Neurons in the pigeon visual network discriminate between faces, scrambled faces, and sine grating images

Discriminating between object categories (e.g., conspecifics, food, potential predators) is a critical function of the primate and bird visual systems. We examined whether a similar hierarchical organization in the ventral stream that operates for processing faces in monkeys also exists in the avian visual system. We performed electrophysiological recordings from the pigeon Wulst of the thalamofugal pathway, in addition to the entopallium (ENTO) and mesopallium ventrolaterale (MVL) of the tectofugal pathway, while pigeons viewed images of faces, scrambled controls, and sine gratings. A greater proportion of MVL neurons fired to the stimuli, and linear discriminant analysis revealed that the population response of MVL neurons distinguished between the stimuli with greater capacity than ENTO and Wulst neurons. While MVL neurons displayed the greatest response selectivity, in contrast to the primate system no neurons were strongly face-selective and some responded best to the scrambled images. These findings suggest that MVL is primarily involved in processing the local features of images, much like the early visual cortex.

Genome-wide ancestry and introgression in a Zambian baboon hybrid zone

Hybridization in nature offers unique insights into the process of natural selection in incipient species and their hybrids. In order to evaluate the patterns and targets of selection, we examine a recently discovered baboon hybrid zone in the Kafue River valley of Zambia, where Kinda baboons (Papio kindae) and gray-footed chacma baboons (P. ursinus griseipes) coexist with hybridization. We genotyped baboons at 14,962 variable genome-wide autosomal markers using double-digest RADseq. We compare ancestry patterns from this genome-wide dataset to previously reported ancestry from mitochondrial-DNA and Y-chromosome sources. We also fit a Bayesian genomic cline model to scan for genes with extreme patterns of introgression. We show that the Kinda baboon Y chromosome has penetrated the species boundary to a greater extent than either mitochondrial DNA or the autosomal chromosomes. We also find evidence for overall restricted introgression in the JAK/STAT signaling pathway. Echoing results in other species including humans, we find evidence for enhanced and/or directional introgression of immune-related genes or pathways including the toll-like receptor pathway, the blood coagulation pathway, and the LY96 gene. Finally we show enhanced introgression and excess chacma baboon ancestry in the sperm tail gene ODF2. Together, our results elucidate the dynamics of introgressive hybridization in a primate system while highlighting genes and pathways under selection.

The Danish urban system pre-1800: a survey of recent research results

In Denmark, the first actual towns can be dated to the eighth and ninth centuries. The establishment of towns became more significant in the eleventh and twelfth centuries in connection with the state-building process, and these towns were distinctly consumer towns serving as administrative, religious and military centres. From 1200 to 1350 Denmark, similar to the German area, underwent considerable urbanization; a large number of market towns were created, and in contrast to the older ones they were mercantile towns. Denmark thus clearly became the most urbanized country in Scandinavia. As Copenhagen grew in the sixteenth and seventeenth centuries, the urban system decisively changed its character in the direction of a primate system. The characteristics of the primate system are particularly distinct within the boundaries of the Kingdom of Denmark, but less pronounced if the entire monarchy is included in the period in which Denmark was a conglomerate state. The institutional conditions must in general be attributed considerable importance in explaining Danish urban development. Thus, Denmark is one of the countries where town privileges were of great significance until the middle of the nineteenth century.

Characterization of recombinant plasminogen activator production by primate endothelial cells transduced with retroviral vectors

Retroviral vector-mediated expression of plasminogen activators (PAs) from endothelial cells (ECs) has been proposed as a potential therapeutic approach for intravascular thrombosis. To define the potential for gene transfer to increase fibrinolytic activity in a primate system, baboon ECs were transduced with retroviral vectors expressing wild-type and glycosylphosphatidylinositol-anchored urokinase, as well as wild-type and serpin-resistant tissue PA (t-PA). Expression of either t-PA or urokinase was increased by one log over baseline levels. There was no specific effect of either t-PA or urokinase overexpression on endogenous t-PA, urokinase, or PA inhibitor 1 (PAI-1) expression. Recombinant urokinase could be anchored to the cell surface at a level eight-fold above that of receptor-bound urokinase. The majority of secreted urokinase accumulated in conditioned medium as a free proenzyme, whereas both wild-type and serpin-resistant t-PA accumulated almost exclusively in complexes with PAI-1. In most but not all of the assays, the urokinase vectors conferred PA activity above that of the t-PA vectors. These data show that PA synthesis and activity are specifically increased subsequent to retroviral vector-mediated gene transfer in primate ECs. However, definition of an optimal PA vector will require in vivo experimentation.

Characterization of recombinant plasminogen activator production by primate endothelial cells transduced with retroviral vectors

Retroviral vector-mediated expression of plasminogen activators (PAs) from endothelial cells (ECs) has been proposed as a potential therapeutic approach for intravascular thrombosis. To define the potential for gene transfer to increase fibrinolytic activity in a primate system, baboon ECs were transduced with retroviral vectors expressing wild-type and glycosylphosphatidylinositol-anchored urokinase, as well as wild-type and serpin-resistant tissue PA (t-PA). Expression of either t-PA or urokinase was increased by one log over baseline levels. There was no specific effect of either t-PA or urokinase overexpression on endogenous t-PA, urokinase, or PA inhibitor 1 (PAI-1) expression. Recombinant urokinase could be anchored to the cell surface at a level eight-fold above that of receptor-bound urokinase. The majority of secreted urokinase accumulated in conditioned medium as a free proenzyme, whereas both wild-type and serpin-resistant t-PA accumulated almost exclusively in complexes with PAI-1. In most but not all of the assays, the urokinase vectors conferred PA activity above that of the t-PA vectors. These data show that PA synthesis and activity are specifically increased subsequent to retroviral vector-mediated gene transfer in primate ECs. However, definition of an optimal PA vector will require in vivo experimentation.

Structure of rhesus monkey relaxin predicted by analysis of the single-copy rhesus monkey relaxin gene

ABSTRACT The gene encoding rhesus monkey relaxin has been investigated. A cDNA library was prepared using corpus luteal RNA from a pregnant rhesus monkey, cDNA clones encoding relaxin were isolated and the nucleotide sequence was determined. The amino acid sequence of rhesus monkey preprorelaxin, predicted from the cDNA, demonstrates that the sequence has not been strongly conserved when compared with that of man, although features characteristic of the relaxin molecule have been maintained. This structural information will allow production of rhesus monkey relaxin, leading to studies investigating the bioactivity of relaxin in a homologous primate system. Southern blot analysis indicated that there is only one relaxin gene in the rhesus monkey and baboon genomes. In this respect these primate genomes are different from the human genome which contains two relaxin genes.