Animal Molecular Breeding 2015, Vol. 5, No. 1, 1-8
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(Abere and Lameed, 2008). The high iron content of
snail meat is considered important in the treatment of
anaemia and in the past, the meat was recommended as
a means of combating ulcers and asthma in many local
communities. In addition to the nutritional value of the
meat, recent studies have demonstrated that a glandular
substance from edible snails causes agglutination of
certain bacteria, which could cause ailments such as
whooping cough.
Though the meat is usually light black in colour, lately
a completely different variety of giant African land
snail, with albino body pigmentation, has become quite
commonly noticeable in many parts of the forest zone
of Nigeria, especially in the south eastern part, where
the gastropods have, naturally, become quite a source
of curiosity to many people. Intriguingly, these albino
snails appear to be predominating, as they are not
consumed as food due to the common belief that they
are poisonous and there is something undesirable or
freakish about them (personal observation).
To exploit microbial, plant or animal genetic resources
it is important that a detailed knowledge of the amount
of genetic variation that exists within the species is
known. Molecular markers, which help in the detection
of differences in the genetic information carried by
different individuals, are highly useful and can be used
as valuable tools to assess and exploit genetic diversity,
varietal classification, and germplasm identification of
the genetic variability that exists within species for
purposes of their improvement. Of the different
molecular markers currently available, random
amplified polymorphic DNA (RAPD) fingerprinting,
in which random fragments of DNA are amplified from
DNA samples using short, arbitrary primers, is highly
preferred by many researchers as one of the effective
methods for identification of genetic diversity amongst
populations of same species (Jordano and Godboy, 2000;
Tsuda and Ide, 2004). Besides that, RAPD markers also
show levels of polymorphism similar to isoenzyme
markers and can also target and amplify a large number
of loci (Bartish et al., 1999; Lez et al., 2002).
Although RAPD markers have their limitations and
drawbacks, they are considered as one of the most
effective genetic markers used in recent times as they
serve as powerful tools for discerning different gene
loci within plant and animal germplasm and for
studying evolutionary relationships between species.
This technique requires no prior knowledge of the
genomic DNA as it needs only small amount of DNA
(Hadrys et al., 1992). Moreover, polymorphism can be
detected in closely related organisms using RAPD
markers.
Generally, there is paucity of information on the
genetic diversity of giant African land snails. A search
of the literature shows that an assessment of genetic
diversity amongst giant African land snail varieties by
DNA-based markers has not been undertaken by any
research group. Consequently, the current study was
designed to determine if there were genetic differences
amongst the black and albino-bodied forms of giant
African land snails seen in different parts of the
lowland humid tropics in southern Nigeria using
RAPD fingerprinting.
1 Materials and Methods
1.1
Sample size and morphometric analysis
Sixteen (16) giant African land snails consisting of nine
(9) samples with meat that was black and seven (7) that
was albino were procured from three different locations
(Ekpoma in Edo State, 6.75° N, 6.13° E; Udua
Akpananem in Akwa Ibom State, 5.03°N, 7.92°E;
and Calabar in Cross River State, 4.95°N, 8.33°E) of
Nigeria. The snails were kept alive and maintained
under moist conditions to ensure their survival. They
were fed with fresh leaves, fruits and succulent plant
parts for two weeks before being subjected to
morphometric and genetic analyses.
Morphometric evaluation of shell variations (size,
shape and colour) was performed using multivariate
methods. The shell of each snail was described by five
measurements using veneer caliper (MITUTOYO
500-752-10 Digital caliper IP67 ABS 6"/150MM;
Spain). The shell characteristics evaluated in the
current study included the height of shell, width of
shell, spire length, aperture height, and aperture width
and was conducted according to Madec and Bellido
(2007). These five direct measurements of the shell
characteristics of the snails was performed to
determine whether the species under study can be
