SciELO - Scientific Electronic Library Online

 
vol.101 issue8Hitchhiking Trypanosoma cruzi minicircle DNA affects gene expression in human host cells via LINE-1 retrotransposon author indexsubject indexarticles search
Home Pagealphabetic serial listing  

Memórias do Instituto Oswaldo Cruz

Print version ISSN 0074-0276

Abstract

MARRELLI, Mauro Toledo; SALLUM, Maria Anice Mureb  and  MARINOTTI, Osvaldo. The second internal transcribed spacer of nuclear ribosomal DNA as a tool for Latin American anopheline taxonomy: a critical review. Mem. Inst. Oswaldo Cruz [online]. 2006, vol.101, n.8, pp. 817-832. ISSN 0074-0276.  http://dx.doi.org/10.1590/S0074-02762006000800002.

Among the molecular markers commonly used for mosquito taxonomy, the internal transcribed spacer 2 (ITS2) of the ribosomal DNA is useful for distinguishing among closely-related species. Here we review 178 GenBank accession numbers matching ITS2 sequences of Latin American anophelines. Among those, we found 105 unique sequences corresponding to 35 species. Overall the ITS2 sequences distinguish anopheline species, however, information on intraspecific and geographic variations is scarce. Intraspecific variations ranged from 0.2% to 19% and our analysis indicates that misidentification and/or sequencing errors could be responsible for some of the high values of divergence. Research in Latin American malaria vector taxonomy profited from molecular data provided by single or few field capture mosquitoes. However we propose that caution should be taken and minimum requirements considered in the design of additional studies. Future studies in this field should consider that: (1) voucher specimens, assigned to the DNA sequences, need to be deposited in collections, (2) intraspecific variations should be thoroughly evaluated, (3) ITS2 and other molecular markers, considered as a group, will provide more reliable information, (4) biological data about vector populations are missing and should be prioritized, (5) the molecular markers are most powerful when coupled with traditional taxonomic tools.

Keywords : Anopheles; Neotropical; anophelines; malaria vectors; internal transcibed spacer 2; ITS2; taxonomy; systematics.

        · text in English     · pdf in English