Biology subjects

Zia, S.

Publications and source records attributed to Zia, S..

7 recordsLinked to original sources

bioRxiv2024

Mathematical modeling using box-behnken response surface design for optimal DNA yield with variable parameters of time, temperature, and proteinase K concentration

The current research aims to explore an enzyme-assisted inorganic DNA extraction protocol to obtain maximum yield from whole blood. We considered various operating conditions such as incubation temperature and time along with proteinase K enzyme concentration. To model and simulate the extraction process, Box-Behnken Design (BBD) was employed with three factors and its five levels, coupled with the desired functional response surface methodology (RSM). RSM entails fitting a mathematical model for experimental data to optimize a response variable with Box-Behnken Design. The best simulation settings yielded the maximum DNA at an incubation temperature of 56{degrees}C for 10 hours and proteinase K enzyme concentration of 10{micro}L. Utilizing these parameters, a yield of 300{micro}L was obtained. Furthermore, other DNA extraction parameters may also be added for a more robust design for obtaining the maximum DNA yield.

molecular biology↗

bioRxiv2024

Senescent-like microglia limit remyelination through the senescence associated secretory phenotype

The capacity to regenerate myelin in the central nervous system (CNS) diminishes with age. This decline is particularly evident in multiple sclerosis (MS), which has been suggested to exhibit features of accelerated biological aging. Whether cellular senescence, a hallmark of aging, contributes to remyelination impairment remains unknown. Here, we show that senescent cells (SCs) accumulate within demyelinated lesions after injury, and their elimination enhances remyelination in young mice but not in aged mice. In young mice, we observed the upregulation of senescence-associated transcripts primarily in microglia after demyelination, followed by their reduction during remyelination. However, in aged mice, senescence-associated factors persisted within lesions, correlating with inefficient remyelination. We found that SC elimination enhanced remyelination in young mice but was ineffective in aged mice. Proteomic analysis of senescence-associated secretory phenotype (SASP) revealed elevated levels of CCL11/Eotaxin-1 in lesions, which was found to inhibit efficient oligodendrocyte maturation. These results suggest therapeutic targeting of SASP components, such as CCL11, may improve remyelination in aging and MS.

neuroscience↗

bioRxiv2023

Alzheimer's disease associated isoforms of human CD33 distinctively modulate microglial cell responses in 5XFAD mice

Microglia play diverse pathophysiological roles in Alzheimers disease (AD), with genetic susceptibility factors skewing microglial cell function to influence AD risk. CD33 is an immunomodulatory receptor associated with AD susceptibility through a single nucleotide polymorphism that modulates mRNA splicing, skewing protein expression from a long protein isoform (CD33M) to a short isoform (CD33m). Understanding how human CD33 isoforms differentially impact microglial cell function in vivo has been challenging due to functional divergence of CD33 between mice and humans. We address this challenge by studying transgenic mice expressing either of the human CD33 isoforms crossed with the 5XFAD mouse model of amyloidosis and find that human CD33 isoforms have opposing effects on the response of microglia to amyloid-{beta} (A{beta}) deposition. Mice expressing CD33M have increased A{beta} levels, mo7re diffuse plaques, fewer disease-associated microglia, and more dystrophic neurites compared to control 5XFAD mice. Conversely, CD33m promotes plaque compaction and microglia-plaque contacts, and minimizes neuritic plaque pathology, highlighting an AD protective role for this isoform. Protective phenotypes driven by CD33m are detected at an earlier timepoint compared to the more aggressive pathology in CD33M mice that appears at a later timepoint, suggesting that CD33m has a more prominent impact on microglia cell function at earlier stages of disease progression. In addition to divergent roles in modulating phagocytosis, scRNAseq and proteomics analyses demonstrate that CD33m+ microglia upregulate nestin, an intermediate filament involved in cell migration, at plaque contact sites. Overall, our work provides new functional insights into how CD33, as a top genetic susceptibility factor for AD, modulates microglial cell function.

neuroscience↗

bioRxiv2023

Mathematical Modeling of PCR with Variable Concentrations of DNA and Taq Polymerase

Polymerase Chain Reaction (PCR) is one of the important techniques in molecular biology for many diagnostics and research applications. In this current theoretical PCR optimization research, out of its seven recipe reagents, two of the important constituents e.g., DNA which might be very rare in forensic cases and polymerase enzyme due to its high cost were mathematically modeled and computationally simulated using MATLAB programming platform. Chemical equations of PCR stages were established using the law of mass action followed by differential equations derivations from each of the DNA amplification phases. Firstly, a mathematical model of Taq polymerase enzyme with its variable concentrations ranging from 0.05-0.35 IU/L was formulated which showed the best PCR product of 0.61 ng/L obtained with 0.2 IU/L of polymerase. Similarly, by fixing the optimal polymerase concentration obtained in the previous simulation, the prime-DNA variable concentrations ranging from 0.5-3.5 ng/L were further simulated which showed the best PCR product of 0.94 ng/L at 2.0 ng/L of DNA. PCR wet-lab experimentation and gel-electrophoresis visualization validated mathematically simulated optimized concentrations of the aforementioned two reagents which vary the PCR product considerably. Current findings indicate that mathematically optimized concentrations of Taq-polymerase and template-DNA may reduce the PCR cost, time and energy, but other factors of target-sequence specificity, purity/concentrations of the other reagents, working hygiene, technical intricacies, biosafety and biosecurity factors may also contribute the desired yield of the amplicon.

bioengineering↗

bioRxiv2022

Genomic Selection Pressure Discovery using Site-Frequency Spectrum & Reduced Local- Variability Statistics in Pakistani Dera-Din-Panah Goat

Population geneticists have long sought to comprehend various selection traces present in the goat genome due to natural or human-driven selection and breeding practices. As a step forward to pinpoint the selection signals in the Pakistani Dera-Din-Panah (DDP) goat breed, whole-genome pooled-sequencing (n=12) was performed and 618,236,192 clean paired-end reads were mapped against ARS1 reference goat assembly. Five different selection signal statistics were applied here using four Site-Frequency Spectrum (SFS) methods (Tajimas D (TD), Fay & Wus H (H), Zengs E (E), Pool - HMM) and one Reduced Local-Variability approach named pooled-heterozygosity (Hp). The under-selection regions were annotated with significant threshold values of -ZTD[≥]4.7, -ZH[≥]6, -ZE[≥]2.5, Pool-HMM[≥]12, and -ZHp[≥]5, which resulted in accumulative 364 candidate gene hits, while the highest signals were observed on Chr. 4, 6, 10, 12, 15, 16, 18, 20, 27 harbor ADAMTS6, CWC27 genes associated with body-height, RELN, MYCBP2, FGF14, STIM1, CFAP74, GNB1, CALML6, TMEM52, FAM149A, NADK, MMP23B, OPN3 with body-weight/meat production, FH, MFHAS1, KLKB1 with milk production, RRM1, KMO, SPEF2, F11 with fecundity rate/reproduction, ATP8B4 with immunity, KIT, KMO with pigmentation, ERI1 with olfaction and RHOG with wool production traits. Furthermore, we accentuate to highlight the putative windows that were captured commonly by any of the five statistical methods applied which harbor meat production, immunity and reproduction-associated genes validating the genotype-phenotype relationship of aforementioned traits private to this goat breed. Current insight into the genomic architecture of DDP goat provides a better understanding to improve its genetic potential and other vested traits of large body size and fiber production by updating the breeding strategies to boost the livestock-based agricultural economy of the country.

genetics↗

bioRxiv2021

Differential Gene Expression Pipeline for Whole Transcriptome RNA-Seq Data using Personal Computer

Advances in the next generation sequencing (NGS) technologies, their cost effectiveness and well-developed pipelines using computational tools/softwares has allowed researchers to reveal ground-breaking discoveries in multi-omics data analysis. However, there is still uncertainty due to massive upsurge in parallel tools and difficulty in choosing best practiced pipeline for expression profiling of RNA sequenced (RNA-seq) data. Here, we detail the optimized pipeline that works at a fast pace with enhanced accuracy on personal computer rather than using cloud or high-performance computing clusters (HPC). The steps include quality check, base filtration, quasi-mapping, quantification of samples, estimation and counting of transcript/gene expression abundances, identification and clustering of differentially expressed features and visualization of the data. The tools FastQC, Trimmomatic, Salmon and some other scripts in Trinity toolkit were applied on two paired-end datasets. An extension of this pipeline may also be formulated in future for the gene ontology enrichment analysis and functional annotation of the differential expression matrix to make this data biologically more significant.

bioinformatics↗

bioRxiv2021

Whole Genome Selective Sweeps Analysis in Pakistani Kamori Goat

Natural and artificial selection fix certain genomic regions of reduce heterozygosity which is an initial process in breed development. Primary goal of the current study is to identify these genomic selection signatures under positive selection and harbor genes in Pakistani Kamori goat breed. High throughput whole genome pooled-seq of Kamori (n = 12) and Bezoar (n = 8) was carried out. Raw fastq files were undergone quality checks, trimming and mapping process against ARS1 reference followed by calling variant allele frequencies. Selection sweeps were identified by applying pooled heterozygosity (Hp) and Tajimas D (TD) on Kamori while regions under divergent selection between Kamori & Bezoar were observed by Fixation Index (FST) analysis. Genome sequencing yielded 619,031,812 reads of which, 616,624,284 were successfully mapped. Total 98,574 autosomal selection signals were detected; 32,838 from Hp and 32,868 from each FST & TD statistics. Annotation of the regions with threshold (-ZHp [≥] 5, TD [≤] -2.72 & FST [≤] 0.09) detected 60 candidate genes. The top hits harbor Chr.1, 6, 8 & 21 having genes associated with body weight (GLIS3, ASTE1), coat color (DOCK8, MIPOL1) & body height (SLC25A21). Other significant windows harbor milk production, wool production, immunity, adaptation and reproduction trait related genes. Current finding highlighted the under-selection genomic regions of Kamori breed and likely to be associated with its vested traits and further useful in breed improvement, and may be also propagated to other undefined goat breeds by adopting targeted breeding policies to improve the genetic potential of this valued species.

genomics↗