Exploring a Non-model Teleost Genome Through RAD Sequencing - Linkage Mapping in Common Pandora, Pagellus erythrinus and Comparative Genomic Analysis

Common pandora (Pagellus erythrinus) is a benthopelagic marine fish belonging to the teleost family Sparidae, and a newly recruited species in Mediterranean aquaculture. The paucity of genetic information relating to sparids, despite their growing economic value for aquaculture, provides the impetus for exploring the genomics of this fish group. Genomic tool development, such as genetic linkage maps provision, lays the groundwork for linking genotype to phenotype, allowing fine-mapping of loci responsible for beneficial traits. In this study, we applied ddRAD methodology to identify polymorphic markers in a full-sib family of common pandora. Employing the Illumina MiSeq platform, we sampled and sequenced a size-selected genomic fraction of 99 individuals, which led to the identification of 920 polymorphic loci. Downstream mapping analysis resulted in the construction of 24 robust linkage groups, corresponding to the karyotype of the species. The common pandora linkage map showed varying degrees of conserved synteny with four other teleost genomes, namely the European seabass (Dicentrarchus labrax), Nile tilapia (Oreochromis niloticus), stickleback (Gasterosteus aculeatus), and medaka (Oryzias latipes), suggesting a conserved genomic evolution in Sparidae. Our work exploits the possibilities of genotyping by sequencing to gain novel insights into genome structure and evolution. Such information will boost the study of cultured species and will set the foundation for a deeper understanding of the complex evolutionary history of teleosts

Free availability of high-energy foods led to energy over-ingestion and protein under-ingestion in choice-fed broilers

The objective of this study was to compare energy and protein content of the diet selected by choice-fed broilers with thatof broilers fed a balanced diet. One hundred and eighty 1-day-old male broilers were randomly assigned in groups of 10to one of three experimental treatments (n = 6). Control broilers were fed a standard balanced diet, whereas choice-fedbroilers were fed three foods which were more concentrated (Choice C+ treatment) or less concentrated (Choice C?treatment) in protein, carbohydrate or fat. We evaluated food intake behavior, nutrient intake, and performance param-eters of broilers from 2 to 7 weeks of age. Choice C+ broilers showed enhanced preference for the high-fat food, whichled to higher energy intake and lower protein intake than those of control broilers at 2 to 4 weeks of age. Body weight,weight gain and feed conversion efficiency were negatively affected by diet selection of Choice C+ broilers. Choice C?broilers selected a balanced diet, and showed performance parameters similar to those of control broilers. Our results supported the hypothesis that free availability of high-energy foods bias ingestive behavior of choice-fed broilers toward selecting a diet with higher energy and lower protein than needed for normal growth.Fil: Catanese, Francisco Hernan. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida(i); Argentina. Universidad Nacional del Sur. Departamento de Agronomía; ArgentinaFil: Rodríguez Ganduglia, Héctor. Universidad Nacional del Sur. Departamento de Agronomía; ArgentinaFil: Villalba, Juan Jose. State University Of Utah; Estados UnidosFil: Distel, Roberto Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida(i); Argentina. Universidad Nacional del Sur. Departamento de Agronomía; Argentin

Behavior of kestrels feeding on frugivorous lizards: implications for secondary seed dispersal

Secondary seed dispersal is a multistep system that includes 2 or more dispersal processes that can increase the distance from which seeds arrive. This phenomenon is relatively common in some habitats of subtropical oceanic islands due to the frequent frugivore--predator interactions found in them. In this study, we describe how the Eurasian Kestrel is an effective disperser of plants in the secondary seed dispersal process, through interaction with frugivorous lizards. Experiments using captive wild kestrels, along with field data, showed that predation of kestrels on lizards leads to a secondary seed dispersal with 2 possible outcomes: 1) most seeds (89%) are not consumed by kestrels because they reject the lizards' digestive tracts and so receive only the gut treatment of lizards and 2) a small fraction of seeds (11%) appeared inside the kestrel pellets as a result of indirect ingestion by this raptor, thus undergoing double gut treatment. So, 2 different seed dispersal distances may result from this interaction: 1) when the kestrels capture the lizard and transport it to a perch where the seed-containing guts are discarded and 2) when they indirectly ingest a few seeds from lizards, consequently increasing the dispersal distance. Seeds from the Macaronesian plant species Rubia fruticosa were tested, finding that those passed through kestrels had a lower germinability than those that remained inside the rejected lizards' digestive tracts, which had similar germination rates to those from control plants (uningested seeds). The kestrel can be considered an important and effective long-distance seed disperser due to the high abundance of frugivorous lizards in their diet, their stereotyped consumption behavior, and the effectiveness of their seed dispersal. Copyright 2009, Oxford University Press.