Biology subjects

Sadiq, M. A.

Publications and source records attributed to Sadiq, M. A..

5 recordsLinked to original sources

bioRxiv2025

Infectious Bronchitis: Molecular Detection and Characterization in Live Bird Markets in Jos, Plateau State, Nigeria

Infectious bronchitis virus (IBV), the avian coronavirus, is a highly contagious coronavirus of birds. It mostly affects the respiratory, urinary and reproductive tract, leading to considerable economic losses to the poultry industry as a result of drop in egg production, undesirable egg quality and poor weight gain. Thus, this study aimed to detect and characterize the virus in live bird markets (LBMs) in Plateau State, Nigeria. One hundred pooled of cloacal and tracheal swab samples each were collected from two LBMs in Jos. Viral RNA was extracted and screened for IBV using real-time RT-PCR. Subsequently, hyper-variable region of the spike (S1) gene of positive samples were amplified and sequenced. IBV nucleic acid was detected in 42% (42/100) of the pooled samples. Phylogenetic analysis of the resulting sequences of S1 gene showed that IBV detected in this study were diversified into two distinct genotypes: GI-14, and GI-23. These genotypes were closely related to a Poland strain with over 95% nucleotide identity, forming a common cluster within the GI-23 group. One isolate showed a notable relationship with a previously reported Nigerian isolate, sharing 85% nucleotide identity, and formed a common cluster within the GI-14 group. Overall, this study established the widespread of IBV and therefore recommends continuous surveillance to identify the current circulating strain for possible local vaccine development for effective control measures to mitigate the spread of the virus in the study area and the country at large.

microbiology↗

bioRxiv2024

Spatial structure could explain the maintenance of alternative reproductive tactics in tree cricket males

Trait polymorphisms are widespread in nature, and explaining their stable co-existence is a central problem in ecology and evolution. Alternative reproductive tactics, in which individuals of one or more sex exhibit discrete, discontinuous traits in response to reproductive competition, represent a special case of trait polymorphism in which the traits are often complex, behavioural, and dynamic. Thus, studying how alternative reproductive tactics are maintained may provide general insights into how complex trait polymorphisms are maintained in populations. We construct a spatially explicit individual-based model inspired from extensively collected empirical data to address the mechanisms behind the co-existence of three behavioural alternative reproductive tactics in males of a tree cricket (Oecanthus henryi). Our results show that the co-existence of these tactics over ecological time scales is facilitated by the spatial structure of the landscape they inhabit, which serves to equalize the otherwise unequal mating benefits of the three tactics. We also show that this co-existence is unlikely if spatial aspects of the system are not considered. Our findings highlight the importance of spatial dynamics in understanding ecological and evolutionary processes and underscore the power of integrative approaches that combine models inspired from empirical data.

animal behavior and cognition↗

bioRxiv2023

To call or not to call: Persistence of flexible alternative reproductive tactics in a tree cricket

Alternative reproductive tactics (ARTs) are discrete polymorphisms that help maximise reproductive success. Although flexible ARTs are ubiquitous, theoretical predictions for why flexible ARTs persist over evolutionary time have rarely been empirically tested. We hypothesised that flexible ARTs will persist if they have equal fitness benefits under a range of ecological contexts, or, there are trade-offs between ARTs in different ecological contexts and individuals display the most optimal phenotype in a context-dependent manner. Specifically, we investigated predation risk effects on the expression and fitness consequences of two flexible ARTs: acoustic signalling and being silent, expressed by tree cricket Oecanthus henryi males. In large outdoor enclosures, we exposed natural populations of O. henryi to three different abundances of their predator, the green lynx spider Peucetia viridans. Behavioural observations across successive nights revealed that higher predation risk did not alter the expression levels of the male ARTs, despite crickets experiencing differential risk and survival across treatments. Male crickets demonstrated an equal likelihood of calling or remaining silent on a night. ARTs resulted in similar mating success across differential predation risk, supporting the hypothesis that equal fitness benefits of flexible ARTs under a range of ecological contexts explain their persistence.

ecology↗

bioRxiv2017

Evolution of dispersal syndrome and its corresponding metabolomic changes

Dispersal is one of the strategies for organisms to deal with climate change and habitat degradation. Therefore, investigating the effects of dispersal evolution on natural populations is of considerable interest to ecologists and conservation biologists. Although it is known that dispersal itself can evolve due to selection, the behavioral, life-history and metabolic consequences of dispersal evolution are not well understood. Here we explore these issues by subjecting four outbred laboratory populations of Drosophila melanogaster to selection for increased dispersal. The dispersal-selected populations had similar values of body size, fecundity and longevity as the non-selected lines (controls), but evolved significantly greater locomotor activity, exploratory tendency, and aggression. Untargeted metabolomic fingerprinting through NMR spectroscopy suggested that the selected flies evolved elevated cellular respiration characterized by greater amounts of glucose, AMP and NAD. Concurrent evolution of higher level of Octopamine and other neurotransmitters indicate a possible mechanism for the behavioural changes in the selected lines. We discuss the generalizability of our findings in the context of observations from natural populations. To the best of our knowledge, this is the first report of the evolution of metabolome due to selection for dispersal and its connection to dispersal syndrome evolution.

evolutionary biology↗

bioRxiv2017

Pre-dispersal conditions and presence of opposite sex modulate density dependence and sex bias of dispersal

Density-dependent dispersal (DDD) has been demonstrated in many species and has several ecological and evolutionary consequences. Yet we know little about how robust DDD is to the various conditions experienced by individuals. In this study, we use three independent experiments on laboratory populations of Drosophila melanogaster to examine the effects of pre-dispersal adult density, sex of the dispersers and presence of mates on the robustness of DDD patterns. We show that DDD can be greatly affected by both pre-dispersal density and interaction between the sexes. Moreover, the direction of sex-biased dispersal can reverse completely due to an interaction between the pre-dispersal and dispersal densities. We also show that interaction between the sexes can lead to negative DDD at the population level, even if, by themselves, neither sex exhibits DDD. Finally, we discuss potential implications of our results for processes like evolutionary rescue from extinctions and genetic divergence of populations.

ecology↗