Cytogenetic study of Anopheles albitarsis (Diptera: Culicidae) by C-banding and in situ hybridization

Abstract

The C-banding pattern and the size and location of the nucleolar organizer regions (NORs) are described for the first time in Brazilian populations of Anopheles (Nyssorhynchus ) albitarsis sensu lato. C-banding revealed variation in the size of the centromeric heterochromatic blocks in autosomal chromosomes and in the acrocentric (X) and puntiform (Y) sex chromosomes. Fluorescence in situ hybridization showed that the NORs were located in the pericentromeric region of the sex (XX/XY) chromosomes and that this coincided with the number and location of centromeric constitutive heterochromatin blocks previously revealed by C-banding. The NORs varied in size among the homologues of the three populations. These findings of the populations studied support the hypothesis that the stability of NORs in the A. albitarsis complex is characterized by the presence of clustered and conserved sites in a unique pair of chromosomes.

Salivary Polytene Chromosome Map of Anopheles darlingi, the Main Vector of Neotropical Malaria

“…In the chromosome arm 2R, sections 6, 7, 8, 9, 10, 12, 13, and 15 were subdivided into 4, 3, 4, 5, 5, 5, 5, and 5 subsections, respectively. In the chromosome arm 2L, sections 16,17,19,20,21,22,23, and 24 were subdivided into 4, 3, 4, 4, 3, 4, 3, 3, and 3 subsections, respectively. Chromosome arm 3R shows the sections 26, 27, 28, 29, 30, 33, and 34, which were subdivided into 3, 3, 4, 3, 3, 3, and 3 subsections, respectively.…”

“…11 This pattern is observed in the majority of the species in the Nyssorhynchus subgenus, including Anopheles strodei , Anopheles albimanus , Anopheles aquasalis , Anopheles noroestensis , and Anopheles argyritarsis . 17 Morphological variation was detected in the X chromosome, which was metacentric in A. aquasalis and A. noroestensis , A. strodei , A. albimanus , acrocentric in A. argyritarsis , 17,18 A. darlingi , 11 and A. albitarsis sensu latu, 19 whereas it is metacentric in A. aquasalis and A. noroestensis , 17 and submetacentric in A. nuneztovari. 11 This pattern is observed also in Anopheles cruzii and Anopheles bellator of subgenus Kerteszia , 20,21 A. subpictus , 22 and A. gambiae species complex, serie Pyretophorus, subgenus Cellia .…”

Chromosomal localization and partial sequencing of the 18S and 28S ribosomal genes from Bradysia hygida (Diptera: Sciaridae)

“…Although research related to rRNA in diptera is scarce, we found that in many species of culicidae (Rafael et al, 2006) and tephritidae (Drosopoulou et al, 2012), the rRNA genes are usually localized in sex chromosomes; however, in some cases (e.g., Rhagoletis pomonella), it can be found in autosomal chromosomes (Procunier and Smith, 1993).…”

Physical mapping of 18S rDNA and heterochromatin in species of family Lygaeidae (Hemiptera: Heteroptera)

“…In Hemiptera, these studies have revealed important findings compared to those obtained in other groups of insects (Caterino et al, 2000). Besides 18S rDNA, other classes of repetitive DNA with heterochromatic sequences have also been widely used as cytogenetic markers for comparisons across different groups of insects such as in Orthoptera (Cabral-de-Mello et al, 2011), Coleoptera (Almeida et al, 2010), Diptera (Rafael et al, 2006), and Heteroptera Bardella et al, 2010;Grozeva et al, 2010;Panzera et al, 2012). Some types of repetitive DNA can be chromosomespecific, such as those mostly found in Drosophila melanogaster (Bonaccorsi and Lohe, 1991) and those found on the sex chromosomes in species such as Megoura (Bizzaro et al, 1996).…”