Biology subjects

Hadebe, S.

Publications and source records attributed to Hadebe, S..

3 recordsLinked to original sources

bioRxiv2026

Draft genome assembly of the Woolly bottlebrush (Greyia radlkoferi) using Pacbio long-read sequencing technology.

The Woolly bottlebrush (Greyia radlkoferi) is an indigenous South African plant known for its ornamental appeal and potential medicinal uses. It naturally grows on rocky hillsides and grasslands and highly resilient to drought, temperature fluctuations, and nutrient-poor soils. Its flavonoid-rich compounds with anti-tyrosinase activity support its traditional use to treat skin pigmentation disorders in humans. Despite its outstanding ecological and biochemical characteristics, no reference genome is available for Greyia radlkoferi. Therefore, this study aimed to generate the first draft genome of the Greyia Radlkofleri using PacBio Sequel IIe HiFi long read sequencing. A total of 56.07 Gb HiFi data was generated, providing a total genome coverage of 270X. The assembled genome size was 206Mb, with the longest scaffold being 13.9 Mb. The assembly statistics yielded a scaffold and contig N50 of 10.1 Mb, and an L50 of 9, and with an overall GC content of 34.9 %. The genome scope profile set at kmer = 17 indicated that the genome is triploid. The genome annotation predicted 17,804 protein-coding genes and 17,804 transcripts with an average gene length of 3,116.03 bp. This is the first draft genome of its kind for the Greyia genus and provides a foundation for future studies aimed at elucidating the genetic basis of its environmental resilience and the biosynthetic pathways underlying its medicinal properties.

genomics↗

bioRxiv2026

Chromosome-level Genome Assembly of the South African Lion (Panthera leo melanochaita)

The lion (Panthera leo melanochaita) is one of the most iconic species and part of the big five, maintaining ecological balance and a major wildlife-based tourism attraction in South Africa. Despite its importance, it is currently threatened by rapid population decline and increasing population fragmentation. Therefore, there is a need for a high-quality genomic resource that captures the diverse genetic landscape of South African lion populations. To address this, we present a high-quality genome assembly of the lion, generated using PacBio HiFi and Omni-C sequencing technologies. The final assembly comprises 2.45 Gb, with a scaffold N50 of 148 Mb and a contig N50 of 22 Mb. Remarkably, 94.8% of the genome is anchored to 19 scaffolds, reflecting the high degree of contiguity and near-complete chromosomal level. Completeness assessment of the genome showed 98.2% BUSCO, 98.2% k-mer completeness and QV of 65.6 underscoring high accuracy and biological integrity. Genome annotation predicted 831.4 Mb (33.9%) of repetitive sequences and 21 739 protein-coding genes. This work provides high-quality genomic resource to establish a foundation for future population genomic and conservation-focused investigations of the lion populations in South Africa.

genomics↗

bioRxiv2023

Immunoglobulin M regulates airway hyperresponsiveness independent of T helper 2 allergic inflammation.

Allergic asthma is a disease driven by T helper 2 (Th2) cells, eosinophilia, airway hyperresponsiveness (AHR) and IgE-secreting B cells. Asthma is largely controlled by corticosteroids and {beta}2 adregenic receptor agonists that target and relax airway smooth muscle (ASM). Immunoglobulin M (IgM) isotype secreted by naive B cells is important for class switching but may have other undefined functions. We investigated the role of IgM in a house dust mite (HDM)-induced Th2 allergic asthma model. We sensitised wild-type (WT) and IgM-deficient (IgM KO) mice with HDM and measured AHR, and Th2 responses. We performed RNA sequencing on the whole lung of WT and IgM KO mice sensitised to saline or HDM. We validated our AHR data on human ASM by deleting genes using CRISPR and measuring contraction by single-cell force cytometry. We found IgM to be essential in AHR but not Th2 airway inflammation or eosinophilia. RNA sequencing of lung tissue suggested that IgM regulated AHR through modulating brain-specific angiogenesis inhibitor 1-associated protein 2-like protein 1 (Baiap2l1) and other genes. Deletion of BAIAP2L1 led to a differential reduction in human ASM contraction when stimulated with TNF- and Acetylcholine, but not IL-13. These findings have implications for future treatment of asthma beyond current therapies.

immunology↗