Sokefun Olusola | Lagos State University, Lagos, Nigeria (original) (raw)

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Papers by Sokefun Olusola

Research paper thumbnail of Disentangling earthworm taxonomic stumbling blocks using molecular markers

Journal of Threatened Taxa, 2021

Taxonomic classification of earthworms based on anatomical features has created several challenge... more Taxonomic classification of earthworms based on anatomical features has created several challenges for systematics and population genetics. This study examines the application of molecular markers, in particular mitochondrial cytochrome oxidase (COI), to facilitate discrimination of closely related earthworm species. Molecular markers have also provided insights into population genetics by aiding assessment of genetic diversity, lineage sorting, and genealogical distributions of populations for several species. Phylogeography—a study that evaluates the geographical distribution of these genealogical lineages and the role of historical processes in shaping their distribution—has also provided insights into ecology and biodiversity. Such studies are also essential to understand the distribution patterns of invasive earthworm species that have been introduced in non-native ecosystems globally. The negative consequences of these invasions on native species include competition for food r...

Research paper thumbnail of Characterization of the Nigerian mudskipper species; Phylogenetic relationship, population structure and DNA barcoding using the Cytochrome oxidase 1 (CO1) gene

Mudskippers are a unique set of organisms being adapted to life both on land and in water. They h... more Mudskippers are a unique set of organisms being adapted to life both on land and in water. They have a worldwide distribution and are very speciose in nature, an indication of their very high adaptability. The Nigeria Mudskipper is herein being barcoded for the first time with interesting results. They form a very unique group mapping together with a very thin genetic diversity with intraspecific genetic diversity being between 0.000-0.009. The average nucleotide composition conforms to that of higher organisms (T (thiamine) 31.8, C (cytosine) 26.1, A (Adenine) 23.5 and G (guanine) 18.6. All the DNA barcodes generated have been deposited in the GenBank (Accession number: OM149397-OM149403). Our result is the first and puts paid to the controversies about what species the Nigerian mudskipper is.

Research paper thumbnail of Papers

DNA barcode analysis of the endangered green turtle (Chelonia mydas) in the breeding grounds of B... more DNA barcode analysis of the endangered green turtle (Chelonia mydas) in the breeding grounds of Badagry,

Research paper thumbnail of Resolving the taxonomic confusion in the Nigeria Snakeheads (Teleostei, Channidae): DNA barcoding of the Lagos lagoon populations

This current study assessed the population of Parachanna obscura from the Lagos lagoon. It is the... more This current study assessed the population of Parachanna obscura from the Lagos lagoon. It is the first study that is examining the usefulness of DNA barcoding in identifying the Lagos Lagoon in Nigeria populations and also shedding more light on their taxonomic status. The CO1 gene yielded consistently 654 base pairs after alignment. Intraspecific divergence is low ranging from 0.00 to 0.05, while interspecific divergence with other available gene sequences is between 0.00 to 0.2. Average nucleotide composition were in the order T > C > A > G (T: 29.1, C: 28.7, A: 22.1 and G: 20.0). There were 648 conserved sites and 4 variable sites. One hundred and five (105) of the sites were polymorphic, with One Hundred and twenty One (121) mutations and a nucleotide diversity of 0.0937, Tajima's diversity of 2.52 at a statistical significance of p<0.05 was also observed. There were fourteen (14) unique haplotypes. The Lagos lagoon population all mapped together with a bootstrap value of 99% indicating some level of uniqueness, even though their genetic diversity is very low. Further research will be required to add more sampling sites around the Lagos lagoon and also more genetic markers with deeper analysis to see if there are population cryptics.

Research paper thumbnail of DNA barcoding for deciphering the evolutionary lineages of five insect pests of horticultural crops in Ikorodu local government area of Lagos state, Nigeria

Arthropod pest management is dependent on the proper identification of species as quickly as poss... more Arthropod pest management is dependent on the proper identification of species as quickly as possible. Before now, morphology has been the key methodology, resting basically on the use of established taxonomic keys that have suddenly become plastic because of the introduction of new species and the evolution within old one. The development of the DNA barcoding protocol has proven to be of tremendous help as it relies on sequencing a segment of the cytochrome oxidase 1 gene. Where reference gene sequences exists, this technology is exact and can unambiguously identify pests without errors. The method has become very important with Lepidopteran pests which typically wreak havoc at the larva stages when morphological identification is almost impossible. In this research, we have added first genetic information for Alpenus maculosus, Chilo species, Mussidia species and Sesamia calamistis and have further enriched the available reference database upon which further researches can be built. The study also adds quality information to the molecular ecology of Lepidopteran pests around Ikorodu in Lagos State, Nigeria.

Research paper thumbnail of Emerging Research Priorities for the Aquaculture Sector In Sub-Saharan Africa-a Case Study of Nigeria

AACL …, 2009

This paper reviews the role of aquaculture research in Nigeria. The achievements and limitations ... more This paper reviews the role of aquaculture research in Nigeria. The achievements and limitations of research in aquaculture development are discussed. It identifies strategic prioritization of research objectives in three phases namely; the short term, medium term and long term to properly ...

Research paper thumbnail of The cichlid 16S gene as a phylogenetic marker: Limits of its resolution for analyzing global relationship

International Journal of Genetics and Molecular Biology

The phylogenetic utility of the 16S gene in cichlids is assessed. Eighty-six (86) partial sequenc... more The phylogenetic utility of the 16S gene in cichlids is assessed. Eighty-six (86) partial sequences belonging to 37 genera of cichlids from the Genbank was analyzed. The alignment had four hundred and sixty three (463) basepairs with 337 conserved sites and 126 variable sites. Base compositional bias is similar to that found in higher organism with Adenine having the highest average of 30.3%, followed by cytosine, guanine and thiamine with the average values of 26.1, 21.9 and 21.7% respectively. The most suitable evolutionary model is the K2+G+I model as this had the lowest Bayesian Information Criterion. There were 4 major indels at basepair positions 328 which is unique to the Heterotilapia buttikoferi, position 369 unique to Gramatoria lemarii, position 396 which is shared by Tilapia sparrmanii, T. guinasana and T. zilli. The indel at position 373 was found in all tested species except the Oreochromis mossambicus. The Tilapine general is the basal group in Cichlids. The 16S gene separates the Tilapia genera without any ambiguity but there were phylogenetic overlaps in the Sarotherodon and Oreochromis. More finite molecular and statistical methodology may be needed to distinguish the Sarotherodon and Oreochromis. The diversity of cichlids is generally very low due to a common ancestry with little differentiation genetically. The grouping of the Oreochromis and Sarotherodon genera together in the same clade is not unconnected with the preservation of genetic beacons that the group retained as it evolved.

Research paper thumbnail of The cichlid 16S gene as a phylogenetic marker: Limits of its resolution for analyzing global relationship

International Journal of Genetics and Molecular Biology

The phylogenetic utility of the 16S gene in cichlids is assessed. Eighty-six (86) partial sequenc... more The phylogenetic utility of the 16S gene in cichlids is assessed. Eighty-six (86) partial sequences belonging to 37 genera of cichlids from the Genbank was analyzed. The alignment had four hundred and sixty three (463) basepairs with 337 conserved sites and 126 variable sites. Base compositional bias is similar to that found in higher organism with Adenine having the highest average of 30.3%, followed by cytosine, guanine and thiamine with the average values of 26.1, 21.9 and 21.7% respectively. The most suitable evolutionary model is the K2+G+I model as this had the lowest Bayesian Information Criterion. There were 4 major indels at basepair positions 328 which is unique to the Heterotilapia buttikoferi, position 369 unique to Gramatoria lemarii, position 396 which is shared by Tilapia sparrmanii, T. guinasana and T. zilli. The indel at position 373 was found in all tested species except the Oreochromis mossambicus. The Tilapine general is the basal group in Cichlids. The 16S gene separates the Tilapia genera without any ambiguity but there were phylogenetic overlaps in the Sarotherodon and Oreochromis. More finite molecular and statistical methodology may be needed to distinguish the Sarotherodon and Oreochromis. The diversity of cichlids is generally very low due to a common ancestry with little differentiation genetically. The grouping of the Oreochromis and Sarotherodon genera together in the same clade is not unconnected with the preservation of genetic beacons that the group retained as it evolved.

Research paper thumbnail of Disentangling earthworm taxonomic stumbling blocks using molecular markers

Journal of Threatened Taxa, 2021

Taxonomic classification of earthworms based on anatomical features has created several challenge... more Taxonomic classification of earthworms based on anatomical features has created several challenges for systematics and population genetics. This study examines the application of molecular markers, in particular mitochondrial cytochrome oxidase (COI), to facilitate discrimination of closely related earthworm species. Molecular markers have also provided insights into population genetics by aiding assessment of genetic diversity, lineage sorting, and genealogical distributions of populations for several species. Phylogeography—a study that evaluates the geographical distribution of these genealogical lineages and the role of historical processes in shaping their distribution—has also provided insights into ecology and biodiversity. Such studies are also essential to understand the distribution patterns of invasive earthworm species that have been introduced in non-native ecosystems globally. The negative consequences of these invasions on native species include competition for food r...

Research paper thumbnail of Characterization of the Nigerian mudskipper species; Phylogenetic relationship, population structure and DNA barcoding using the Cytochrome oxidase 1 (CO1) gene

Mudskippers are a unique set of organisms being adapted to life both on land and in water. They h... more Mudskippers are a unique set of organisms being adapted to life both on land and in water. They have a worldwide distribution and are very speciose in nature, an indication of their very high adaptability. The Nigeria Mudskipper is herein being barcoded for the first time with interesting results. They form a very unique group mapping together with a very thin genetic diversity with intraspecific genetic diversity being between 0.000-0.009. The average nucleotide composition conforms to that of higher organisms (T (thiamine) 31.8, C (cytosine) 26.1, A (Adenine) 23.5 and G (guanine) 18.6. All the DNA barcodes generated have been deposited in the GenBank (Accession number: OM149397-OM149403). Our result is the first and puts paid to the controversies about what species the Nigerian mudskipper is.

Research paper thumbnail of Papers

DNA barcode analysis of the endangered green turtle (Chelonia mydas) in the breeding grounds of B... more DNA barcode analysis of the endangered green turtle (Chelonia mydas) in the breeding grounds of Badagry,

Research paper thumbnail of Resolving the taxonomic confusion in the Nigeria Snakeheads (Teleostei, Channidae): DNA barcoding of the Lagos lagoon populations

This current study assessed the population of Parachanna obscura from the Lagos lagoon. It is the... more This current study assessed the population of Parachanna obscura from the Lagos lagoon. It is the first study that is examining the usefulness of DNA barcoding in identifying the Lagos Lagoon in Nigeria populations and also shedding more light on their taxonomic status. The CO1 gene yielded consistently 654 base pairs after alignment. Intraspecific divergence is low ranging from 0.00 to 0.05, while interspecific divergence with other available gene sequences is between 0.00 to 0.2. Average nucleotide composition were in the order T > C > A > G (T: 29.1, C: 28.7, A: 22.1 and G: 20.0). There were 648 conserved sites and 4 variable sites. One hundred and five (105) of the sites were polymorphic, with One Hundred and twenty One (121) mutations and a nucleotide diversity of 0.0937, Tajima's diversity of 2.52 at a statistical significance of p<0.05 was also observed. There were fourteen (14) unique haplotypes. The Lagos lagoon population all mapped together with a bootstrap value of 99% indicating some level of uniqueness, even though their genetic diversity is very low. Further research will be required to add more sampling sites around the Lagos lagoon and also more genetic markers with deeper analysis to see if there are population cryptics.

Research paper thumbnail of DNA barcoding for deciphering the evolutionary lineages of five insect pests of horticultural crops in Ikorodu local government area of Lagos state, Nigeria

Arthropod pest management is dependent on the proper identification of species as quickly as poss... more Arthropod pest management is dependent on the proper identification of species as quickly as possible. Before now, morphology has been the key methodology, resting basically on the use of established taxonomic keys that have suddenly become plastic because of the introduction of new species and the evolution within old one. The development of the DNA barcoding protocol has proven to be of tremendous help as it relies on sequencing a segment of the cytochrome oxidase 1 gene. Where reference gene sequences exists, this technology is exact and can unambiguously identify pests without errors. The method has become very important with Lepidopteran pests which typically wreak havoc at the larva stages when morphological identification is almost impossible. In this research, we have added first genetic information for Alpenus maculosus, Chilo species, Mussidia species and Sesamia calamistis and have further enriched the available reference database upon which further researches can be built. The study also adds quality information to the molecular ecology of Lepidopteran pests around Ikorodu in Lagos State, Nigeria.

Research paper thumbnail of Emerging Research Priorities for the Aquaculture Sector In Sub-Saharan Africa-a Case Study of Nigeria

AACL …, 2009

This paper reviews the role of aquaculture research in Nigeria. The achievements and limitations ... more This paper reviews the role of aquaculture research in Nigeria. The achievements and limitations of research in aquaculture development are discussed. It identifies strategic prioritization of research objectives in three phases namely; the short term, medium term and long term to properly ...

Research paper thumbnail of The cichlid 16S gene as a phylogenetic marker: Limits of its resolution for analyzing global relationship

International Journal of Genetics and Molecular Biology

The phylogenetic utility of the 16S gene in cichlids is assessed. Eighty-six (86) partial sequenc... more The phylogenetic utility of the 16S gene in cichlids is assessed. Eighty-six (86) partial sequences belonging to 37 genera of cichlids from the Genbank was analyzed. The alignment had four hundred and sixty three (463) basepairs with 337 conserved sites and 126 variable sites. Base compositional bias is similar to that found in higher organism with Adenine having the highest average of 30.3%, followed by cytosine, guanine and thiamine with the average values of 26.1, 21.9 and 21.7% respectively. The most suitable evolutionary model is the K2+G+I model as this had the lowest Bayesian Information Criterion. There were 4 major indels at basepair positions 328 which is unique to the Heterotilapia buttikoferi, position 369 unique to Gramatoria lemarii, position 396 which is shared by Tilapia sparrmanii, T. guinasana and T. zilli. The indel at position 373 was found in all tested species except the Oreochromis mossambicus. The Tilapine general is the basal group in Cichlids. The 16S gene separates the Tilapia genera without any ambiguity but there were phylogenetic overlaps in the Sarotherodon and Oreochromis. More finite molecular and statistical methodology may be needed to distinguish the Sarotherodon and Oreochromis. The diversity of cichlids is generally very low due to a common ancestry with little differentiation genetically. The grouping of the Oreochromis and Sarotherodon genera together in the same clade is not unconnected with the preservation of genetic beacons that the group retained as it evolved.

Research paper thumbnail of The cichlid 16S gene as a phylogenetic marker: Limits of its resolution for analyzing global relationship

International Journal of Genetics and Molecular Biology

The phylogenetic utility of the 16S gene in cichlids is assessed. Eighty-six (86) partial sequenc... more The phylogenetic utility of the 16S gene in cichlids is assessed. Eighty-six (86) partial sequences belonging to 37 genera of cichlids from the Genbank was analyzed. The alignment had four hundred and sixty three (463) basepairs with 337 conserved sites and 126 variable sites. Base compositional bias is similar to that found in higher organism with Adenine having the highest average of 30.3%, followed by cytosine, guanine and thiamine with the average values of 26.1, 21.9 and 21.7% respectively. The most suitable evolutionary model is the K2+G+I model as this had the lowest Bayesian Information Criterion. There were 4 major indels at basepair positions 328 which is unique to the Heterotilapia buttikoferi, position 369 unique to Gramatoria lemarii, position 396 which is shared by Tilapia sparrmanii, T. guinasana and T. zilli. The indel at position 373 was found in all tested species except the Oreochromis mossambicus. The Tilapine general is the basal group in Cichlids. The 16S gene separates the Tilapia genera without any ambiguity but there were phylogenetic overlaps in the Sarotherodon and Oreochromis. More finite molecular and statistical methodology may be needed to distinguish the Sarotherodon and Oreochromis. The diversity of cichlids is generally very low due to a common ancestry with little differentiation genetically. The grouping of the Oreochromis and Sarotherodon genera together in the same clade is not unconnected with the preservation of genetic beacons that the group retained as it evolved.