Biology subjects

Minhas, R.

Publications and source records attributed to Minhas, R..

4 recordsLinked to original sources

bioRxiv2026

Chromosome-level assembly of the Arabian killifish as a novel biomedical model species.

The Arabian killifish (Aphaniops dispar) is an excellent model for studying human diseases such as fungal infections and cancer progression. The embryos possess a transparent chorion for live imaging and display an extended period of independent feeding (13 days post-fertilisation). They also exhibit broad thermal tolerance which enables live imaging at physiologically relevant human temperatures. However, omics resources for this species remain limited and restricts its use in genomics studies. We generated a 1.45 GB high-quality reference assembly with 24 chromosome-level scaffolds and N50 score of 60.64 Mb by combining long-read, long-range, and short-read sequencing. The A. dispar genome exhibits a high level of homozygosity (95.6%) with BUSCO gene completeness scores of 99.2% and 97.5% for the Actinopterygii and Cyprinodontiformes lineages, respectively. The genome is highly repetitive (58.7%) and the majority of these are DNA transposons. The mitochondrial genome is 81.55% similar to that of Aphanius iberus (the Spanish toothcarp), with minor structural modifications. A. dispar exhibits highly conserved synteny with Fundulus heteroclitus within the Cyprinodontoidei clade. Together, these findings provide a valuable genomic resource for comparative genomics within the teleost community.

genomics↗

bioRxiv2026

Title: A de novo transcriptomic atlas of early embryo development in the Arabian killifish

The Arabian killifish (Aphaniops dispar) is new tractable vertebrate model system for developmental, ecological and biomedical research, including drug screening, pharmacological and infection biology studies. It is a relatively small euryhaline teleost with broad thermal tolerance and adaptability across a wide range of salinities from freshwater to hypersaline habitats. The embryos and early larvae are tolerant to environmental stressors and exhibit a delayed period of nutritional independence before hatching. This advantage offers an extended window for experimenting on the early developmental processes. Here, we describe time-course gene expression profiling of Arabian killifish embryos across nine developmental time points, from the 1-cell stage to the larval pre-hatching stage. Clustering of dynamic expression profiles for 27,564 Trinity genes revealed coordinated transcriptional modules corresponding to the maternal, blastula, maternal-to-zygotic transition (MZT)-related, gastrulation, organogenesis and larval maturation stages. The maternal stage displayed a highly distinct expression profile, dominated by maternal-specific transcripts that are rapidly degraded during the MZT. The later stages, from 48 hpf onward, revealed a shift from early regulatory mechanisms to the expression of organogenesis-related genes. The ZGA stage showed the conserved up-regulation of many zinc finger-associated genes, consistent with zebrafish and other teleost genomes. Overall, embryo development in A. dispar is slower than in zebrafish, with equivalent stages occurring several hours later. We propose a delayed onset of zygotic genome activation (ZGA) in the blastula stage, corresponding to 6 hpf in the Arabian killifish. Taken together, this study provides a transcriptomic resource for mining embryo development-related genes in the Arabian killifish.

genomics↗

bioRxiv2024

Melanophore and fluoroleucophore synergistically photo-protect the Arabian killifish, Aphanius dispar, embryo from ultraviolet light

Pigment cells in fish species play crucial roles in forming colour patterns of each species and other physiological characteristics including photoprotection. Research on photoprotection by pigment cells in animals has primarily concentrated on black pigment cells, known as melanophores. However, the roles of other pigment cells and their synergistic effects on UV protection remain poorly understood. In this study, we use the Arabian killifish embryos as a model for studying the mechanisms of UV protection by different pigment cells. This species features highly fluorescent pigment cells called fluoroleucophores and black pigment cells known as melanophores. The fluorescent pigments and black melanin pigments are generated by genes gch (GTP cyclohydrolase) and tyr (tyrosinase) respectively. We generated gch(-/-) and gch/tyr(-/-) double mutant lines using CRISPR/Cas9 genome editing and examined the UV sensitivity of these mutant embryos. Both morphology and gene expression data revealed that the gch/tyr(-/-) double mutant line exhibited the highest UV sensitivity, and the gch(-/-) line also demonstrated a greater stress response compared to wild type (WT). From the study, we have identified the synergistic role of black and fluorescent pigment cells in providing effective UV protection from the early stages of embryonic development.

developmental biology↗

bioRxiv2024

The thermotolerant Arabian killifish, Aphanius dispar, as a novel infection model for human fungal pathogens

Candida albicans: a fungal pathogen, can cause superficial and fatal infections in humans. An important virulence factor in C. albicans dissemination is the transformation from yeast to an invasive hyphal form, which is favoured at human body temperature. Zebrafish, a useful model for studying C. albicans infections, cannot survive at 37{degrees}C. Arabian killifish, Aphanius dispar, an emerging teleost model can tolerate temperatures up to 40 {degrees}C for up to 12 days (independent feeding time) allowing for longer analysis compared to zebrafish. This study introduces A. dispar as a thermo-relevant and a more accurate reporter of the virulence mechanisms relevant to C. albicans as a human pathogen. Using A. dispar, we tested virulence at human skin (30 {degrees}C), body temperature (37 {degrees}C) and a high fever condition (40{degrees}C). Infection by C. albicans at 37{degrees}C and 40{degrees}C significantly increased virulence, reduced survival of AKF embryos and formed invasive hyphal network compared to 30 {degrees}C. Two mutant strains of C. albicans. pmr1{Delta} (with aberrant cell surface glycans) exhibited reduced virulence at 37{degrees}C, whereas rsr1{Delta} (lacking a cell polarity marker) showed less virulence at 30 {degrees}C. Additionally, anti-fungal treatment rescued AKF survival in a dose-dependent manner, indicating AKFs potential for in vivo drug testing. Our data indicates the quantitative and qualitative importance of examining virulence traits at physiologically relevant temperatures and demonstrates an equivalence to findings for systemic infection derived in mouse models. The A. dispar embryo therefore provides an excellent in vivo model system for assessing virulence, drug-testing, and real-time imaging of host-pathogen interactions. Significance StatementThe virulence of many pathogens is dependent on host temperature. We demonstrate that the A. dispar embryo provides an excellent new thermo-relevant alternative to zebrafish and mouse models, which have limitations in terms of the range of temperatures that can be assessed in real-time. In this study, we have assessed C. albicans temperature-based virulence, focusing on human body and human skin temperatures (37, 40 and 30 {degrees}C, respectively) by examining different genetic backgrounds of C. albicans strains. The results indicate different C. albicans strains with genetic background show varied virulence depending on temperature indicating importance of examination of virulence mechanisms at physiological temperatures.

animal behavior and cognition↗