Genetic Differentiation of <i>Archachatina marginata</i> Populations from Three Vegetation Zones Using Radom Amplified Polymorphic DNA Polymerase Chain Reaction

Abstract

The genetic differentiation of Archachatina marginata populations from three different zones of Nigeria was studied with a view to delimiting them into sub-species. One hundred and nineteen (119) snail specimens were collected, comprising of forty (40) specimens from Yenagoa (Mangrove forest) and from Kabba (Guinea Savanna) and thirty nine (39) specimens were from Ile-Ife (Rainforest). Eight parameters of the shell specimens of A. marginata which included height of shell, width of shell, aperture height, aperture width, spire length, spire width, penultimate whorl length and first whorl length were subjected to Principal Component Analysis (PCA) and Canonical Variates Analysis (CVA) to delimit the populations into sub-species. DNA of the various populations was extracted from the foot muscle using CTAB (Cetyl Trimethyl Ammonium Bromide) method, which was subjected to RAPD analysis. The RAPD studies employed five (5) oligonucleotide primers (OPB – 17, OPH – 12, OPH – 17, OPI – 06 and OPU – 14) to amplify DNA from 27 samples of A. marginata selected. All five primers produced different band patterns, and the number of fragments amplified per primer varied. Among them, OPB- 17 gave DNA profiles with more numerous bands than the others primers. Both PCA and CVA produced overlapped clusters of A. marginata specimens from the three vegetation zones. The height of shell was observed to be the most variable feature and preferably the most suitable parameter for population grouping. Analysis of the proportions of polymorphic loci and band sharing based on similarity indices for A. marginata samples indicated a relatively high level of genetic variation in the populations from the three areas.

Morphometric Differentiation between Two Closely Related Achatinid Snails (Gastropoda: Achatinidae) of West Africa and Implications for the Conservation of &lt;i&gt;Achatina togoensis&lt;/i&gt; (Bequaert &amp; Clench, 1934)

“…The effectively useful traits for identification were selected based on the available taxonomic descriptions of the class Gastropoda from the literature [26] [27] [28]. A total of eight (8) traits were adopted for continuous measurements i.e.…”