Genome evolution in the allotetraploid frog Xenopus laevis

To explore the origins and consequences of tetraploidy in the African clawed frog, we sequenced the Xenopus laevis genome and compared it to the related diploid X. tropicalis genome. We characterize the allotetraploid origin of X. laevis by partitioning its genome into two homoeologous subgenomes, marked by distinct families of ???fossil??? transposable elements. On the basis of the activity of these elements and the age of hundreds of unitary pseudogenes, we estimate that the two diploid progenitor species diverged around 34 million years ago (Ma) and combined to form an allotetraploid around 17-18 Ma. More than 56% of all genes were retained in two homoeologous copies. Protein function, gene expression, and the amount of conserved flanking sequence all correlate with retention rates. The subgenomes have evolved asymmetrically, with one chromosome set more often preserving the ancestral state and the other experiencing more gene loss, deletion, rearrangement, and reduced gene expression.ope

Survey the Relation between Rice Consumption with Aflatoxin M1 Excretion Rate in Yazd Women of using Biomarkers

Introduction: Aflatoxins are usually produced from Aspergillus Flavus and Aspergillus Parasiticus. This toxin is found in the most of foods, such as rice. The aim of this study was to survey the relation between rice consumption with Aflatoxin M1 excretion rate in women of Yazd using biomarkers. Methods: This was a cross sectional-descriptive study that was done in 2014. Eighty five women were selected among women who referred to health centers of Yazd. ELISA method was used to measure Aflatoxin M1 in urine samples. Results: The results show that from total number of 85 women, 94% were excreted Aflatoxin M1. There was a significant difference between rice consumption (p=0.015) and type of consumed rice (p= 0.023) with excretion of Aflatoxin M1. Conclusion: According to the results it can be concluded that with increasing rice consumption, daily intake of Aflatoxin increases. Therefore the amount of Aflatoxin in rice consumption by women of Yazd is high and a lot of people are exposed to high concentration of Aflatoxin and health hazards related to it