Biology subjects

Khurshid, M.

Publications and source records attributed to Khurshid, M..

5 recordsLinked to original sources

bioRxiv2025

The study of differential expressions of MCPH and Seckel syndrome genes and their paralogues

Seckel syndrome and MCPH are single-gene neurodevelopmental disorders, with or without dwarfism. These genes are parts of essential cellular pathways but are regulated differently in both forms of microcephaly. These genes have diverged from single ancestral genes in to related but different gene paralogues during evolution. It is suggested that the paralogues might be redundant in other body organs and might rescue any abnormality in cases of MCPH, but not in Seckel syndrome. This study uncovers the spatio-temporal dynamics of these genes together with their paralogues at the mRNA level where the different tissues of embryos might exhibit different transcript variants or different levels of the various transcript variants to find the complementation in case of the MCPH but divergence in case of the Seckel syndrome. Here, we studied Cdk5Rap2-Pde4dip, Phc1-Phc3 (for MCPH) and Cep63-Ccdc67 (for Seckel) in the embryonic mouse tissues using RT-PCR throughout the peak of neurogenesis from E12.5 to E18.5. We found already known and novel spatio-temporal differential expression suggesting different regulation at the mRNA level. The results of PCR were analyzed on the agarose gel and were quantified by assigning relative intensity percentage scores to each band and plotting the cumulative expression of each gene in to the graphs for spatio-temporal dynamics and plotted each gene separately for temporal dynamics. For MCPH, Cdk5Rap2-Pde4dip had similar profiles and seemed to be redundant whereas Phc1-Phc3 seem to have complementary roles in brain development. The expression profiles of Cep63-Ccdc67 were very different indicating of their divergent and essential roles in development.

genetics↗

bioRxiv2023

Benefits of timed matings over blind/random matings in mice to get timed embryos

Mus Musculus has provided scientists a well-adapted animal model for the developmental studies. There is one on one co-relation between molecular determinants such as genes between humans and mice hence making them superior model to study gene expression and to do translation research. Swiss albino mice strain of house mice was used in this study with comparisons of efficiency of pregnancies during two different strategies of mating; i.e., more traditional random/blind mating and more recent timed mating in experimental paradigms to get staged mice embryos. The workflow required for the blind mating was less labor intensive and required minimal maintenance both time and human resource and was easy to execute. On the other hand, timed mating strategy was ideal for getting staged embryos that was efficient in giving pregnancies and was ideal for less equipped labs but however required more maintenance and human resource. The results of comparisons of weight gain with pregnancies was similar in two groups where some un-pregnant mice also showed average or above average weight gain with time. The z-test analysis for difference between two proportions was employed to calculate efficiency of pregnancies in the two groups and p value was found to be 0.06 which suggested that was no significant difference between the two groups however, this might be due to small sample size that was possible in our small setting. The accurate embryonic staging was required in the experiments corresponding to the peak of neurogenesis in mice and embryos were fixed and sectioned and later studied with immunohistochemistry. The timed matings showed to be superior regarding total pregnancies and having accurate stages and is recommended in labs even if in smaller settings and prevent less animal sacrifice.

developmental biology↗

bioRxiv2023

Expression Profile of Primary Microcephaly Genes Cdk5rap2, Cep63 and Their Paralogues Pde4dip, Ccdc67 in Mouse Embryonic and Adult Tissues

Autosomal recessive primary microcephaly (MCPH) is characterized by the prenatal reduction in the human brain growth, without any change in the cerebral architecture. MCPH can result from the bi-allelic mutations in at least thirty genes and still counting on. MCPH genes majorly code for a centrosomal protein subset, cell cycle proteins, nuclear proteins and cytoskeletal proteins. Centrosomal subset is the most highly characterized subset of MCPH proteins. Cep63 and Cdk5rap2 with their paralogues Ccdc67 and Pde4dip play important role for the normal assembly of spindles and in DNA damage response. They regulate neuroepithelial cell division in the developing brain, so decrease in centrosome number results in genomic instability. Study presented in this manuscript was aimed to identify the tissue specific expression of genes with their paralogues (Cep63 and Ccdc67) and (Cdk5rap2 and Pde4dip) in developing and adult normal mice tissue cells. For this purpose we successfully generated timed pregnant mice at the peak of neurogenesis and 36 samples were screened for the expression of these genes and their paralogues. RNA was extracted from the mice tissues using trizol reagent. Extracted RNA was reverse transcribed and cDNA was subjected to PCR amplification using gene specific primers, generated by using primer3 at the intron-exon junction to avoid the genomic interference. One house keeping gene {beta}-actin was used as a positive control. This study reveals that Cep63 and Ccdc67 paralogues are playing a suggestive collective role in the mice development as shown by multiple length bands. Cdk5rap2 an MCPH gene and its paralogue Pde4dip band suggested that maybe they might have redundant roles in body organs apart from the brain. These proteins have tissue-specific expression in all studied tissues from the developing and adult mice. We identified multiple bands in the different samples of all four genes which might reflect towards multiple transcript variants.

developmental biology↗

bioRxiv2021

Interaction of the Causal Agent of Apricot bud gall Acalitus phloeocoptes (Nalepa) with Apricot: Implications in Infested Tissues

Apricot bud gall mite, Acalitus phloeocoptes (Nalepa), is a destructive arthropod pest that causes significant economic losses to apricot trees worldwide. Infested bud examination revealed that the starch granules in the bud axon were extended at the onset of the attack. During the later stages of the attack, the cytoplasm was distributed in apricot. The results also demonstrated that the accumulation of large amounts of cytokinin (zeatin, ZT) and auxin (indoleacetic acid, IAA) led to rapid bud proliferation during the rapid growth period. Abscisic acid (ABA) controls the development of gall buds and plays a vital role in gall bud maturity. The reduction of gibberellic acid (GA3) content led to rapid lignification at the later phase of bud development. Our results reveal the mechanism underlying the interaction of apricot bud gall with its parasite and provide reliable information for designing valuable breeding programs. This study will be quite useful for pest management and will provide a comprehensive evaluation of ecology-based cost-effective control, life history and demographic parameters of A. phloeocoptes.

microbiology↗

bioRxiv2019

Jasmonate-regulated ERF109-MYB51-MYC3 ternary complexes control indolic glucosinolates biosynthesis

Jasmonates (JAs) are plant hormones which regulate biosynthesis of many secondary metabolites, such as glucosinolates (GLSs), through JAs-responsive transcription factors (TFs). The JAs-responsive CYP83B1 gene, has been shown to catalyze the conversion of indole-3-acetaldoxime (IAOx) to indolic glucosinolates (IGLSs). However, little is known about the regulatory mechanism of CYP83B1 gene expression by JAs. In yeast one-hybrid screens using the CYP83B1 promoter as bait we isolated two JAs-responsive TFs ERF109 and MYB51 that are involved in JAs-regulated IGLS biosynthesis. Furthermore, using a yeast two-hybrid assay, we identified ERF109 as an interacting partner of MYB51, and Jasmonate ZIM-domain (JAZ) proteins as interactors of MYB51, and BTB/POZ-MATH (BPM) proteins as interactors of ERF109. Both JAZ and BPM proteins are necessary for the full repression of the ERF109-MYB51-MYC3 ternary complex activity on CYP83B1 gene expression and JA-regulated IGLS biosynthesis. Biochemical analysis showed that the 26S proteasome-mediated degradation of ERF109 protein is mediated by a CRL3BPM E3 ligase independently of JA signaling. Genetic and physiological evidence shows that MYB51 acts as an adaptor and activator to bridge the interaction with the co-activators MYC3 and ERF109, for synergistically activating the CYP83B1 gene expression, and all three factors are essential and exert a coordinated control in JAs-induced IGLS biosynthesis. Overall, this study provides insights into the molecular mechanisms of JAs-responsive ERF109-MYB51-MYC3 ternary complexes in controlling JAs-regulated GLSs biosynthesis, which provides a better understanding of plant secondary metabolism. One-sentence summaryThe JA-responsive ERF109-MYB51-MYC3 ternary complex controls JAs-regulated GLSs biosynthesis.

bioengineering↗