Rare structural variants disrupt multiple genes in neurodevelopmental pathways in schizophrenia

Schizophrenia is a devastating neurodevelopmental disorder whose genetic influences remain elusive. We hypothesize that individually rare structural variants contribute to the illness. Microdeletions and microduplications >100 kilobases were identified by microarray comparative genomic hybridization of genomic DNA from 150 individuals with schizophrenia and 268 ancestry-matched controls. All variants were validated by high-resolution platforms. Novel deletions and duplications of genes were present in 5% of controls versus 15% of cases and 20% of young-onset cases, both highly significant differences. The association was independently replicated in patients with childhood-onset schizophrenia as compared with their parents. Mutations in cases disrupted genes disproportionately from signaling networks controlling neurodevelopment, including neuregulin and glutamate pathways. These results suggest that multiple, individually rare mutations altering genes in neurodevelopmental pathways contribute to schizophrenia.     

Effect of nitrogen fertilization on the nutritional quality of wheat variety,Yecora Rojo

The effects of N-fertilization on the nutritional quality of short-straw wheat variety, Yecora Rojo, was studied under sprinkler irrigation system. The fertilizers applied were the conventional N-fertilizer, urea (U) applied as single dose or in three split applications (U-S), and the slow release N-fertilizers, ureaform (UF) (38% N and 20 N), osmocote (OC) with 9 or 14 months longevity and sulphur-coated urea (SCU) with either 17% or 37% dissolution rates in 7 days. These fertilizers were applied at 0 (control), 75, 125, and 175 kg/ha during the 1982–1983 season. Results indicated that at 75 kg/ha there was no significant change in the protein content. At 125 kg/ha, the protein content increased (P<0.05) with urea (applied in three split applications) and OC. At 175 kg/ha, all the fertilizers increased the protein content with the exception of urea (applied as single dose) and UF. Ash content tended to decrease with increasing levels of N, while fat and crude fiber were unaffected. All the fertilizers increased the protein yield (kg/ha), the maximum increase occurring with the slow-release N fertilizers, OC and SCU. Except UF, all the fertilizers decreased the lysine content significantly (P<0.05) in the protein moeity at 175 kg/ha level but lysine percentage in the grain was not reduced. The yield (kg/ha) of individual amino acids including lysine was increased several times at the 175 kg/ha level. P content tended to decrease while Fe and Zn increased with fertilization. Slow-release N-fertilizers, OC and SCU as well as urea (in 3 split applications) appear to have a significant positive effect on the nutritional quality of the grains of wheat variety, Yecora Rojo.     

A whole genome scan to map QTL for milk production traits and somatic cell score in Canadian Holstein bulls

The detection and mapping of genetic markers linked to quantitative trait loci (QTL) can be utilized to enhance genetic improvement of livestock populations. With the completion of the bovine genome sequence assembly, single nucleotide polymorphisms (SNP) assays spanning the whole bovine genome and research work on large scale identification, validation and analysis of genotypic variation in cattle has become possible. The objective of the present study was to perform a whole genome scan to identify and map QTL affecting milk production traits and somatic cell scores using linkage disequilibrium (LD) regression and 1536 SNP markers. Three and 18 SNP were found to be associated with only milk yield (MY) at a genome and chromosome wise significance (p < 0.05) level respectively. Among the 21 significant SNP, 16 were in a region reported to have QTL for MY in other dairy cattle populations and while the rest five were new QTL finding. Four SNP out of 21 are significant for the milk production traits (MY, fat yield, protein yield (PY), and milk contents) in the present study. Six and nine SNP were associated with PY at a genome and chromosome wise significant (p < 0.05) level respectively. Three and 17 SNP were found to be associated with FY at a genome and chromosome wise significant (p < 0.05) level. Five and seven SNP were mapped with somatic cell score at a genome and chromosome wise significant (p < 0.05) level respectively. The results of this study have revealed QTL for MY, PY, protein percentage, FY, fat percentage, somatic cell score and persistency of milk in the Canadian dairy cattle population. The chromosome regions identified in this study should be further investigated to potentially identify the causative mutations underlying the QTL.     

Controlled-environment and field evaluation of heat stress induced genetic variability on translocation efficiency and grain filling traits in rice

Journal of Crop Science and Biotechnology - The grain filling of rice is gets weakened by heat stress due to reduced spike photosynthesis at high temperature stress. An alternate source of carbon...