Volume 7, Number 1, 420-438, DOI: 10.1007/BF00329735

The chromosomes of the giant scale Aspidoproctus maximus louns. (Coccoidea-Margarodidae) with special reference to asynapsis and sperm formation

Sally Hughes-Schrader

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Abstract

1.  The chromosomes of the African scale, Aspidoproctus maximus Louns., number 5 in the male, 6 in the female; sex chromosomes are of the XO male, XX female type.
2.  Male meiosis is similar to that found in the Neotropical Llaveiini, with vesiculation of prophase nuclei, broadly dispersed polar centers, and divergent chromosomal fibers. The usual sequence of co-orientation and auto-orientation in meiosis is inverted; the chromosomes are autooriented at Metaphase I, and co-oriented at Metaphase II.
3.  Asynapsis of one pair of autosomes occurs in from 14% to 52% (in different individuals) of the primary spermatocytes. Regular segregation of asynaptic chromosomes is ensured by a secondary pairing during interkinesis.
4.  In spermiogenesis the chromosomes, linearly aligned, move out of the nucleus into the tail filament which forms a non-flagellated sperm.

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