The Drosophila melanogaster Genetic Reference Panel

A major challenge of biology is understanding the relationship between molecular genetic variation and variation in quantitative traits, including fitness. This relationship determines our ability to predict phenotypes from genotypes and to understand how evolutionary forces shape variation within and between species. Previous efforts to dissect the genotype-phenotype map were based on incomplete genotypic information. Here, we describe the Drosophila melanogaster Genetic Reference Panel (DGRP), a community resource for analysis of population genomics and quantitative traits. The DGRP consists of fully sequenced inbred lines derived from a natural population. Population genomic analyses reveal reduced polymorphism in centromeric autosomal regions and the X chromosome, evidence for positive and negative selection, and rapid evolution of the X chromosome. Many variants in novel genes, most at low frequency, are associated with quantitative traits and explain a large fraction of the phenotypic variance. The DGRP facilitates genotype-phenotype mapping using the power of Drosophila genetics

Spin hall effect associated with SU(2) gauge field

In this paper, we focus on the connection between spin Hall effect and spin force. Here we investigate that the spin force due to spin-orbit coupling, which in two-dimensional system is equivalent to forces of Hirsch and Chudnovsky besides constant factors 3 and 3/2 respectively, is a part of classic Anandan force, and that the spin Hall effect is an anomalous Hall effect. Furthermore, we develop the method of AC phase to derive the formula for the spin force, and find that the most basic spin Hall effect originates from the AC phase and is therefore an intrinsic quantum mechanical property of spin. This method differs from approach of Berry phase in the study of anomalous Hall effect, which is the intrinsic property of the perfect crystal. On the other hand, we use an elegant skill to show that the Chudnovsky-Drude model is reasonable, and further have improved the theoretical values of spin Hall conductivity of Chudnovsky. Compared to the theoretical values of spin Hall conductivity in the Chudnovsky-Drude model, ours are in better agreement with experimentation. Finally, we discuss the relation between spin Hall effect and fractional statistics.Comment: 16 pages, 5 figures, 1 tabl

Peso à cobrição e ganho de peso durante a gestação de cabras nativas, exóticas e mestiças no semi-árido Mating weight and weight gain during gestation of native, exotic and crossbred goats in the semi-arid

Avaliaram-se os efeitos de mês, ano, ordem de parto e tipo de parto sobre o peso à cobrição (PC) e o ganho de peso durante a gestação (GP), respectivamente, de 753 e 527 cabras nativas Canindés, 463 e 333 cabras exóticas Anglo-nubianas, 374 e 296 Alpinas, 151 e 87 de mestiças ½ Alpina (A) ½ Sem Raça Definida (SRD), 92 e 73 ¾ Alpina (A) ¼ SRD, criadas na Estação Experimental de Pendência - EMEPA-PB, Soledade-PB, na microrregião semi-árida da Paraíba, em regime semi-intensivo, no período de 1980 a 1994. O mês foi significativo sobre os pesos à cobrição das matrizes Canindés, Anglo-nubianas, ½ A ½ SRD e ¾ A ¼ SRD. O ano influenciou o PC de todos os grupos genéticos. O efeito do ano sobre o GP foi significativo para as cabras Canindés, Anglo-nubianas, ½ A ½ SRD e Alpinas. O peso à cobrição elevou-se com o aumento da ordem de parto e o GP foi mais evidente entre as cabras de primeiro parto. O tipo de parto foi significativo sobre o GP das matrizes nubianas, ¾ A ¼ SRD e Alpina, que tiveram maiores ganhos quando pariram apenas um cabrito. A raça influenciou o PC e o GP de todas as matrizes. A raça nativa foi a mais leve e com o melhor ganho de peso; as exóticas, as mais pesadas e com GP inferiores aos da raça Canindé e da mestiça ½ A ½ SRD; e a mestiça ¾ A ¼ SRD, a raça com peso corporal (PC) e GP semelhantes às exóticas. Concluiu-se que a composição genética dos animais e os fatores ambientais, como mês, ano, ordem e tipo de parto, refletiram sobre o peso à cobrição e o ganho de peso durante a gestação das matrizes estudadas.<br>The effects of month, year, order and type parturition on mating weight (MW), weight gain during gestation (WG), respectively, of 753 and 527 Caninde native goats, 463 and 333 exotic Anglo Nubian and 374 and 296 Alpine goats, 151 and 87 crossbred ½ Alpine ½ SRD, and 92 and 73 ¾Alpine ¼SRD goats, raised in the Experimental Station of the Governmental Research Institute (EMEPA-PB), Soledade - Paraiba - Brazil, in the period from 1980 to 1994. The effect of month was significant on MW of the Caninde, Anglo Nubian and crossbred goats. The year influenced MW of all genetic groups and effect on WG was significant for Caninde, Anglo Nubian, ½A ½SRD and Alpine goats. Mating weight increased as parturition order increased and WG was evident in the goats of first kidding. Type parturition showed significant effect on WG of Nubian, ¾ A ¼ SRD and Alpine goats, that showed higher WG when had single kidding. Significant difference among genetic groups was observed for MW and WG. The native goats were more weightless than the exotic and crossbred goats, however showed better weight gain during gestation. There was superiority of mating weights of exotic than the native and crossbred goats. The animal genetic composition and environmental factors, as month, year, order and type of birth, affected mating weight and weight gain during the gestation of the studied flock