TY - JOUR T1 - Ultrastructural analysis of the X1X2X3O sex chromosome system during the spermatogenesis of Tegenaria domestica (Arachnida) JF - Journal of Cell Science Y1 - 1982 A1 - Benavente, R. A1 - Wettstein, R. A1 - Papa, M. SP - 411 EP - 422 KW - behaviour] [Sex determination genetics / / structure & behaviour during KW - Cytogenetics KW - Gametogenesis KW - Genetics KW - Reproduction KW - spermatogenesis] [Chromosomes / / ]. KW - structure & KW - Tegenaria domestica (Araneae). KW - Tegenaria domestica [Spermatogenesis / / Sex chromosomes AB - An ultrastructural study was performed on the sex chromosomes (.male. X1X2X3O) during the spermatogenesis of T. domestica (Arachnida, Agelenidae). This study was carried out using random and serially cut sections. During pachytene and diplotene the 3 X chromosomes are longitudinally paired. Each of these consists of a central core of condensed chromatin, surrounded by a field of dense chromatin projections through which the chromosomes are in contact with one another. These projections may be responsible for the recognition and pairing of the sex chromosomes and in some way participate in their non-disjunction during anaphase I. A study of the structure and behavior of the sex chromosomes during spermatogenesis is also presented. The available information on non-synaptonemal complex-mediated chromosome pairing and a systematization of sex chromosome structure in spiders are discussed. VL - 58 SN - 0021-9533 UR - ://ZOOREC:ZOOR11900036561 N1 - ZOOR11900036561 ER -