Search bioRxiv⌕ Search

Biology subjects

Njoroge, R.

Publications and source records attributed to Njoroge, R..

2 recordsLinked to original sources

Unbiased whole genome comparison of Pan paniscus (bonobo) and Homo sapiens (human) through a novel sequence match-based approach

Due to technical and computational limitations, original attempts to compare humans to other non-human primates (NHP) were restricted to specific gene and protein comparisons. With the advances in supercomputing and whole genome sequencing technology, these studies can be revisited to explore entire genomes unbiasedly. A novel alignment-dependent homology algorithm that utilizes a linear search-based approach to find segments of homolog sequences based on a given length of word size, ranging from 32 bp to 1000 bp, was used to perform whole genome comparisons. These sequences were then compared over each chromosome of both the target and control species. Chromosome similarities between Pan paniscus and Homo sapiens varied greatly across various chromosomes. At 32-bp granularity, chromosome 3 showed the highest similarity (91.96%), while chromosome 5 showed the lowest similarity (59.66%). Overall, this indicates that while there are significant similarities in the anatomical structures, physiological structures, and protein similarities, there are significant differences in the genomic code between the two species. Additionally, not all sequences are conserved equally, underscoring the need to study the role that gene duplications, transpositions, and horizontal gene transfer may play in species divergence.

bioinformatics↗

Agroforestry adoption and its influence on soil quality under smallholder maize production systems in western Kenya

Agroforestry, a sustainable land use practice was-introduced in western Kenya in the early 1990s as a soil fertility replenishment strategy alongside other multiple benefits. Since then, effect of the practice on soil quality is seldom evidenced. Therefore, a study was conducted in the region to assess the effects of agroforestry adoption on soil quality under small holder maize production systems. A total of 120 soil samples were collected from two land use practices: agroforestry adoption (90) and non-agroforestry adoption (30) at 0-30 cm depth from two locations (Busia and Kakamega counties). On average, adoption of agroforestry significantly improved soil physicochemical properties compared to non-adoption of agroforestry. Bulk density (BD) reduced by 21% (from 1.4 to1.1g cm-3) while SOC increased by 75% (0.8-1.4%), P by 80% (3.0-5.4 mg kg-1), exchangeable K+ by 256% (0.3-8.0 Cmolc kg-1), Ca2+ by 100% (1.0-2.0 Cmolc kg-1), S by 50%(0.2-0.3 mg kg-1), and Cu by 18% (2.8-3.3 mg kg-1).In reference to the soil environmental requirement for maize production, agroforestry adoption significantly increased K and Cu above the critical thresholds of 0.4 Cmolc kg-1 and 1.0 mg kg-1, respectively regardless of the study location or adoption practice. In addition, different agroforestry tree species had variable effect on soil properties. Sesbania and leucaena significantly influenced soil BD, clay, pH, Similarly, soil available P (4.3.-7.0 mg kg -1), exchangeable K+ (0.4-0.7 cmolc kg-1), Mg (0.1-0.2 cmolc kg-1), and Mn (13.5 - 25.2 mg kg-1) above non-agroforestry adoption at both locations, while calliandra significantly increased SOC in Kakamega only.

ecology↗