Biology subjects

Muhammad, J.

Publications and source records attributed to Muhammad, J..

4 recordsLinked to original sources

bioRxiv2026

Rhizoctonia theobromae isolates causing Vascular-Streak Dieback of Cocoa and Cassava Witches' Broom Disease are likely host-specific, regionally divergent and homothallic

The fastidious basidiomycete Rhizoctonia (Ceratobasidium) theobromae is a biotrophic pathogen that causes Vascular-Streak Dieback (VSD) of Theobroma cacao (cocoa). The fungus has also been identified as the cause of an emergent disease known as Cassava Witches Broom Disease (CWBD) raising concerns that the pathogen is spreading to alternative hosts and to new regions. Interestingly, while VSD of cocoa and CWBD are reported as co-present in several countries, there is currently no evidence for cross-infection between species. The fungus is difficult to culture in vitro due its slow growth and Kochs postulates have not been definitive on either host. The complete fungus life cycle therefore remains enigmatic, though studies have progressed knowledge on pathology within the both the cocoa and cassava hosts. We have conducted limited field trials and sequenced mating (MAT) and ITS loci of isolates from various infected hosts and regions. We hypothesize that (i) genetic variation at MAT loci correlates with region or host (ii) long amplicon ITS sequences between isolates are more definitive for polymorphisms (iii) life-cycle traits of R. theobromae may be inferred from MAT loci (iv) cassava grown under VSD infected cocoa will be infected and develop symptoms of CWBD. We did not find any cross-infection in field trials, and we show that the pathogen is highly homozygous, despite undergoing meiosis, indicating a predominantly homothallic life cycle. Our data indicate that the pathogen is likely host specific and regionally divergent and suggests that host specificity on cocoa and cassava evolved by selection from a common ancestor rather than a host jump.

microbiology↗

bioRxiv2025

Adherence to Lifes Essential 8 Enhances Gut Microbiota Diversity and Cognitive Performance

Emerging evidence suggests a complex interplay among cardiovascular health, gut microbiome composition, and cognitive function. Lifes Essential 8 (LE8), developed by the American Heart Association, includes vital metrics of cardiovascular health, such as diet, physical activity, nicotine exposure, sleep health, body mass index (BMI), blood glucose, blood lipids, and blood pressure. In this study, we analyzed data from 781 participants in the Framingham Heart Study (FHS) to explore the relationship between LE8 adherence, gut microbiota, and cognitive performance. Participants with greater adherence to LE8 demonstrated significantly increased gut microbial diversity (-diversity: Chao1, p = 0.0014; Shannon, p = 0.0071) and distinct microbial compositions ({beta}-diversity: PERMANOVA p = 1e-4). Higher adherence to LE8 was related to an increased abundance of genera Barnesiella and Ruminococcus, while a reduced abundance of Clostridium was associated with higher LE8 adherence. Greater gut microbial diversity (-diversity: Chao1, p = 0.0012; Shannon, p = 0.0066), and beneficial genera like Oscillospira correlated with better global cognitive scores (GCS). Taxonomic overlap analyses revealed microbial taxa that simultaneously influence both LE8 adherence and cognitive outcomes. Mediation analyses indicated that specific taxa, including Barnesiella and Lentisphaerae, mediated the link between LE8 adherence and cognitive performance. These taxa may serve as key modulators in the gut-brain axis, connecting cardiovascular and brain health. Conversely, higher Clostridium abundance was associated with poorer cognitive performance. This study highlights the significance of comprehensive cardiovascular health metrics in shaping gut microbiota and enhancing cognitive resilience. Our findings underscore the therapeutic potential of targeting gut microbiota to mitigate cognitive decline, warranting further exploration through longitudinal and metagenomic studies.

neuroscience↗

bioRxiv2024

Parental assigned chromosomes for cultivated cacao provides insights into genetic architecture underlying responses to Ceratobasidium theobromae

Diseases of Theobroma cacao disrupt cocoa bean supply and economically impact growers. Vascular streak dieback (VSD), caused by Ceratobasidium theobromae, is a new encounter disease of cacao currently contained to southeast Asia and Melanesia. Resistance to VSD has been tested with large progeny trials in Sulawesi, Indonesia, and in Papua New Guinea with the identification of informative quantitative trait loci (QTL). Using a VSD susceptible progeny tree (clone 26), derived from a resistant and susceptible parental cross, we assembled the genome to chromosome-level and discriminated alleles inherited from either resistant or susceptible parents. The parentally phased genomes were annotated for all predicted genes and then specifically for resistance genes of the nucleotide-binding site leucine-rich repeat class (NLR). On investigation, we determined the presence of NLR clusters at informative QTLs, as well as other potential disease response gene candidates. Understanding the genetics underlying resistance and susceptibility to VSD will accelerate the breeding cycle by providing clear targets for molecular screening. Additionally, we provide the first diploid, fully scaffolded and parentally phased genome resource for Theobroma cacao L.

plant biology↗

bioRxiv2023

Prioritization of The Zinc finger domain within BCL11A gene by the Amelioration capability of hemoglobinopathies using CRISPR-Cas9 technology

BCL11A/EVI9, a zinc-finger protein primarily expressed in brain and hematopoietic cells, plays a central role in lymphocyte development, gamma-globin suppression, spinal neuron development, sensory innervation, neuronal polarity, migration, and is associated with microcephaly and dysregulated brain-related genes, offering therapeutic potential for sickle cell disease. The function of the transcriptional regulator is intricately linked to its structural organization, which determines its ability to interact with specific DNA sequences and modulate gene expression. BCL11A boasts multiple domains, including six C2H2 zinc fingers, a C2HC zinc finger, a NuRD-interacting domain, an acidic domain, and a proline-rich domain. In the present study, we delve into the intricate structure and function of the zinc finger domains located in the BCL11A gene, which plays a crucial role in regulating the expression of gamma-globin gene. Specifically, three C2H2-type zinc finger domains, Znf4, Znf5, and Znf6, within BCL11A, are known to bind to DNA. Znf4 and Znf5 demonstrate a significant interaction with the TGACCA motif in the gamma-globin -115 HPFH region sequence, contributing substantially to DNA binding specificity. Although Znf3 and Znf6 also interact with DNA, their contributions are comparatively minor. Employing CRISPR-Cas9 technology, targeted genomic deletions of Znf4 exhibit high efficiency, opening doors for further research. Edited CD34+ cells successfully differentiate into erythrocytes without impairments, underscoring CRISPR-Cas9s suitability for studying gene functions in erythropoiesis. Furthermore, BCL11A knockdown via sgRNAs results in elevated gamma-globin expression, offering a promising therapeutic avenue for beta-hemoglobinopathies. HPLC analysis reveals a substantial increase in HbF levels, particularly upon Znf4 deletion, emphasizing BCL11A gene potential as a therapeutic target. These findings also highlight the connection between the function of BCL11A and its structural organization, which can be modulated, and this insight can potentially be extended to uncover its roles in various other domains.

molecular biology↗