Wolf-Hirschhorn syndrome: A review and update
AMERICAN JOURNAL OF MEDICAL GENETICS PART C-SEMINARS IN MEDICAL GENETICS
Authors: Battaglia, Agatino; Carey, John C.; South, Sarah T.
Abstract
Since 4p- was first described in 1961, significant progress has been made in our understanding of this classic deletion disorder. We have been able to establish a more complete picture of the WHS phenotype associated with distal 4p monosomy, and we are working to delineate the phenotypic effects when each gene on distal 4p is hemizygous. Our aim is to provide genotype-specific anticipatory guidance and recommendations to families of individuals with a diagnosis of WHS. In addition, establishing the molecular underpinnings of the disorder will potentially suggest targets for molecular treatments. Thus, the next step is to determine the precise effects of specific gene deletions. As we look forward to deepening our understanding of distal 4p deletion, our focus will continue to be on the establishment of robust genotype-phenotype correlations and the penetrance of these phenotypes. We will continue to follow our WHS cohort closely as they age to determine the presence or absence of some of these comorbidities, including hepatic neoplasms, hematopoietic dysfunction, and recurrence of seizures. We will also continue to refine the critical regions for other phenotypes as we enroll additional (hopefully informative) participants into the research study and as the mechanisms of the genes in these regions are elucidated. New animal models will also be developed to further our understanding of the effects of hemizygosity as well as to serve as models for treatment development. (c) 2015 Wiley Periodicals, Inc.
The mitochondrial membrane protein FgLetm1 regulates mitochondrial integrity, production of endogenous reactive oxygen species and mycotoxin biosynthesis in Fusarium graminearum
MOLECULAR PLANT PATHOLOGY
Authors: Tang, Guangfei; Zhang, Chengqi; Ju, Zhenzhen; Zheng, Shiyu; Wen, Ziyue; Xu, Sunde; Chen, Yun; Ma, Zhonghua
Abstract
Deoxynivalenol (DON) is a mycotoxin produced in cereal crops infected with Fusarium graminearum. DON poses a serious threat to human and animal health, and is a critical virulence factor. Various environmental factors, including reactive oxygen species (ROS), have been shown to interfere with DON biosynthesis in this pathogen. The regulatory mechanisms of how ROS trigger DON production have been investigated extensively in F. graminearum. However, the role of the endogenous ROS-generating system in DON biosynthesis is largely unknown. In this study, we genetically analysed the function of leucine zipper-EF-hand-containing transmembrane 1 (LETM1) superfamily proteins and evaluated the role of the mitochondrial-produced ROS in DON biosynthesis. Our results show that there are two Letm1 orthologues, FgLetm1 and FgLetm2, in F. graminearum. FgLetm1 is localized to the mitochondria and is essential for mitochondrial integrity, whereas FgLetm2 plays a minor role in the maintenance of mitochondrial integrity. The FgLetm1 mutant demonstrated a vegetative growth defect, abnormal conidia and increased sensitivity to various stress agents. More importantly, the FgLetm1 mutant showed significantly reduced levels of endogenous ROS, decreased DON biosynthesis and attenuated virulence in planta. To our knowledge, this is the first report showing that mitochondrial integrity and endogenous ROS production by mitochondria are important for DON production and virulence in Fusarium species.