del Cerro A L, Fernández A, Santos J L
Departamento de Genética, Universidad Complutense, Madrid, Spain.
Chromosome Res. 1996 Jan;4(1):69-75. doi: 10.1007/BF02254948.
Surface-spread synaptonemal complexes and chiasma distributions in spermatocytes with different C-banding patterns and chiasma distributions in oocytes were analyzed in the grasshopper Pyrgomorpha conica. Male meiosis was characterized by a proximal/distal chiasma localization and complete pairing of homologous chromosomes at pachytene. However, there were indications of a relationship between the frequency and location of pairing initiation sites and chiasma distribution. The presence of a proximal supernumerary segment in a medium-sized chromosome does not increase the mean cell chiasma frequency of carrier individuals compared with those lacking it but may modify chiasma distribution in at least some carrier bivalents. This effect could be related to heterosynapsis in the region near the segment. Mean cell chiasma frequency was significantly lower in females than in males. Females also showed altered chiasma distributions compared with males, with fewer proximal chiasmata and more interstitial and distal chiasmata.
在锥头蝗（Pyrgomorpha conica）中，分析了具有不同C带模式的精母细胞中的表面铺展联会复合体和交叉分布，以及卵母细胞中的交叉分布。雄性减数分裂的特征是交叉在近端/远端定位，并且在粗线期同源染色体完全配对。然而，有迹象表明配对起始位点的频率和位置与交叉分布之间存在关系。与缺乏近端额外片段的个体相比，中等大小染色体中存在近端额外片段并不会增加携带者个体的平均细胞交叉频率，但可能会改变至少一些携带者二价体中的交叉分布。这种效应可能与该片段附近区域的异源联会有关。雌性的平均细胞交叉频率显著低于雄性。与雄性相比，雌性的交叉分布也有所改变，近端交叉较少，间质和远端交叉较多。
