Regular segregation of the XY1Y2 trivalent and univalency in male meiosis of Artibeus lituratus (Phyllostomidae

PIGOZZI MI; SOLARI AJ

BIOCELL

INST HISTOL EMBRIOL-CONICET

Lugar: Mendoza; Año: 1994 p. 1 - 1

0327-9545

The pairing behaviour and segregation of the sex trivalent (XY1Y2) of Artibeur lituratus has been study in light microscopy spreads. During first propahse a trivalent is regularly formed with the Y1 and the Y2 chromosomes attached to different arms of theX chromosome. An end-to-end associationis maintained  between primitive sex chromosomes in this trivalent. The alternate orientation and the balanced segregation of the components of the trivalent have been ascertained from the quantitative analysis of metaphase II cells. The presence of a univalent Y1 in a number of first meiotic divisions and its artefactual origin is discussed. The preservation of the usual X-Y pairing in translocated sex chromosomes is assumedto prevent the formation of aneuploid gametes.