title: Genetic structuring and fixed polymorphisms in the gene period among natural populations of Lutzomyia longipalpis in Brazil.
abstract: BACKGROUND
  Even one hundred years after being originally identified, aspects of the taxonomy of the sand fly Lutzomyia longipalpis, the principal vector of Leishmania infantum in the Americas, remain unresolved for Brazilian populations of this vector. The diversity of morphological, behavioral, biochemical, and ethological characters, as well as the genetic variability detected by molecular markers are indicative of the presence of a complex of species.
  
  
  METHODS
  In this study, a 525 bp fragment of the period gene was used to evaluate sympatric populations of L. longipalpis. A combination of probabilistic methods such as maximum likelihood and genetic assignment approach to investigate sympatric species of L. longipalpis were applied in three populations of Northeast Brazil.
  
  
  RESULTS
  Fixed polymorphisms in geographically isolated populations of L. longipalpis from two localities in the state of Ceará and one in the state of Pernambuco, Brazil, was identified in a 525 bp fragment of the gene period (per). Our results suggest a direct relationship between the number of spots found in males' tergites and the genetic variation in cryptic species of L. longipalpis. The fragment used in this study revealed the nature of the ancestral morphotype 1S.
  
  
  CONCLUSIONS
  New polymorphisms were identified in the gene per which can be used as a genetic barcode to sympatric taxonomy of L. longipalpis. The per gene fragment confirmed the presence of two siblings species of L. longipalpis in Sobral and showed that these same species are present in two other localities, representing an expansion within the L. longipalpis species complex with regards to the states of Ceará and Pernambuco.
authors.affiliation: Departamento de Genética, Universidade Federal de Pernambuco, Avenida da Engenharia S/N, Cidade Universitária, 50.740-600, Recife, Pernambuco, Brazil. cjrs@ig.com.br.
authors.forename: César Raimundo
authors.initials: CR
authors.lastname: Lima Costa
authors.affiliation: Departamento de Genética, Universidade Federal de Pernambuco, Avenida da Engenharia S/N, Cidade Universitária, 50.740-600, Recife, Pernambuco, Brazil. moisestsf@hotmail.com.
authors.forename: Moises Thiago de Souza
authors.initials: MT
authors.lastname: Freitas
authors.affiliation: Departamento de Genética, Universidade Federal de Pernambuco, Avenida da Engenharia S/N, Cidade Universitária, 50.740-600, Recife, Pernambuco, Brazil. cjsantifigo@hotmail.com.
authors.forename: Carlos Alberto
authors.initials: CA
authors.lastname: Santiago Figueirêdo
authors.affiliation: Departamento de Genética, Universidade Federal de Pernambuco, Avenida da Engenharia S/N, Cidade Universitária, 50.740-600, Recife, Pernambuco, Brazil. nadibr2@yahoo.com.br.
authors.forename: Nádia Consuelo
authors.initials: NC
authors.lastname: Aragão
authors.affiliation: Departamento de Genética, Universidade Federal de Pernambuco, Avenida da Engenharia S/N, Cidade Universitária, 50.740-600, Recife, Pernambuco, Brazil. lidianegomesp@hotmail.com.
authors.forename: Lidiane Gomes
authors.initials: LG
authors.lastname: da Silva
authors.affiliation: Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de Santa Catarina, Campus Reitor João David Ferreira Lima, 88040-900, Florianópolis, Santa Catarina, Brazil. cbrisolamarcondes@gmail.com.
authors.forename: Carlos Brisola
authors.initials: CB
authors.lastname: Marcondes
authors.affiliation: Centro de Controle de Zoonoses, Rua Finlândia S/N, Parque Silvana II, 62010-970, Sobral, Ceara, Brazil. netovet1@hotmail.com.
authors.forename: Raimundo Vieira
authors.initials: RV
authors.lastname: Dias
authors.affiliation: Departamento de Microbiologia, Centro de Pesquisas Aggeu Magalhaes, Avenida Professor Moraes Rego S/N, Cidade Universitária, 50740-465, Recife, Pernambuco, Brasil. cristina@cpqam.fiocruz.br.
authors.forename: Tereza Cristina
authors.initials: TC
authors.lastname: Leal-Balbino
authors.affiliation: Departamento de Genética, Universidade Federal de Pernambuco, Avenida da Engenharia S/N, Cidade Universitária, 50.740-600, Recife, Pernambuco, Brazil. manubrsouza@gmail.com.
authors.forename: Manuela Barbosa Rodrigues
authors.initials: MB
authors.lastname: Souza
authors.affiliation: Department of Entomology, Kansas State University, W. Waters Hall 123, 66506-400, Manhattan, KS, USA. mortigao@k-state.edu.
authors.forename: Marcelo
authors.initials: M
authors.lastname: Ramalho-Ortigão
authors.affiliation: Departamento de Genética, Universidade Federal de Pernambuco, Avenida da Engenharia S/N, Cidade Universitária, 50.740-600, Recife, Pernambuco, Brazil. vqbalbino@gmail.com.
authors.forename: Valdir de Queiroz
authors.initials: Vde Q
authors.lastname: Balbino
mesh_terms: D063147:Animal Distribution; D000818:Animals; D001483:Base Sequence; D001938:Brazil; D004247:DNA / Q000235:genetics; D005786:Gene Expression Regulation / Q000502:physiology*; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D010802:Phylogeny; D011110:Polymorphism, Genetic; D011576:Psychodidae / Q000235:genetics*
chemical_list: D019476:Insect Proteins; D004247:DNA