Prosimulium frontatum, TERTERYAN, 1956

Adler, Peter H., S, Ümit & Irin, 2014, Cytotaxonomy of the Prosimulium (Diptera: Simuliidae) of Western Asia, Zoological Journal of the Linnean Society 171 (4), pp. 753-768 : 758

PROSIMULIUM FRONTATUM TERTERYAN

Two samples totalling 27 larvae of this species were available from north-western Armenia. Larvae were characterized by four fixed inversions: IS-20, IS-23 ( Fig. 2 ), IL-12 ( Fig. 6A ), and IIIL-25 ( Fig. 11 ). Sex chromosomes were microscopically undifferentiated (X 0 Y 0). The transformed centromere region of chromosome I was markedly elongated; for example, section 18′ had additional band elaboration and section 19′ consistently was stretched ( Fig. 2 ), compared with the more compact condition in the other studied taxa ( Figs 4 , 5 ). Two autosomal inversions, IS-24 ( Fig. 2 ) and IIS- 12 ( Fig. 8B ), were found in more than two-thirds of the homologues ( Table 2). Ectopic pairing of centromere bands was infrequent. Six larvae carried infections with a probable new species of microsporidium with spores similar to those of Weiseria laurenti Doby & Saguez .

Figures

Figure 2. Chromosome arm IS of Prosimulium frontatum (female). Relative to the standard sequence, IS-20, IS-23, and IS-24 are present and their breakpoints identified by arrows. Ordering the chromosome fragments indicated by the letters ‘a’ to ‘l’ will produce the standard sequence. Fixed rearrangements are italicized and polymorphic rearrangements are in standard type. Abbreviation: C, centromere.

Figure 4. Chromosome arm IS of Prosimulium rachiliense cytoform ‘B’ (male). Relative to the standard sequence, IS-20 is present. Limits of inversion IS-21 of cytoform ‘A’ are indicated by a bracket. Fixed rearrangements are italicized and polymorphic rearrangements are in standard type. Abbreviations: C, centromere; “3”, 3 heavy marker.

Figure 5. Chromosome arm IS of Prosimulium tomosvaryi. A, female, showing the X sequence, represented by IS-14; B, male, showing the X (upper homologue) and Y (lower homologue = standard) sequences. Abbreviation: hb, location of heteroband 18hb.

Figure 6. Chromosome arm IL. A, Prosimulium frontatum (female; sections 23–44). Relative to the standard sequence, IL-12 is present. B, base of chromosome IL of Prosimulium rachiliense cytoform ‘A’ (male) with the IL-10 sequence. Fixed rearrangements are italicized and polymorphic rearrangements are in standard type. Abbreviation: N.O, nucleolar organizer.

Figure 8. Chromosome arm IIS. A, Prosimulium tomosvaryi (female). Relative to the standard sequence, IIS-3 and IIS- 11 are present. B, Prosimulium frontatum (female) showing heterozygous inversion IIS-12; its breakpoints are indicated by arrows on the standard homologue. Limits of IIS-13 of Prosimulium rachiliense ‘B’ are indicated by a bracket. Fixed rearrangements are italicized and polymorphic rearrangements are in standard type. Abbreviation: RoB, ring of Balbiani.

Figure 11. Chromosome arm IIIL of Prosimulium rachiliense cytoform ‘A’ (male), showing the standard sequence. Limits of IIIL-21–IIIL-24 of P. rachiliense ‘A’, IIIL-25 of Prosimulium frontatum, and IIIL-26 and IIIL-27 of Prosimulium tomosvaryi are indicated by brackets. Fixed rearrangements are italicized and polymorphic rearrangements are in standard type. Abbreviations: C, centromere; hb, location of heteroband 84hb of P. tomosvaryi; hc, location of extra heterochromatin (85hc) of P. tomosvaryi; hc(r) and hc(t), extra heterochromatin of P. rachiliense ‘A’ and P. tomosvaryi, respectively; s, shield; t, triad.