Fig. 13From: Evolutionary pattern of karyotypes and meiosis in pholcid spiders (Araneae: Pholcidae): implications for reconstructing chromosome evolution of araneomorph spidersMeiosis of pholcid males, diffuse stage and pattern of chiasmata. P = pericentric chiasma, T = sex chromosome trivalent, X = X chromosome, II = bivalent with two chiasmata, III = bivalent with three chiasmata. a Artema nephilit (X1X2Y), early diffuse stage. Bivalents considerably decondensed, sex chromosomes form positively heteropycnotic body; b Metagonia sp. (X1X2Y), late diffuse stage, bivalents condensed but without well differentiated chiasmata. Sex chromosomes form a highly condensed body; c Artema nephilit (X1X2Y), diakinesis. Bivalents retain low condensation, except for terminal regions; d Physocyclus dugesi (X0), diplotene. Some bivalents have a pericentric chiasma. Centromere regions are dark, more condensed; e Modisimus cf. elongatus (X0), diplotene. Sex chromosome is positively heteropycnotic. Most bivalents have pericentric chiasma. Centromeric regions are dark, more condensed; f Chisosa diluta (X0), metaphase I. Most bivalents have two chiasmata. Bar = 10 µmBack to article page