Flies from the Drosophilidae family have been suggested as appropriated for the
assessment of the effects of habitat fragmentation (e.g., Mata et al., 2010MATA, RA., MCGEOCH, M. and TIDON, R., 2010. Drosophilids (Insecta,
Diptera) as Tools for Conservation Biology. Natureza & Conservação, vol. 8,
no. 1, p. 60-65. http://dx.doi.org/10.4322/natcon.00801009.
http://dx.doi.org/10.4322/natcon.0080100...
). Cavasini et
al. (2014)CAVASINI, R., BUSCHINI, MLT., MACHADO, LPB. and MATEUS, RP., 2014.
Comparison of Drosophilidae (Diptera) assemblages from two highland Araucaria
Forest fragments, with and without environmental conservation policies.
Brazilian Journal of Biology, vol. 74, no. 4. evaluated the Drosophilidae assemblages of Araucaria Forest
fragments in Guarapuava/PR (southern of Brazil), including one studied here. They
concluded that the areas are in intermediate state of conservation, and the size of the
preserved area and/or connection with other fragments are important and should be
considered for the establishment of conservation units. In this context, we analyzed the
genetic variability of D. maculifrons (Duda, 1927), a forest dwelling
species that belongs to the guaramunu group, collected in two
conservation units of highland Araucaria Forest fragments in Guarapuava/PR, in order to
establish parameters of genetic diversity and levels of gene flow. Thus, we expect to
obtain insights about the connectivity level and its importance to conservation.
The two areas (Parque Municipal das Araucárias – PMA: 25° 23’ 36” S, 51° 27’ 19” W, with
43 ha; Parque Municipal São Francisco da Esperança – SSF: 25° 03’ 52” S, 51° 17’ 37” W,
with 84,7 ha) are located 36 kilometers apart from each other and at about 1,100 m above
the sea level. The genetic variability was analyzed using nine allozymatic
(Est, Gpdh, Idh,
Me, Pgm, Hk,
Mdh-1, Mdh-2 and Mdh-3 – Mateus and Sene, 2003Mateus, RP. and Sene, FM., 2003. Temporal and spatial allozyme
variation in the South American cactophilic Drosophila antonietae (Diptera;
Drosophilidae). Biochemical Genetics, vol. 41, no. 7-8, p. 219-233.
http://dx.doi.org/10.1023/A:1025506301239. PMid:14587665
http://dx.doi.org/10.1023/A:102550630123...
) and nine microsatellite
loci (034, 053, 057, 087, 095, 096, 099, 102 and 118 – Laborda et al., 2009LABORDA, PR., KLACZKO, LB. and SOUZA, AP., 2009. Drosophila
mediopunctata microsatellites. II: Cross- species amplification in
the tripunctata group and other species.
DrosophilaConservation Genetics Resources, vol. 1, no. 1,
p. 281-296. http://dx.doi.org/10.1007/s12686-009-9069-9.
http://dx.doi.org/10.1007/s12686-009-906...
). For allozyme data, the parameter Θ and migration
rates M were inferred through the MIGRATE-n v3.6.4 software (Beerli, 2012BEERLI, P., 2012. MIGRATE documentation (version 3.2.1). Technical
Report. Available from: <http://popgen.sc.fsu.edu>. Access in: 28 Apr.
2014.). Assuming an average mutation rate of
1.28x10–6 per locus per generation (Voelker et al., 1980Voelker, RA., Schaffer, HE. and Mukai, T., 1980. Spontaneous
allozyme mutations in : rate of occurrence and nature of the mutants.
Drosophila melanogasterGenetics, vol. 94, no. 4, p.
961-968. PMid:17249027.), average Θ estimates were translated to estimates of
average effective population sizes (i.e. Ne = Θ/4μ) for each population.
The allozymatic genetic diversities (Ho) for both populations (Table 1) were lower than those found by Saavedra et al. (1995)SAAVEDRA, CCR., VALENTE, VLS. and NAPP, M., 1995. An
ecological/genetic approach to the study of enzymatic polymorphisms in
Drosophila maculifrons.Brazilian Journal of Genetics, vol.
18, no. 2, p. 147-164. for D. maculifrons
(0.2831) in the Rio Grande do Sul state, Brazil. They were also lower than those found
by Machado et al. (2012)MACHADO, LPB., SILVA, DC., SIMÃO, DP. and MATEUS, RP. 2012. Spatial
variation of genetic diversity in Drosophila species from two different South
America environments. In CALISKAN, M. Genetic variation in animals. Rijeka:
Intech. p. 45-62.. http://dx.doi.org/10.5772/32971.
http://dx.doi.org/10.5772/32971...
for D.
ornatifrons (Duda, 1927), a closely related species of D.
maculifrons, collected in the same areas (PMA – 0.3609; SSF – 0.4060). It
is noteworthy that, for allozymes, D. maculifrons and D.
ornatifrons of SSF showed higher genetic diversity. For microsatellites,
the Ho values obtained (Table 1) were lower than
those found by Heinz (2012)HEINZ, NP., 2012. Variabilidade molecular sazonal de
Drosophila mediopunctata (Diptera: Drosophilidae).
Guarapuava: UNICENTRO. Dissertação de Mestrado. for D.
mediopunctata (Dobzhansky and Pavan, 1943), a closely related species of
the tripunctata group, in two areas of Guarapuava/PR, PMA (0.5385) and
Fazenda Brandalise (0.5062).
Allozymes and microsatellites genetic variability parameters for two Drosophila maculifrons natural populations from Guarapuava/PR (Brazil).
For allozymes, the genetic distance indexes resulted in a low to moderate differentiation
between PMA and SSF (Nei’s D = 0.0248; Fst = 0.0556). Low genetic
differentiation for D. maculifrons was also recently detected for COI
and COII mitochondrial genes (Cenzi de Ré et al.,
2014CENZI DE RÉ, FC., GUSTANI, EC., OLIVEIRA, APF., MACHADO, LPB.,
MATEUS, RP., LORETO, ELS. and ROBE, LJ., 2014. Brazilian populations of .
Drosophila maculifrons (Diptera, Drosophilidae): low
diversity levels and signals of a population expansion after the Last Glacial
MaximumBiological Journal of the Linnean Society. Linnean Society of London,
vol. 112, no. 1, p. 55-66. http://dx.doi.org/10.1111/bij.12244.
http://dx.doi.org/10.1111/bij.12244...
). On the other hand, for microsatellites, low genetic differentiation
was not observed (D = 0.4174; Fst = 0.0901), probably because of its
high variability. Therefore, despite the two populations are somewhat genetically
similar (see Table 1), they depict some degree
of differentiation. This is corroborated by PMA showing one locus less than SSF for both
markers, and both populations presented several exclusive alleles (PMA: allozymes - 5;
microsatellites - 13; SSF: allozymes - 3; microsatellites - 33).
The migration rates and population size estimations showed that SSF supplies much more
migrants to PMA than otherwise (MSSF→PMA = 2,160; MPMA→SSF =
12.416), contributing to a higher average effective population size to PMA
(NePMA = 4.629 x 1016; NeSSF = 8.496 x
103). Theses results indicated that size (of the fragment) matters
regarding migration. SSF is a conservation unit twice larger than PMA (not taking in
account that SSF is surrounded by several other fragments of Araucaria forest in private
properties, which must double or even triple the total size of the area, and PMA is
surrounded by crop plantations and Guarapuava city limits) and this is probably driving
the high rates of migrants between these areas (e.g., Schiffer et al., 2007Schiffer, M., Kennington, WJ., Hoffmann, AA. and Blacket, MJ., 2007.
Lack of genetic structure among ecologically adapted populations of an
Australian rainforest Drosophila species as indicated by microsatellite markers
and mitochondrial DNA sequences. Molecular Ecology, vol. 16, no. 8, p.
1687-1700. http://dx.doi.org/10.1111/j.1365-294X.2006.03200.x.
PMid:17402983
http://dx.doi.org/10.1111/j.1365-294X.20...
). Moreover, the amount of migration detected is
probably the main cause of the low genetic differentiation found for allozymes here, but
other evolutionary forces, such as genetic drift and mutation rates, for example, must
be in action to generate and maintain the differentiation detected for
microsatellites.
Acknowledgements
Funds were provided by CNPq (RP Mateus, grant number 479719/2011-0), SETI/Fundação Araucária (R. P. Mateus, grant number 868/2012); CAPES (DC Silva Master’s Fellowship); FINEP; and UNICENTRO.
References
- BEERLI, P., 2012. MIGRATE documentation (version 3.2.1). Technical Report. Available from: <http://popgen.sc.fsu.edu>. Access in: 28 Apr. 2014.
- CAVASINI, R., BUSCHINI, MLT., MACHADO, LPB. and MATEUS, RP., 2014. Comparison of Drosophilidae (Diptera) assemblages from two highland Araucaria Forest fragments, with and without environmental conservation policies. Brazilian Journal of Biology, vol. 74, no. 4.
- CENZI DE RÉ, FC., GUSTANI, EC., OLIVEIRA, APF., MACHADO, LPB., MATEUS, RP., LORETO, ELS. and ROBE, LJ., 2014. Brazilian populations of . Drosophila maculifrons (Diptera, Drosophilidae): low diversity levels and signals of a population expansion after the Last Glacial MaximumBiological Journal of the Linnean Society. Linnean Society of London, vol. 112, no. 1, p. 55-66. http://dx.doi.org/10.1111/bij.12244.
» http://dx.doi.org/10.1111/bij.12244 - HEINZ, NP., 2012. Variabilidade molecular sazonal de Drosophila mediopunctata (Diptera: Drosophilidae). Guarapuava: UNICENTRO. Dissertação de Mestrado.
- LABORDA, PR., KLACZKO, LB. and SOUZA, AP., 2009. Drosophila mediopunctata microsatellites. II: Cross- species amplification in the tripunctata group and other species. DrosophilaConservation Genetics Resources, vol. 1, no. 1, p. 281-296. http://dx.doi.org/10.1007/s12686-009-9069-9.
» http://dx.doi.org/10.1007/s12686-009-9069-9 - MACHADO, LPB., SILVA, DC., SIMÃO, DP. and MATEUS, RP. 2012. Spatial variation of genetic diversity in Drosophila species from two different South America environments. In CALISKAN, M. Genetic variation in animals. Rijeka: Intech. p. 45-62.. http://dx.doi.org/10.5772/32971.
» http://dx.doi.org/10.5772/32971 - MATA, RA., MCGEOCH, M. and TIDON, R., 2010. Drosophilids (Insecta, Diptera) as Tools for Conservation Biology. Natureza & Conservação, vol. 8, no. 1, p. 60-65. http://dx.doi.org/10.4322/natcon.00801009.
» http://dx.doi.org/10.4322/natcon.00801009 - Mateus, RP. and Sene, FM., 2003. Temporal and spatial allozyme variation in the South American cactophilic Drosophila antonietae (Diptera; Drosophilidae). Biochemical Genetics, vol. 41, no. 7-8, p. 219-233. http://dx.doi.org/10.1023/A:1025506301239. PMid:14587665
» http://dx.doi.org/10.1023/A:1025506301239 - SAAVEDRA, CCR., VALENTE, VLS. and NAPP, M., 1995. An ecological/genetic approach to the study of enzymatic polymorphisms in Drosophila maculifrons.Brazilian Journal of Genetics, vol. 18, no. 2, p. 147-164.
- Schiffer, M., Kennington, WJ., Hoffmann, AA. and Blacket, MJ., 2007. Lack of genetic structure among ecologically adapted populations of an Australian rainforest Drosophila species as indicated by microsatellite markers and mitochondrial DNA sequences. Molecular Ecology, vol. 16, no. 8, p. 1687-1700. http://dx.doi.org/10.1111/j.1365-294X.2006.03200.x. PMid:17402983
» http://dx.doi.org/10.1111/j.1365-294X.2006.03200.x - Voelker, RA., Schaffer, HE. and Mukai, T., 1980. Spontaneous allozyme mutations in : rate of occurrence and nature of the mutants. Drosophila melanogasterGenetics, vol. 94, no. 4, p. 961-968. PMid:17249027.
Publication Dates
-
Publication in this collection
Jan-Mar 2015
History
-
Received
26 May 2014 -
Accepted
30 June 2014