HOW THE BELGIAN NFP-GTI HAS HELPED MY WORK
- My Project Title:
DNA Characterizations Towards Description of Various New Muroid Rodent Taxa from
Southwestern Nigeria
- My Name:
Ayodeji Olayemi
Natural History Museum
Obafemi Awolowo University
Ile Ife
- My Country:
Nigeria
- My Taxon:
Muroid rodents
- My Training Location:
Royal Belgian Institute of Natural Sciences, Brussels
- The Duration of My Training?
1 month, in March 2005; and 1 month in October, 2008
- How the support of the Belgian GTI Advanced My Career:
During the course of my PhD, in March 2005, I was awarded a grant by the National Focal Point
to the Global Taxonomy Initiative (NFP-GTI) in Belgium to attend a course on Rodent Taxonomy
and Collection Management. Amongst other taxonomic procedures, the most significant aspect of
this course was that I learned molecular techniques to enable accurate identification of my rodent
specimens. This fellowship involved hands-on laboratory sessions primarily at the Royal Belgian
Institute of Natural Sciences, Brussels, but also at the Royal Museum for Central Africa,
Tervuren, and the University of Antwerp, where I learned techniques involving DNA extraction
from my rodent tissues, amplification of the cytochrome b gene region by Polymerase Chain
Reaction (PCR), and nucleotide sequencing (Fig. 1).
A
Fig. 1
(A)
(B)
B
Extracting DNA from my rodent tissue samples at the molecular laboratory of the Royal
Belgian Institute of Natural Sciences.
Observing the results of my PCR on an eletrophoretic gel with another trainee
Findings from the analyses carried out during this fellowship indicate that most of the rodent
populations sampled from southwestern Nigeria are heterogeneous in comparison to other
populations currently grouped under the same species across West Africa and other parts of the
African continent. These results are now leading to a revision of the taxonomic statuses of the
Nigerian populations.
For instance, comparison of my Spotted Grass mouse DNA sequences from southwestern
Nigeria to those from other parts of sub-Saharan Africa have led to clarification of the status of
this population, establishing it as a conspecific but distinct clade within the species Lemniscomys
striatus (Nicolas et al., 2008). These comparisons have also led to revision of the status of the
Soft-furred rat (genus Praomys) population within the forest of southwestern Nigeria, which was
mistakenly up to now thought to be P. tullbergi, and closer phylogenetically to populations under
the same name that lie towards western Africa. My molecular data show that this population
instead is P. misonnei and closer phylogenetically to other populations of P. misonnei that lie
toward central- and eastern Africa (Nicolas et al., in press).
Late last year in November 2008 I won another NFP-GTI fellowship to visit Belgium to conduct
further research concerning rodent taxonomy. These studies, in conjunction with my
collaborators, have led to the description of a new species of Hylomyscus spanning southwestern
Nigeria and Benin Republic from specimens that have hitherto been known as the Stella Wood
mouse, H. stella (Nicolas et al., in preparation). Our molecular investigations, employing
sequences from the Giant pouched rat (genus Cricetomys) across localities spanning much of
sub-Saharan Africa, have also provided evidence that overturn perceptions currently held about
phylogenetic relationships between major clades within this genus, and indicate the presence of
at least one new species to be described from the forest zone of western Africa (Olayemi et al.,
in preparation).
Apart from the publications that are now emanating from the molecular data I was able to
prepare, other achievements and opportunities have become possible to me as a result of the
study visits I benefited from that were organized by the Belgian NFP-GTI. I was able to complete
my PhD programme (Olayemi, 2007), which involved comparisons of my molecular data to the
morphometric and distributional data I had previously gathered on muroid rodents from
southwestern Nigeria (now published in Olayemi & Akinpelu, 2008a & b). I was also able to
present findings from my DNA data at an international conference, the African Small Mammal
Symposium in Benin, 2007, under the title, “Various Murid Rodents from Nigeria Represent
Cryptic, Previously Undescribed Taxa: Preliminary DNA Evidence” (Olayemi et al. 2007; Fig 2).
Fig 2:
Presenting results on DNA taxonomy from my rodents specimens at an international
conference, the African Small mammal Symposium, in August 2007
Also, based on my newly-acquired expertise on molecular techniques and analysis, I was invited
to participate in the Consortium for the Barcode of Life (CBOL) conference for West and Central
Africa in 2008 as a Nigerian delegate. During that meeting I played a part in preparing the
“National Report of DNA barcoding Activities in Nigeria”. Presently, my skills in molecular analysis
have provided me the prospect of participating in a project investigating the ecology of
transmission of the deadly Lassa virus from rodents to Man across various localities in Nigeria.
The expertise I’ve acquired and the support I’ve benefited from the Belgian NFP-GTI has indeed
helped me to become more effective in my work as a taxonomist, and has assisted in
accomplishing research that is vital toward the conservation and management of the unique small
mammal diversity located within southwestern Nigeria.
References
Olayemi, A. (2007) Taxonomic Evaluation by Morphometric Analysis of Muroid Rodents
from parts of South Western Nigeria. PhD Thesis, Department of Zoology, Obafemi
Awolowo University, Ile Ife, Osun State, Nigeria
Olayemi, A. and A. Akinpelu (2008a) Morphometric characterization of the Giant
pouched rat (Cricetomys Waterhouse 1840) in the forest zone of south western Nigeria.
Mammalia 72: 229-236. http://www.referenceglobal.com/doi/pdf/10.1515/MAMM.2008.024
Olayemi, A. and A. Akinpelu (2008b) Diversity and distribution of murid rodent
populations between forest and derived savanna sites within south western Nigeria.
Biodiversity and Conservation 17: 2411-2425.
http://www.springerlink.com/content/a501861263502740/
Olayemi, A., Nicolas, V., Colyn, M., Leirs, H. and E. Verheyen (2007) Various murid rodents from
Nigeria represent cryptic, previously undescribed taxa: preliminary DNA evidence. Poster
presentation. 10th International African Small Mammal Symposium, International Institute
of Tropical Agriculture. Abomey-Calavi, Republic of Benin, 20-25th August, 2007
Nicolas, V., Mboumba, J. F., Verheyen, E., Denys, C., Lecompte, E., Olayemi,
A., and M. Colyn (2008) Phylogeographical structure and regional history of
Lemniscomys striatus (Rodentia: Muridae) in tropical Africa. Journal of Biogeography 35:
2074-2089. http://www3.interscience.wiley.com/cgi-bin/fulltext/121375780/PDFSTART
Nicolas, V., Akpatou, B., Wendelen, W., Kerbis-Peterhans, J., Olayemi, A.,
Decher, J., Isaquou, D., Missoup, A. D., Denys, C., Barriere, P., Cruaud, C. and M. Colyn
(In press) Molecular and morphometric variation in two sibling species of the genus
Praomys (Rodentia: Muridae): implications for biogeography Zoological Journal of the
Linnean Society