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Understanding the level of genetic diversity in any population is an important requisite towards strategizing measures for conservation and improvement of stocks. This study focused on the assessment of phylogenetics and molecular divergence of tilapia fish species obtained from two populations (Domita in South-South and Odeda in South-West, Nigeria) using the displacement loop (D-loop) and cytochrome b region of the mitochondrial deoxyribonucleic acid (mtDNA). A total of 28 samples (15 from South-South and 13 from South-West) were used for the genetic analysis. DNA was extracted from the tissue of all the samples using Quik-gDNATM miniPrep kit. The D-loop containing the hypervariable region was sequenced for all samples from the two populations, while cytochrome b (Cyt b) region of mtDNA was only sequenced for samples from South-South population. Chromatograms of the sequences were viewed and edited using Bioedit software. Multiple sequence alignment was carried out using molecular evolutionary genetic analysis (MEGA) software before subsequent genetic analyses. Phylogenetic analysis grouped the samples into two clusters based on population. Also, when the two mitochondrial regions were pooled together, they clustered into two major groups based on mitochondrial regions. Analysis of molecular variance (AMOVA) revealed 37.32% variation within population and 62.68% variation among population with a significant fixation index of 0.627 (p < 0.05). The genetic distance inferred between D-loop regions of South-South and South-West populations was 0.243. Maternal lineage analysis revealed that the origin of tilapia fish from both populations could be traced to Oreochromis spirilus and Oreochromis leucostictus based on mitochondrial D-loop region. The findings of this study revealed molecular divergence among the tilapia populations and may serve as pivot information for the genetic improvement of this important species.

Aim: The aims are to study the genetic diversity and population structure of Tilapia fish species in Nigeria using mtDNA D-loop region and time divergence of these various groups of fish to give a baseline information for fish management and conservation programs. Methodology: Blood samples from four species of tilapia were collected with the use of FTA cards for DNA extraction and PCR amplification. A 941bp long fragment, including the D-loop, was subsequently used for analysis. Molecular diversity indices and Tajima’s selective test were determined. A phylogenetic tree was constructed for all the four fish species using UPGMA. The divergence time among the four fish species using MEGA5 software.

In this study, the maternal genetic diversity, phylogenetic relationship and effect of natural selection on indigenous chickens from Nigeria were assessed. A total of 397-bp fragment of the mitochondrial DNA (mtDNA) D-loop region of 171 indigenous chickens from four populations of Nigeria and four commercial egg line strains (two Anak titan, one Giriraja and one Yaffa) as out-groups were analysed. Thirty-one haplotypes (28 from Nigerian chickens and three from commercial strains) and 34 polymorphic sites were identified. The mean haplotypic and nucleotide diversity were found to be 0.39 ± 0.05 and 0.02 ± 0.02, respectively. Majority of Nigerian chicken haplotypes observed were grouped into haplogroup D which originated from Indian subcontinent, suggesting a single maternal lineage. Genetic variation within and between populations accounted for 97.30 and 2.70% of the total genetic variation, respectively, which is in agreement with a recent and maternal founding effect. High number (4) of negatively selected sites observed based on single likelihood ancestral counting (SLAC) model indicated that the sampled Nigerian chicken populations were undergoing purifying selection. This study concluded that there was relatively high genetic diversity and differentiation, thus, this information will probably paveway for further evaluation studies, preservation and improvement of Nigerian chickens as genetic resources towards ensuring food security.

Mitochondrial DNA (mtDNA) hypervariable region 1 ( HV1) sequences of three Nigerian indigenous goat breeds; West African Dwarf (WAD), Red Sokoto (RS) and Sahel were used to investigate the genetic diversity and effect of selection between and among these populations. Deoxyribonucleic acid (DNA) of Nigerian indigenous chicken was extracted from blood samples collected and preserved on Fast Technology for Analysis (FTA) paper. The extracted DNA were amplified and sequenced with predefined mitochondria (mtDNA) primer sets for HV1. Eighty-seven (87) polymorphic sites were found in 115 sequences which were grouped into 92 haplotypes. The mean haplotypic and nucleotide diversity were found to be 0.996±0.002 and 0.092±0.04 respectively. Genetic variation within population and between populations accounted for 97.26% and 2.74% of the total maternal variation respectively, with FST value of 0.0274. The Tajima's (D) and Fu's (F) test of neutrality were significant (P

In this study, the maternal genetic diversity and phylogenetic relationship of Nigerian duck populations were assessed. A total of 591 base pair fragment of the mitochondrial DNA (mtDNA) D-loop region of 87 indigenous ducks from two populations in Nigeria were analyzed. Seven haplotypes and 70 polymorphic sites were identified. The mean haplotypic and nucleotide diversity were found to be 0.381±0.058 and 0.315±0.155 respectively. The phylogeny revealed two divergent haplotype clades, suggesting two possible maternal lineage in Nigerian duck population, with the most commonly shared haplotype belonging to Mallard ducks ( Anas platyrhynchos ). Genetic variation within and between populations accounted for 63.32% and 36.68% of the total genetic variation respectively. This study concluded that there was relatively high genetic diversity and differentiation, thus, this information will probably pave way for further evaluation studies, preservation and improvement of Nigerian ducks as genetic resources. Keywords : Genetic Diversity, MtDNA, Nigerian duck, phylogeny

Egeria radiata is a benthic species of bivalves which inhabits freshwater bodies along the coast of Nigeria. It’s an edible species with shells of nutrient value used in animal feeds and healthcare industries. This research was undertaken to investigate its species diversity in some coastal populations in Nigeria. Partial sequence of Cytochrome b region of mitochondrial DNA extracted from 53 samples from three locations (Itu 17, Southern Ijaw 18 and Burutu 18) in the Niger delta region of Nigeria were sequenced, aligned and subjected to haplotype network analysis. Afterwards, MEGA 6.06 was used in the analysis of genetic distance, selection and some diversity-based parameters. Results showed high transversion and non-synonymous substitution in Itu population. Polymorphic sites and haplotype diversity was high across the populations (0.88 [Image: see text] ” 0.96), indicating considerable diversity of the sequences. Nucleotide diversity was highest in Itu population. Graphical display of relationship among the haplotypes of pooled samples did not show population-based discrimination. Within-population genetic distance was least in Burutu (0.003), while between-population genetic distance was least between Burutu and Southern Ijaw (0.014). In addition, diversity indicated by genetic distance and diversity indices was not severe. Phylogenetics and median-joining network analyses did not segregate the populations into well-defined clades. Selection analysis revealed large site indices for both positive and negative selection in Itu, but more of neutral selection in the other two populations. Tajima’s D and Fu’s F values for neutrality test showed no significance difference (P>0.01) in each case. However, negative D value was obtained for the three populations. The rate of population growth or expansion was higher in Burutu than Itu and Southern Ijaw. Egeria radiata showed no maternal relationship with the other bivalve species based on the cytochrome b gene region used in this study.