CDK6 associates with the centrosome during mitosis and is mutated in a large Pakistani family with primary microcephaly.

Autosomal recessive primary microcephaly (MCPH) is characterized by reduced head circumference, reduction in the size of the cerebral cortex with otherwise grossly normal brain structure and variable intellectual disability. MCPH is caused by mutations of 11 different genes which code for proteins implicated in cell division and cell cycle regulation. We studied a consanguineous eight-generation family from Pakistan with ten microcephalic children using homozygosity mapping and found a new MCPH locus at HSA 7q21.11-q21.3. Sanger sequencing of the most relevant candidate genes in this region revealed a homozygous single nucleotide substitution c.589G>A in CDK6, which encodes cyclin-dependent kinase 6. The mutation changes a highly conserved alanine at position 197 into threonine (p.Ala197Thr). Post hoc whole-exome sequencing corroborated this mutation's identification as the causal variant. CDK6 is an important protein for the control of the cell cycle and differentiation of various cell types. We show here for the first time that CDK6 associates with the centrosome during mitosis; however, this was not observed in patient fibroblasts. Moreover, the mutant primary fibroblasts exhibited supernumerary centrosomes, disorganized microtubules and mitotic spindles, an increased centrosome nucleus distance, reduced cell proliferation and impaired cell motility and polarity. Upon ectopic expression of the mutant protein and knockdown of CDK6 through shRNA, we noted similar effects. We propose that the identified CDK6 mutation leads to reduced cell proliferation and impairs the correct functioning of the centrosome in microtubule organization and its positioning near the nucleus which are key determinants during neurogenesis.

Impact of different decontamination methods on the reduction of spiromesifen residue in chilli fruits.

Chilli is an indispensable food item in the daily life of humans but it is affected by many insects, so various pesticides, including spiromesifen, are applied to chilli crops to protect this crop from insect infestation. However, the use of pesticides poses environmental and health issues. These issues have raised the demand for pesticide-free chillies among consumers. The primary aim of this study was to assess the efficacy of various decontamination methods in removing spiromesifen residues from chilli fruits. A randomized block design was employed to conduct a supervised field experiment at the Rajasthan Agricultural Research Institute in Durgapura, Jaipur, India. The samples of chillies treated with pesticides are subjected to seven different homemade techniques. The samples were extracted using the QuEChERS method, known for its efficiency, affordability, simplicity, robustness, and safety. The analysis of spiromesifen residues was conducted using gas chromatography (GC) equipped with an electron capture detector (ECD), and the results were verified using gas chromatography-mass spectrometry (GC-MS). Out of several decontamination methods, the lukewarm water treatment was more effective than any other decontamination method, which led to the highest elimination of spiromesifen residue, whereas rinsing with tap water eliminates the least amount of spiromesifen residue. So, the lukewarm water treatment is a safe, cost-effective, and eco-friendly approach to remove spiromesifen residues from Chilli.

Identification of a null allele in genetic tests for bovine leukocyte adhesion deficiency in Pakistani Bos indicus × Bos taurus cattle.

Two clinically healthy mature Pakistani Bos indicus × Bos taurus cattle were genotyped as homozygous affected for the lethal immunodeficiency disorder bovine leukocyte adhesion deficiency (BLAD) using previously described PCR-RFLP based DNA tests which was confirmed by sequencing. Sequencing of Bos taurus and B. indicus × B. taurus genomic DNA surrounding the disease causing mutation (c.383A > G) in the ITGB2 gene identified numerous variations in exonic and intronic regions within and between species, including substantial variation in primer annealing sites for three PCR-RFLP tests for one of the B. indicus allelic variants. These variations in the primer annealing sites resulted in a null allele in the DNA tests causing the misdiagnosis of some heterozygous B. taurus × B. indicus cattle to be classified as homozygous affected. New primers were designed and a modified test was developed which simultaneously identified the disease mutation and the Pakistani B. indicus allelic variant associated with the null allele in the previous test.