Psitticimex uritui (Lent & Abalos, 1946)

Poggio, Maria G., Bressa, Maria J., Papeschi, Alba G., Iorio, Osvaldo Di & Turienzo, Paola, 2009, Insects found in birds’ nests from Argentina: cytogenetic studies in Cimicidae (Hemiptera) and its taxonomical and phylogenetic implications, Zootaxa 2315 (1), pp. 39-46 : 42

Psitticimex uritui

This species possesses 2n = 31 / 32 = 28 + X 1 X 2 Y / 28 + X 1 X 1 X 2 X 2 (male/female), with all the chromosomes of similar size ( Fig. 2a ). The course of meiosis is similar to that described for A. furnarii . During early male prophase I the three sex chromosomes are positively heteropycnotic. Autosomes gradually condense during leptotene, zygotene, and pachytene, but no diplotene or diakinesis is observed, i.e., meiosis is achiasmatic. At metaphase I, homologous chromosomes lie side by side and are connected with each other through their medial region by non-chiasmatic associations. The 14 autosomal bivalents and the three sex univalents are arranged with their long axes perpendicular to the spindle pole ( Fig. 2b ). At anaphase I, autosomes segregate reductionally whereas the sex chromosomes segregate chromatids (equational division). At metaphase II, autosomes dispose in a ring configuration and the X 1, X 2, and Y chromatids form a pseudotrivalent ( Fig. 2c ). At anaphase II, autosomes segregate sister chromatids; and the X 1 and X 2 chromatids segregate from the Y. Telophase II nuclei have 16 (14 + X 1 X 2) or 15 (14 + Y) chromosomes.

Figures

FIGURE 2. Male meiotic chromosomes of Psiticimex uritui: a, prometaphase I; b, metaphase I; c, metaphase II. Arrows: sex chromosomes. N: nucleolus. Chromosomes are stained with 2 % iron acetic haematoxylin. Bar = 10 µm.