosocial token when turns were alternated, but chose at chance in the yoked and asocial conditions. This study therefore found no evidence of spontaneous reciprocity in kea but further testing is required before we can conclude that kea are not capable of prosocial behaviour at all.     

Are Megabats Big?

Traditionally, bats (Order Chiroptera) are divided into two suborders, Megachiroptera (“megabats”) and Microchiroptera, and this nomenclature suggests a consistent difference in body size. To test whether megabats are, in fact, significantly larger than other bats, we compared them with respect to average body mass (log transformed), using both conventional and phylogenetic statistics. Because bat phylogeny is controversial, including the position of megabats, we employed several analyses. First, we derived two generic-level topologies for 101 genera, one with megabats as the sister of all other bats (“morphological” tree), the other with megabats as the sister of one specific group of microbats, the Rhinolophoidea (“molecular” tree). Second, we used a recently published “supertree” that allowed us to analyze body mass data for 656 species. In addition, because the way body mass has evolved is generally unknown, we employed several sets of arbitrary branch lengths on both topologies, as well as transformations of the branches intended to mimic particular models of character evolution. Irrespective of the topology or branch lengths used, log body mass showed highly significant phylogenetic signal for both generic and species-level analyses (all P≤ 0.001). Conventional statistics indicated that megabats were indeed larger than other bats (P ? 0.001). Phylogenetic analyses supported this difference only when performed with certain branch lengths, thus demonstrating that careful consideration of the branch lengths used in a comparative analysis can enhance statistical power. A conventional Levene's test indicated that log body mass was more variable in megabats as compared with other bats (P=0.075 for generic-level data set, P ? 0.001 for species-level). A phylogenetic equivalent, which gauges the amount of morphospace occupied (or average minimum rate of evolution) relative to topology and branch lengths specified, indicated no significant difference for the generic analyses, but did indicate a difference for some of the species-level analyses. The ancestral bat is estimated to have been approximately 20–23 g in body mass (95% confidence interval approximately 9–51 g).     

Are alpha-gliadins glycosylated?

Alpha-gliadins isolated by carboxymethylcellulose chromatography contain noncovalently bound glucose probably due to contaminating proteoglycans and to material shed from the column. Traces of carbohydrate remain strongly bound to alpha-gliadins even after harsh denaturation, but our results indicate alpha-gliadins are not glycoproteins. Suggestions that gliadins are glycoproteins are probably due to contamination with this glucose and the presence of these proteoglycans.     

Are PARPs promiscuous?

Post-translational modifications exist in different varieties to regulate diverse characteristics of their substrates, ultimately leading to maintenance of cell health. The enzymes of the intracellular poly(ADP-ribose) polymerase (PARP) family can transfer either a single ADP-ribose to targets, in a reaction called mono(ADP-ribosyl)ation or MARylation, or multiple to form chains of poly(ADP-ribose) or PAR. Traditionally thought to be attached to arginine or glutamate, recent data have added serine, tyrosine, histidine and others to the list of potential ADP-ribose acceptor amino acids. PARylation by PARP1 has been relatively well studied, whereas less is known about the other family members such as PARP7 and PARP10. ADP-ribosylation on arginine and serine is reversed by ARH1 and ARH3 respectively, whereas macrodomain-containing MACROD1, MACROD2 and TARG1 reverse modification of acidic residues. For the other amino acids, no hydrolases have been identified to date. For many PARPs, it is not clear yet what their endogenous targets are. Better understanding of their biochemical reactions is required to be able to determine their biological functions in future studies. In this review, we discuss the current knowledge of PARP specificity in vitro and in cells, as well as provide an outlook for future research.     

Are metacaspases caspases?

The identification of caspases as major regulators of apoptotic cell death in animals initiated a quest for homologous peptidases in other kingdoms. With the discovery of metacaspases in plants, fungi, and protozoa, this search had apparently reached its goal. However, there is compelling evidence that metacaspases lack caspase activity and that they are not responsible for the caspaselike activities detected during plant and fungal cell death. In this paper, we attempt to broaden the discussion of these peptidases to biological functions beyond apoptosis and cell death. We further suggest that metacaspases and paracaspases, although sharing structural and mechanistic features with the metazoan caspases, form a distinct family of clan CD cysteine peptidases.     

Are protochordates chordates?

This paper challenges the widely accepted view that protochordates (lancelets and tunicates) should be included together with vertebrates within the monophyletic assemblage of the chordates since they share a few distinguishing characters, such as a dorsally located notochord and central nervous system (CNS). The homology of these axial structures is not supported convincingly by morphology and molecular biology. Besides, for notochord and CNS to be dorsal, the embryos of protochordates, unlike those of vertebrates, should be orientated with the blastopore coincident with the dorsal side. This embryonic orientation is never reported in other bilaterians and is inconsistent with the genetic control of the body axes. Alternatively, protochordates could be orientated just as the vertebrates according to the regulation of axial patterning. In this case, the notochord and CNS appear to be located on the ventral side. As suggested by molecular and structural data, they may correspond to the stomodaeal/ventral midline cells and CNS of gastroneuralians. This conclusion may have far-reaching implications concerning the origin of the vertebrates and the evolution of nervous systems and neural crest/placodes.  © 2006 The Linnean Society of London, Biological Journal of the Linnean Society , 2006, 87 , 261–284.